SMITHSONIAN CONTRIBUTIONS TO BOTANY 0 NUMBER 87 

Genera of New World Eragrostideae 

(Poaceae : Chloridoideae) 

Paul M. Peterson, Robert D. Webster, 

and Jesus Valdes-Reyna 

SMITHSONIAN INSTITUTION PRESS 

Washington, D.C. 

1997 
ABSTRACT 

Peterson, Paul M., Robert D. Webster, and Jesus Valdes-Reyna. Genera of New World 

Eragrostideae (Poaceae: Chloridoideae). Smithsonian Contributions to Botany, number 87, 50 

pages, 1 table. 1997.-A comprehensive study of generic concepts, evaluation of taxonomic 

characters, and a revised classification is presented for the Eragrostideae of the New World. An 

original set of data, consisting of 88 characters recorded for 38 genera, was collected and 

analyzed to produce a dichotomous key, a synoptic key, and comparative descriptions. A 

detailed discussion is presented on the characters and the distribution of the character states. 

Remarks on the morphology, taxonomic history, and relationships among the species within 

each genus and among the genera of Eragrostideae are given. A new combination is proposed for 

Neeragrostis contrerasii. 

OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is 

recorded in the Institution’s annual report, Annals ofthe Smithsonian Institution. SERIES COVER 

DESIGN: Leaf clearing from the katsura tree Cercidiphyllum japonicum Siebold and Zuccarini. 

Library of Congress Cataloging-in-Publication Data 

Peterson, Paul M. 

Valdes-Re pa. 

Genera of New World Eragrostideae (Poaceae : Chloridoideae) / Paul M. Peterson, Robert D. Webster, and Jesus 

p. cm. - (Smithsonian contributions to botany ; no. 87) 

Includes bibliographical references (p. 47). 

1. Grasses-America- Classification. I. Webster, Robert D. (Robert Dale), 1950- . 11. Valdes-Rep, 

Jesus. 111. Title. IV. Series. 

QKl.S2747 no. 87 [QK495.G74] 580 sdc21 [584‘.9] 97-29204 

@ The paper used in this publication meets the minimum requirements of the American 

National Standard for Permanence of Paper for Printed Library Materials 239.48-1984. 
Contents 

Page 

Introduction ....................................... 1 

Materials and Methods ................................ 2 

Acknowledgments .................................. 3 

Key to the Eragrostideae of the New World ...................... Clave para Eragrostideae del Nuevo Mundo ...................... 12 

Synoptic Key to the New World Genera of the Eragrostideae ............ 17 

Taxonomy ........................................ 22 

ERAGROSTIDEAE ................................... 22 

1 . Allolepis .................................... 22 

2 . Bealia ..................................... 23 

3 . Blepharidachne ................................ 23 

4 . Blepharoneuron ................................ 24 

5 . Calamovilfa .................................. 25 

6 . Chaboissaea .................................. 25 

7 . Crypsis ..................................... 26 

8 . Dactyloctenium ................................ 26 

9 . Dasyochloa .................................. 27 

10 . Distichlis .................................... 27 

11 . Eleusine .................................... 28 

12 . Eragrostis ................................... 28 

13 . Erioneuron ................................... 29 

14 . Gouinia .................................... 30 

15 . Jouvea ..................................... 31 

16 . Leptochloa ................................... 31 

17 . Lycurus ..................................... 32 

18 . Monanthochloe ................................ 32 

19 . Muhlenbergia ................................. 33 

20 . Munroa ..................................... 34 

21 . Neeragrostis .................................. 35 

22 . Neesiochloa .................................. 35 

23 . Neyraudia ................................... 36 

24 . Pereilerna ................................... 36 

25 . Redfieldia ................................... 37 

26 . Reederochloa ................................. 38 

27 . Scleropogon .................................. 38 

28 . Sohnsia ..................................... 39 

29 . Sporobolus ................................... 39 

30 . Steirachne ................................... 40 

31 . Swallenia .................................... 40 

32 . Tetrachne ................................... 41 

33 . Trichoneura .................................. 41 

34 . Tridens ..................................... 42 

35 . Triplasis .................................... 43 

36 . Tripogon .................................... 43 

The Characters and Their Variation ........................... 3 

8 

iii 
iv SMITHSONIAN CONTRIBUTIONS TO BOTANY 

37 . Uniola ..................................... .14 

38 . Vaseyochloa .................................. 44 

Classification ...................................... 45 

Literature Cited ..................................... 47 
Genera of New World Eragrostideae 

(Poaceae: Chloridoideae) 

Paul M. Peterson, Robert D. Webster, 

and Jesus Valdes-Reyna 

Introduction from glumes. Glumes and valves [lemmas] rather similar in 

The Eragrostideae includes approximately 80 genera and 

1000 species, or about one-tenth of all grasses. These taxa are 

primarily distributed in the subtropical to tropical regions in 

arid climates, with centers of distribution in the savannahs of 

southern Africa and north central Mexico. In the New World, or 

Western Hemisphere, this study recognizes 38 genera and 

about 427 species, with the highest concentration in north 

central Mexico and the southwestern United States. 

Within the Eragrostideae there is considerable variation in 

morphology, anatomy, and cytology (Peterson, 1988, 1989; 

Peterson et al., 1989, 1993, 1995; Peterson and Annable, 1990, 

1991, 1992; Valdes-Reyna and Hatch, 1991; Peterson and 

Herrera A., 1996). It is difficult, if not impossible, to select 

diagnostic characteristics that exclusively delimit the Eragrostideae from other tribes in the Chloridoideae; however, the tribe 

commonly has paniculate inflorescences (occasionally racemose), laterally compressed or terete (rarely dorsiventral) 

spikelets, lemmas 3-nerved (occasionally 1 -nerved or more 

than 3-nerved), and disarticulation typically above the glumes 

(Peterson et al., 1995). 

In the Flora Capensis, Stapf (1898) first used the tribal name 

Eragrostideae ( Eragrosteae), where he placed four genera: 

Desmostachya (Ho0k.f. ) Stapf, Diplachne Beauv. (= Leptochloa P. Beauv.), Eragrostis Wolf, and Pogonarthria Stapf. 

Stapf (1898:3 16) used the following characteristics to distinguish this tribe: “Spikelets variously panicled sometimes 

spicate or subspicate. Florets usually numerous and far exerted 

Paul M. Peterson, Department of Botany, National Museum ofNatural 

History, Smithsonian Institution, Washington, D. C. 20560. Robert D. 

Webster, Systematic Botany and Mycology Laboratory, Agn‘culture 

Research Service, Bldg. 003, Room 235, BARC- West, Beltsville, 

Maryland 20705. Jesus Valdes-Reyna, Departamento de Botanica. 

Universidad Autonoma Agraria Antonio Narro, Buenavista, Saltillo, 

Coahuila, 253I5, Mexico. 

appearance. Valves [lemmas] membranous to chartaceous, very 

often olive green or olive grey, entire or 3-cleft, 3-nerved; 

nerves evanescent above or excurrent into bristles [awns]; 

side-nerves submarginal, glabrous or pubescent or finely ciliate 

below. Paleas often persistent or subpersistent.” Hubbard 

(1934) expanded the number of genera in the Eragrostideae to 

38 and added the following characteristics, among others, to the 

circumscription: spikelets usually with two or more fertile 

florets, disarticulation above the glumes, and spikelets laterally 

compressed. Pilger (1956) increased the number of taxa in the 

Eragrostideae to include 53 genera in six subtribes. Five of the 

six Eragrostideae subtribes (Eragrostinae, Lycurinae, 

Muhlenbergiinae, Scleropogoninae, and Sporobolinae) used by 

Pilger contain indigenous New World genera. The following 

characteristics were used by Pilger to differentiate the 

Eragrostideae from five other tribes in his subfamily Eragrostoideae (=Chloridoideae, in part): spikelets in loose or 

contracted panicles, these often compounded in racemes or 

spikes, branches spirally inserted; empty glumes usually 

shorter than the lemma; upper floret in many-flowered spikelets 

often sterile; lemma usually l-3-nerved, membranous to 

leathery; apex of the lemma entire, crenate, toothed, or lobed, if 

artistate, the awn arising from the midnerve; lemma nerves 

often hairy; stamens 2-3; fruits usually loosely surrounded by 

the palea, often becoming free; pericarp thin, often loosening 

and leaving the seeds naked; hilum small, basal; base 

chromosome number 10 or 8. A comparison of our classification of the Eragrostideae with that of Hitchcock and Chase 

(1951), Pilger (1954, 1956), Gould and Shaw (1983), Clayton 

and Renvoize (1986), and Watson and Dallwitz (1992) is given 

in Peterson et al., 1995. 

It seems appropriate initially to make a general statement 

concerning the relative number of species in the New World 

genera of the Eragrostideae on a world-wide basis. Of the 

species currently recognized in the tribe, about 67% are 

contained in the three largest genera (Eragrostis (350), 

1 
2 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

MuhEenbergia Schreb. (160), and Sporobolus R. Br. (160)). 

Eleven (about 29%) of the New World genera are monotypic. 

These include Allolepis Soderstr. & H.F. Decker, Bealia 

Scribn., Dasyochloa Willd. ex Rydb., Neesiochloa Pilg., 

Redfieldia Vasey, Reederochloa Soderstr. & H.F. Decker, 

Scleropogon Phil., Sohnsia Airy Shaw, Swallenia Soderstr. & 

H.F. Decker, Tetrachne Nees, and Vaseyochloa Hitchc. 

Fourteen (37%) of the New World genera contain two to four 

species. These include Blepharidachne Hack. (4), Blepharoneuron Nash (2), CalumoviIfa (A. Gray) Hack. (4), 

Chaboissaea E. Fourn. (4), Erioneuron Nash (3), Jouvea E. 

Fourn. (2), Lycurus Kunth (3), Monanthochloe Engelm. (2), 

Neerugrostis Bush (2), Neyraudia Hook. (2), Pereilema C. 

Presl (4), Steirachne Ekman (2), Triplasis P. Beauv. (2), and 

Uniola L. (4). Therefore, 66% of the New World genera 

encompass about 6% of the species world wide. Five New 

World genera have five to 10 species. These include Crypsis 

W.T. Aiton (S), Distichlis Raf. (6), Eleusine Gaertn. (9), 

Munrou Torr. (9, and Trichoneura Andersson (7). The 

remaining five New World genera (Dacfyloctenium Willd. 

(13), Gouinia E. Fourn. (12), Leptochloa (40), Tridens Roem. 

& Schult. (17), and Tripogon Roem. & Schult. (30)) have 11 to 

40 species. 

The objectives of this paper are to provide a synopsis of the 

38 native and introduced New World genera of the Eragrostideae and to provide keys in English and Spanish for ease in 

determination. In addition to the refined generic concepts 

provided, remarks on nomenclature, number of species in each 

genus, and habitat preference have been included. A provisional classification recognizing seven subtribes is given to 

elucidate probable phylogenetic relationships among the New 

World genera. 

MATERIALS AND METHODS 

The DELTA system (Dallwitz, 1974, 1980) was used in the 

collection and analysis of the taxonomic data presented in this 

paper. Initially, an ordered sequence of 89 characters and 

relevant character states was produced to account for all 

significant variation at the generic level for the New World 

Eragrostideae. Data for each of the characters were gathered in 

DELTA format on the 38 recognized genera from observations 

of all available specimens or from representative (20-50) 

specimens from each genus. All species of the smaller genera 

(1-15 species) or representative specimens of larger genera 

(more than 15 species) were examined. Recorded data were 

checked against specimens to insure correctness and uniformity 

in recording characters. These data were analyzed by the DELTA 

programs and were used for the production of the identification 

key, synoptic key, description of the tribe, generic descriptions, 

and some of the information contained in the remarks section 

for each genus. For additional information concerning these 

methods see Webster (1 988), Webster and Valdes-Reyna 

(1988), Webster et al. (1989), and Webster (1992a, 1992b). 

A reliability weight was given to each character and was 

used for the production of the identification key and for the 

selection of characters for the diagnosis within the descriptions. 

Assessment of reliability was based on the degree of 

consistency within a genus and on how well the character could 

be applied. For example, if a character was easy to determine 

and was consistent within a genus then it was given a higher 

reliability than a character that was difficult to determine and 

was variable between the species of the genus. This weight, the 

settings of other DELTA parameters (i.e., REIASE, ABASE, 

VARYWT, etc.), and how well the characters separated taxa into 

equal groups were important parameters influencing the design 

of the key and the selection of diagnostic characters. These 

weights, from five (relatively low) to nine (high), are given in 

the synoptic key following the feature description. For 

example, character 17 (ligule type) was given the relative 

weight of 8 and would be considered more taxonomically 

significant than a 7-weighted character and of less importance 

than a 9-weighted character. 

The DELTA program KEY was used as an experimental tool to 

automatically generate numerous key designs. After experimentation and analysis a final key design was selected that 

satisfied the authors’ concepts of character significance and 

placement of the genera, together with the program KEY 

requirements of mechanical efficiency and correctness. This 

character list was translated into Spanish for the production of 

the Spanish key. Finally, the keys were extensively edited to 

enhance the practical application of the couplets. 

The data were converted into INTKEY format for database 

interrogation and information retrieval. One of the numerous 

forms of information retrieval is exemplified by the synoptic 

key for the characters and genera. Initially, an alphabetic list in 

numeric order is given for the genera and is followed by an 

ordered sequence of 88 taxonomic characters. This character 

sequence is identical to that used in the descriptions. Each 

character consists of the feature description (e.g., plants, 

spikelets, etc.) followed by the character states used in this 

study. Each character state is followed by the numbers of 

genera exhibiting that state. The numbers correspond to those 

in the list of genera, For example, in character one (plant 

sexuality), monoecious genera include Blepharidachne (species 3) and Scleropogon (species 27). The synoptic key is 

especially useful for understanding the distribution of taxa for 

the character states. 

The description of the tribe was automatically generated by 

combining the data for all the recognized New World genera 

into a single description via INTKEY. In this description each 

character state is followed by a comment consisting of a whole 

number or a proportion that indicates the number of genera 

recorded for that state. For example, “plants hermaphroditic 

(30), dioecious (8)” indicates that 30 of the 38 genera are 

hermaphroditic, and eight of the 38 genera are dioecious. The 

statement “main axis glandular (4/37) or not glandular (34137)” 

indicates that four of 37 genera have a glandular main axis, 34 
NUMBER 87 3 

of 37 genera have a nonglandular main axis. Evidently, for one 

genus this character does not apply. From the synoptic key we 

find that the inflorescence of Monanthochloe consists of a 

single spikelet and is neither a raceme nor a panicle; that is, the 

main axis does not exist and the character is inapplicable. 

Generic descriptions were generated by CONFOR and then 

edited to enhance their aesthetic and scientific value. In these 

descriptions, characters are separated by semicolons, and 

commas are used where more than two character states apply. 

Additional information beyond that conveyed by the character 

list is treated as comments and is enclosed within parentheses. 

A period terminates a sequence of characters describing a 

primary feature. The descriptions are complete and are fully 

comparative. Any missing characters within a description are 

either data not applicable to the taxon or are information 

designated as implied. For example, if a genus lacks sterile 

florets then characters describing sterile florets will be 

inapplicable and will not occur in that description. Furthermore, character states designated as “implied” will not occur in 

the descriptions unless they are associated with additional 

information in the form of comments or other character states. 

Character states designated as implied are indicated within the 

synoptic key by an asterisk (*). An INTKEY analysis was 

performed to extract the diagnostic characters for each genus. 

The characters of this subset are underlined within each 

description. They are diagnostic in that the combination of 

these states is unique for the genus. For example, Allolepis is 

the only genus with the following subset of data: plants 

dioecious; ligule a ciliate membrane; florets 8-20 per spikelet; 

lemma 3-nerved. Selection of these characters by INTKEY was 

based on the identical parameters used in key production. 

Each description is followed by a paragraph containing four 

distribution characters, including the distribution by continent, 

distribution for the political regions of North American and 

Mesoamerica, distribution for the geopolitical regions of the 

continental United States, and distribution for the countries of 

South America. Finally, a character is given as to whether the 

genus is native or introduced to the New World. Information on 

each genus is terminated by a “Remarks” section, which 

presents comments on relationships among the genera and on 

character similarities. 

ACKNOWLEDGMENTS 

Financial support to visit the United States National 

Herbarium, Washington, D.C., was provided to JVR in the 

form of a Short-Term Visitor Grant from the Smithsonian 

Institution. We thank Dan Nicolson for correcting the Latin 

diagnosis and Vittoria Hess for technical support required for 

the special procedures. We also thank Stephan L. Hatch, Kelly 

W. Allred, Cheryl S. Roesel, and Surrey Jacobs for suggesting 

modifications that improved the manuscript. 

The Characters and Their Variation 

The purpose of this section is to present a discussion of the 

characters and character states applied in this study. Of the 88 

characters initially selected, 21 describe the habit, 17 describe 

the inflorescence, and, other than distribution and chromosome 

number, the remaining characters describe various structures of 

the spikelets (i.e,, general spikelet characters, glumes, rachilla, 

lemmas, paleas, and caryopses). 

Plant sexuality (character 1) was recorded as hermaphroditic 

for plants with all perfect spikelets, dioecious for separate male 

and female plants, monoecious for separate male and female 

spikelets on the same plant, gynomonoecious for plants with 

pistillate and perfect spikelets, or andromonoecious for plants 

with staminate and perfect spikelets. The most common state 

for this character is hermaphroditic. The taxonomic significance of this character is the presence of the dioecious state, 

which is diagnostic for Allolepis, Jouvea, Neeragrostis, 

Scleropogon, and Sohnsia. Scleropogon is the only genus 

recorded to be either dioecious or monoecious. There are no 

genera exclusively monoecious, gynomonoecious, or andromonoecious. An assessment of whether the genera are annual 

or perennial (character 2) was based on gross morphological 

features. This character has limited taxonomic significance due 

to the wide range of overlap among the genera. Bealia, Crypsis, 

Munroa, Neeragrostis, Neesiochloa, and Pereilema, however, 

are exclusively annual, and 21 taxa are exclusively perennial. 

This character does not appear in the diagnostic characters. 

Stoloniferous (character 3) was based on the presence or 

absence of sterile, above ground, and horizontal culms. This 

character also has limited taxonomic value at the generic level 

and does appear in the diagnostic characters. Presence or 

absence of rhizomes (character 4), or horizontal underground 

culms, is not a taxonomically significant character because it is 

not used in any of the diagnostic descriptions. Twenty-two 

genera may possess a rhizome and 22 may lack rhizomes. 

Sixteen genera are exclusively rhizomatous and 16 are not. Six 

genera (Allolepis, Eragrostis, Gouinia, Muhlenbergia, Sporobolus, and Tridens) are variable for this character. 

Flowering culm habit (character 5) was recorded in terms of 

erect, decumbent, or mat forming. A majority of the genera, 33, 

may be erect. None are exclusively decumbent, and only 

Monanthochloe is exclusively mat forming. This character does 

not appear in the diagnostic characters. Most of the genera may 

be caespitose (character 6); however, Blepharidachne, Crypsis, 

Monanthochloe, Munroa, Neeragrostis, and Pereilema are 

exclusively not caespitose. This character does not appear in 

the diagnostic characters. Flowering culms were recorded as 

either glabrous or hairy (character 7). A majority of the genera 

may be glabrous. Blepharidachne, Lycurus, Munroa, Sohnsia, 

and Swallenia are exclusively hairy. This character does not 

appear in the diagnostic characters. Type of hairs (character 8) 

associated with the flowering culms was recorded as pubescent 

for short scattered hairs, as pilose, or as villous. Of the 10 
4 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

genera that may be hairy, only Swallenia is not pubescent. This 

character is not taxonomically significant. Whether the internodes are viscid or glaucous was the ninth character applied in 

this study. Viscid internodes are found in Eragrostis, and 

glaucous internodes are found in Muhlenbergia; however, 

character overlap occurs for both genera. Therefore, this 

character has limited diagnostic value at the generic level. 

Whether the leaves are cauline or mostly basal (character 10) 

was also found to be highly variable. Thirty-one genera may 

have cauline leaves and 12 may possess mostly basal leaves. 

Genera recorded as exclusively with basal leaves include 

Dasyochloa, Erioneuron, Munroa, Reederochloa, Scleropogon, Sohnsia, and Tripogon. This character does not appear 

in the diagnostic characters. There is no overlap among the 

genera as to the presence of distinctly distichous leaves 

(character 11). This character appears in the diagnostic 

characters for Distichlis, Jouvea, and Monanthochloe, which 

are exclusively distichous. Character states for presence of leaf 

auricles (character 12) include the presence of sheath auricles, 

the presence of blade auricles, or the absence of auricles. The 

most common state is the absence of auricles, which occurs in 

36 of the 38 genera. Blade auricles are only found in Pereilema, 

whereas sheath auricles may be found in Bealia, Leptochloa, 

and Muhlenbergia but are exclusive only in Bealia. This 

character does not appear in the diagnostic characters; however, 

it is useful for distinguishing Bealia from Blepharoneuron. 

Relative length of the sheaths and culm internodes (character 

13) showed a high amount of overlap among the genera. This 

character has limited taxonomic value and does not appear in 

the diagnostic characters. Whether the sheaths are glandular or 

not (character 14) is particularly important for distinguishing 

Neeragrostis from all other genera except Eragrostis, for which 

this character is variable. Presence of a glandular sheath is one 

of the two diagnostic characters for Neeragrostis. Whether the 

sheath margins are smooth or scabrous (character 15) refers to 

the presence or absence of scabrosities on the margins. 

Character-state overlap exists among the genera for this 

character. Thus, it does not appear in the diagnostic characters 

and is relatively taxonomically insignificant for these genera. 

Presence or absence of a ciliate sheath (character 16) refers to 

the presence of the hairs on the sheath margins, especially 

toward the apex. Twenty-four genera are exclusively not ciliate, 

whereas eight are exclusively ciliate. Six genera are variable for 

this character, which was not selected for use in the diagnostic 

characters. 

One of the most important vegetative characters is the type of 

ligule (character 17), which is described in terms of a 

membrane, a ciliate membrane, a line of hairs, or absent. This 

character occurs in 12 of the diagnostic subsets of characters. 

The ligule in eight genera is exclusively a membrane, and in 

eight genera it is a ciliate membrane. The taxonomic 

significance between these two states is minimal. The ligule in 

16 genera is exclusively a line of hairs. No genera are recorded 

for both a membrane and a line of hairs; however, Eragrostis 

and Tridens are variable for ligule a ciliate membrane and 

ligule a line of hairs. Only Blepharidachne may lack a 

membrane. Shape of the leaf blades (character 18) was recorded 

in terms of filiform, linear, and triangular. The common 

recorded state was linear, which was present in 35 genera. 

Filiform leaves are found in seven genera but are exclusive only 

in Redfieldia. Triangular leaves are found in three genera but 

are exclusive only in Neeragrostis. This character is used in 

two subsets of diagnostic characters. Character states for shape 

of the leaf blades in cross section (character 19) include flat, 

conduplicate, involute, terete, and plicate. Plicate is only found 

in some species of Blepharidachne, whereas terete is only 

found in Sporobolus. Involute blades are found in 21 genera 

and are exclusively found in Calamoviljia, Dasyochloa, Jouvea, 

Redfleldia, Reederochloa, and Tripogon. Leaf blades conduplicate is exclusive in Erioneuron and Monanthochloe. The most 

common state is flat, which is found in 30 genera. This 

character was not used in the diagnostic characters, which is 

probably a result of the relatively low weight initially given the 

character. Leaf blades pungent or not (character 20) was 

determined by whether or not the tip or apex of the leaf blade 

was relatively hard and sharp pointed. The most common state 

was not pungent; however, pungent leaves were found in 12 

genera and were exclusive in nine of these. This character does 

not appear in the diagnostic characters. A determination was 

made as to whether the leaf margins were thickened or not 

thickened (character 21). The most common state is lacking 

thickened margins. Thickened margins are found in seven 

genera and are exclusive in six (Bealia, Dasyochloa, Erioneuron, Lycurus, Munroa, and Neesiochloa). Only Muhlen bergia 

is recorded as variable for this character, which does not appear 

in the diagnostic characters. 

Number of spikelets comprising the inflorescence (character 

22) was grouped into three character states. The most common 

state is an inflorescence of more than three spikelets, which 

occurs in 36 genera. An inflorescence of two or three (four) 

spikelets is characteristic of Jouvea and Reederochloa but is 

exclusive only in Reederochloa. An inflorescence consisting of 

a single spikelet occurs in Jouvea and Monanthochloe and is 

exclusive in Monanthochloe. This character appears in the 

diagnostic subset of characters and is important in defining the 

generic limits of Distichlis, Monanthochloe, and Reederochloa. 

Type of inflorescence (character 23) was either a raceme or a 

panicle. A true spike does not occur in this group. The most 

common state is a panicle, which is characteristic of 35 genera. 

A raceme occurs in Dasyochloa, Neesiochloa, Reederochloa, 

Scleropogon, and Tripogon but is exclusive only in Reederochloa and Tripogon. This character is used in the diagnostic 

subset for Chaboissaea, Eragrostis, Erioneuron, Leptochloa, 

and Tripogon. Whether the inflorescence was exserted, 

partially included, or fully included in the upper leaf sheath 

(character 24) was recorded. The most common state, filly 

exserted, is found in 35 genera. There is a high amount of 

overlap between exserted and partially included; however, 
NUMBER 87 5 

Dasyochloa and Monanthochloe are exclusively partially 

included in the upper sheath. Distichlis and Jouvea are exserted 

or fully included. Only Munroa is exclusively fully included. 

This character does not appear in the diagnostic characters. The 

main axis of the inflorescence was recorded as glands present 

or absent (character 25). The implied state is not glandular, 

which is found in 34 genera. A glandular main axis is found in 

four genera but is exclusive in Bealia, Neeragrostis, and 

Neesiochloa. This character does not occur in the diagnostic 

characters. Whether the main axis was smooth, scabrous, or 

hairy (character 26) also does not occur in the diagnostic subset 

of characters. Most of the genera are either smooth or scabrous. 

A hairy main axis may be found in six genera but is exclusive 

in Blepharidachne, Pereilema, and Sohnsia. 

Arrangement of primary branches on the main axis (character 27) was recorded as digitate or not digitate. The most 

common state is not digitate, which occurs in 35 genera. 

Digitate primary branches occur in Dactyloctenium and 

Eleusine. There is no overlap between these states. The degree 

of spreading of the primary branches (character 28) was 

recorded as appressed (an angle less than lo"), spreading (angle 

1O0-8Oo), divaricate (angle 8Oo-9Oo), or reflexed (angle greater 

than 90'). The typical states are appressed and spreading. Seven 

genera (Dactyloctenium, Eragrostis, Gouinia, Muhlenbergia, 

Redfieldia, Sporobolus, and Tridens) may be divaricate; 

however, only Redfieldia is exclusively divaricate. There are no 

genera with exclusively reflexed branches. This character does 

not occur in the diagnostic subset of characters. Whether the 

primary branches terminate in a spikelet or a bare point 

(character 29) is significant in defining Dactyloctenium, which 

is unique for exclusively possessing a naked point at the 

termination of the primary branches. One of the more important 

inflorescence characters is the degree of reduction in the 

primary branches (character 30). The character states include 

primary branches with appressed secondary branches or with 

spreading secondary branches and primary branches reduced to 

a fascicle of spikelets. Twenty-one genera may possess 

appressed secondary branches and 11 may have spreading 

secondary branches. Of these, seven (Bealia, Calamovilfa, 

Eragrostis, Muhlenbergia, Sporobolus, Uniola, and Vaseyochloa) are variable between these states. Three genera have 

the primary branches reduced to a fascicle of spikelets. Of 

these, Dasyochloa and Pereilema are exclusively reduced to a 

fascicle. This character appears in the diagnostic characters for 

Erioneuron, Leptochloa, and Tridens. 

Pedicels were recorded as glandular or not (character 3 1). 

The character state pedicels glandular is included in the 

diagnosis for Blepharoneuron. Not glandular is the implied 

state and may occur in 32 genera. Four genera may be 

glandular, but this state is exclusive for Bealia, Blepharoneuron, and Neesiochloa. The absence of this character in the 

diagnostic subset of characters for Bealia and Neesiochloa 

indicates that higher weighted characters were chosen over this 

character, which was initially given a relatively low weight of 

six. Presence of hair on the pedicels (character 32) also was 

given a relatively low reliability. Twenty-nine of the genera 

may be glabrous; of these, only three are variable. Of the six 

genera with hairy pedicels only Blepharidachne, Sohnsia, and 

Swallenia are exclusive for that state. Character states for hair 

type (character 33) include pubescent, pilose, and villous. 

Blepharidachne and Sohnsia are exclusively pubescent, Swallenia is exclusively pilose, and no genus is exclusively villous. 

Hair type has limited taxonomic significance at the generic 

level. Surface ornamentation of the pedicels (character 34) was 

recorded as smooth or scabrous. The genera are about equally 

divided between these states, and only four (Eragrostis, 

Muhlenbergia, Pereilema, and Tridens) are variable. This 

character has limited diagnostic value but is used in one couplet 

of the identification key as a secondary character to separate 

Erioneuron and Neesiochloa from Leptochloa and Trichoneura. 

Presence or absence of cleistogamous spikelets (character 

35) is used in the identification key but does not occur in the 

subset of diagnostic characters. Of the six genera recorded as 

possessing cleistogamous spikelets, only two (Steirachne and 

Triplasis) are exclusive for this state. One of the highest 

weighted characters is the point of disarticulation (character 

36). The two states are disarticulation above or below the 

glumes; the precise point is not defined. All of the genera 

except Uniola may have disarticulation above the glumes. 

Disarticulation below the glumes occurs in four genera but is 

variable in three (Cvpsis, Muhlenbergia, and Sporobolus). 

This character is used in two of the diagnostic descriptions. 

Whether disarticulation is at the base of the florets or within the 

florets (character 37) determines whether the lemma and palea 

disarticulate as a unit or disarticulate separately. Typically, the 

lemma and palea separate as a unit; however, in four genera 

(Crypsis, Eragrostis, Neeragrostis, and Neyraudia) the lemma 

and palea disarticulate separately. The latter two of these four 

are not variable. This character occurs in the diagnostic 

characters and is especially useful for separating Neyraudia 

from similar genera. 

The term callus is used to define a modification at the point 

of disarticulation. A hairy callus (character 38) may be found in 

15 genera and is exclusive in 12 of these. A glabrous callus is 

the typical state and may be found in 26 genera. Chaboissaea, 

Muhlenbergia, and Scleropogon are the only genera variable 

for this character, which occurs in five of the diagnostic subsets 

of characters. This character is especially useful for making the 

final separation between Neesiochloa and Tripogon, Triplasis 

from Leptochloa and Munroa, and Eragrostis and Redfieldia 

from similar ma. The only numeric character used in this study 

was spikelet length (character 39), which was divided into two 

artificial states (less than or equal to 4.9 mm long and greater 

than 4.9 mm long), resulting in minimal overlap among the 

genera. This character is used in the diagnostic characters of 

Calamovilfa, Jouvea, Leptochloa, and Scleropogon. Arrangement of spikelets (character 40) on the primary branch was 
6 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

described in terms of solitary, paired, or clustered. Lycurus is 

the only genus with paired spikelets. Spikelets may be in 

clusters in five genera but are exclusively clustered in four 

(Jouvea, Munroa, Neeragrostis, and Pereilema). Eragrostis is 

the only variable taxon for this character. The remaining 32 

genera are exclusively solitary. This character is especially 

useful for separating Jouvea and Scleropogon and for distinguishing Munroa from similar genera. Presence of sterile, 

bristle-like spikelets (character 41) is a unique characteristic of 

Pereilema; the remaining genera lack these structures. Spikelet 

compression (character 42) was recorded as laterally compressed, terete (for no compression), or dorsiventrally compressed. Thirty-two genera may be laterally compressed; 

however, five of these overlap with other states. Six genera are 

exclusively terete. Muhlenbergia is the only genus that 

overlaps all three character states. The terete state is especially 

useful for distinguishing Sporobolus from other genera with a 

I-nerved lemma (Calamovilfa and Cvpsis). Development of 

the pedicels (character 43) was recorded as sessile, subsessile 

(for pedicels less than 0.5 mm long), or pedicellate. Of the eight 

genera that lack pedicels, four (Dactyloctenium, Eleusine, 

Jouvea, and Monanthochloe) are exclusive for this state. 

Thirty-four genera are either subsessile or pedicellate, and a 

high degree of overlap exists between these states. This 

character was not in the diagnostic characters. 

Presence or absence of glumes (character 44) is only useful 

for separating Monanthochloe, which always lack glumes. 

Presence of glumes is the implied state and occurs in 37 genera. 

Jouvea and Munroa are variable for this character. The relative 

length of the glumes and spikelets (character 45) was separated 

into three states. Glumes shorter than the spikelets occurs in 30 

genera, and glumes about equal to the spikelets occurs in 13 

genera. Six genera overlap between these states. Only in Bealia 

and Muhlenbergia can the glumes exceed the spikelets. This 

character is especially useful for distinguishing between 

Leptochloa and Trichoneura. Relative length of the glumes 

(character 46) was defined by two states, unequal and more or 

less equal. The genera are about equally split between the 

states. Variable genera include Blepharoneuron, Eragrostis, 

Erioneuron, Muhlenbergia, Munroa, Pereilema, and Tridens. 

This character is especially useful for distinguishing Cvpsis 

from Calamovilfa and Sporobolus and distinguishing Chaboissaea from Leptochloa. Surface ornamentation of the glumes 

(character 47) was recorded as smooth or scabrous. This 

character has little or no diagnostic value at the generic level 

and does not appear in the diagnostic characters. The glumes of 

most of the genera are smooth, 11 may be scabrous, and eight 

are exclusively scabrous. Presence of hairs on the glumes 

(character 48) also does not appear in the diagnostic characters. 

Thirty-five may be glabrous and four may be hairy. Only 

Bealia and Lycurus are exclusively hairy. Number of nerves on 

the first glume (character 49) ranges from 0- to 8-nerved. Only 

Jouvea always lacks nerves on the first glume. A I-nerved first 

glume is the most common state and may occur in 30 genera. 

No genera are exclusively 2-, 3-, 4-, or 5-nerved. Reederochloa 

is the most variable genus, with 2-8-nerved first glumes. 

Swallenia is exclusively %nerved. This character is especially 

useful for separating Lycurus from Chaboissaea and Muhlenbergia. Relative length of the second glume to the lower lemma 

(character 50) was divided into three states. Four genera are 

recorded as having a second glume longer than the lemma, but 

only Dasyochloa is exclusive for this state. The typical 

morphology is for the second glume to be shorter than the 

lemma; however, they may be more or less equal in 15 genera 

This character was not used in the diagnostic characters. 

Whether the second glume was awned or unawned (character 

51) was not used in the diagnostic characters; however, this 

character was used as a secondary character in the identification 

key. The typical state is unawned, but nine genera may possess 

an awn, and six (Dactyloctenium, Dasyochloa, Lycurus, 

Neesiochloa, Pereilema, and Trichoneura) of these are exclusively awned. This character is useful for separating Neesiochloa from Tripogon and Erioneuron, Trichoneura from 

Leptochloa, and Dasyochloa from similar genera. Number of 

nerves on the second glume (character 52) ranges from one to 

1 1. Twenty-eight genera may be 1 -nerved, and five of these are 

variable. A 3-nerved second glume occurs in 10 genera and is 

exclusive in Allolepis. No genera are exclusively 5-, 7-, or 

%nerved. Swallenia and Vaseyochloa are characterized by a 

high number of nerves. This character has diagnostic value in 

separating Gouinia and Chaboissaea. 

Rachilla pronounced or not pronounced between the florets 

(character 53) was weighted as a taxonomically important 

character but was not selected in the analysis for diagnostic 

characters nor was it used in the identification key. The absence 

of a pronounced rachilla is implied and occurs in nine genera. 

Only two of these, Allolepis and Chaboissaea, overlap for the 

states. Rachilla hairy or glabrous (character 54) does appear in 

the diagnostic descriptions and key. No genera are variable for 

these states. A glabrous rachilla is the most common state. This 

character is useful for separating Neesiochloa and Steirachne 

from similar genera. The number of florets per spikelet 

(character 55) is one of the more taxonomically important 

characters. Of the nine genera characterized by a solitary floret, 

only Chaboissaea (with 1-3 florets) is variable. This character 

does not give a clear separation among the remaining 30 

genera. Five genera (Allolepis, Eragrostis, Jouvea, Neeragrostis, and Uniola) may have more than 20 florets. The highest 

number of florets is found in Eragrostis and Neeragrostis. This 

character is used in 22 of the diagnostic descriptions and is 

therefore the most significant character for defining New World 

generic concepts in this tribe. The presence or absence of sterile 

florets (character 56) was not used in the diagnostic descriptions. Sterile florets may be absent in eight genera and are 

always absent in six (Bealia, Blepharoneuron, Calamovilfa, 

Ctypsis, Muhlenbergia, and Sporobolus). Chaboissaea and 

Eragrostis are variable. This character is of secondary 

importance for distinguishing between Lycurus and Muhlen- 
NUMBER 87 

bergia. Location of the sterile florets (character 57) does not 

occur in the diagnostic description but is used in the 

identification key. Three genera (Blepharidachne, Neyraudia, 

and Tetrachne) only possess sterile florets below the fertile 

ones. Uniola is the only variable genus for this character. 

Whether the sterile florets are morphologically similar or 

dissimilar (character 58) was not selected as a diagnostic 

character; however, it is used in the key to separate Munroa 

from Sohnsia and Triplasis. Only Munroa and Pereilema are 

exclusively heteromorphic. 

Shape of the lemma apex (character 59) was defined with 

four states. Twenty-six genera may be entire, which is the most 

common state. Of these, only Leptochloa and Muhlenbergia 

overlap. Eleven genera may be emarginate or lobed. The most 

taxonomically important state is cleft, which is exclusive for 

Blepharidachne, Neyraudia, and Sohnsia and which can be 

used to separate these from morphologically similar genera. 

This character occurs in numerous diagnostic descriptions. 

Presence of an apical appendage (character 60) was defined in 

terms of awned, mucronate, and unawned. Fourteen genera are 

exclusively awned, and 17 genera are either mucronate or 

unawned. This character is particularly valuable for separating 

Bealia from Blepharoneuron. Presence of hairs on the lemma 

(character 61) was not used in the diagnosis, and the genera are 

evenly divided between the states. Type of hairs on the lemma 

(character 62) include pubescent, pilose, and villous. This 

character has limited diagnostic value; however, Erioneuron 

and Sohnsia are exclusively pilose, and Bealia, Blepharidachne, Blepharoneuron, Dasyochloa, Neyraudia, Swallenia, 

and Triplasis are exclusively villous. Surface ornamentation of 

the lemma (character 63) was described as smooth or scabrous. 

This character has little diagnostic value at the generic level and 

does not appear in the diagnostic subset of characters. Most of 

the taxa are smooth, but 11 are exclusively scabrous. Number 

of nerves on the lemma (character 64) varies from 1- to 

13-nerved. Three genera (Calamovilfa, Crypsis, and Sporobolus) are 1-nerved and do not vary. Genera with many-nerved 

lemmas include Distichlis, Monanthochloe, Reederochloa, 

Uniola, and Vaseyochloa. The remaining genera are 3-5- 

nerved. This character is used extensively in the diagnostic 

descriptions. Texture of the lemma (character 65) varies from 

hyaline to indurate. Neeragrostis is the only genus exclusively 

with a hyaline lemma. This state is shared with four genera that 

overlap with state lemma membranous. Exclusively densetextured lemmas are characteristic of Allolepis, Distichlis, 

Monanthochloe, Reederochloa, and Scleropogon. This character is useful for the final separation of Chaboissaea from Bealia 

and Blepharoneuron. Whether the lemma nerves are glabrous 

or hairy (character 66) has little diagnostic value. Genera that 

are variable for the states of this character include Calamovi&ia, 

Leptochloa, Muhlenbergia, and Sohnsia. Whether the palea is 

hairy or glabrous (character 67) is valuable for making the final 

separation of Dasyochloa from Munroa and Neyraudia. The 

typical state for the presence or absence of an awned palea 

(character 68) is unawned. Only three genera (Chaboissaea, 

Gouinia, and Muhlenbergia) may possess an awned palea. This 

character is specifically valuable for making the final separation of Gouinia from Eleusine, Leptochloa, and Tridens. 

Texture of the palea (character 69) varies from hyaline to 

indurate. Cvpsis and Neeragrostis are exclusively hyaline. The 

most common states are membranous and chartaceous, which 

are found in 34 taxa. Genera with relatively dense-textured 

paleas are Allolepis and Monanthochloe. Recording data for 

whether or not the palea margins enfold the hit (character 70) 

tended to be subjective, and the distinction between the states 

was obscure. As a result, the character was initially given a low 

weight and thus was not used in the key and diagnostic 

descriptions. At present, 1 1 genera are coded as palea enfolding 

the hit and the others are coded as the alternative, with no 

overlap between the states. Additional studies are needed to 

precisely define the differences between the states of this 

character. Whether the palea keels are ciliate or not (character 

71) does not appear in the diagnostic characters but is used as 

a secondary character in the key. A ciliate palea occurs in 11 

genera but is exclusive for nine genera. Eragrostis and Gouinia 

are the only variable taxa. Surface Ornamentation of the palea 

(character 72) was recorded as smooth or scabrous. The 

character has limited taxonomic significance at the generic 

level and was not used in the key or the diagnostic characters. 

Those genera recorded as always scabrous are Chaboissaea, 

Eleusine, Gouinia, Lycurus, Pereilema, and Steirachne. 

Presence or absence of lodicules (character 73) was given a 

relatively low weight due to the difficulty in correctly making 

the interpretation. The common or typical condition is for the 

lodicules to be present, which occurs in 35 genera. It appears to 

be always absent in Blepharidachne, Crypsis, and Monanthochloe. Variable genera are Munroa, Scleropogon, and 

Sporobolus. Whether or not the lodicules are adnate to the palea 

(character 74) also was given a relatively low weight. Only two 

genera (Erioneuron and Tridens) are recorded as adnate, and 

there are no variable genera for this character. Shape of the 

lodicule apex (character 75) also was low weighted and was not 

used as a diagnostic character. The most common state is 

truncate, which occurs in 25 genera. At present, data for this 

character are suspect. 

Number of stamens (character 76) varies between one and 

three. No genus exclusively has only one stamen. One or three 

stamens are found in Erioneuron, and one to three stamens are 

found in Tripogon. Only Steirachne is recorded as exclusively 

possessing two stamens. Three stamens occur in 37 genera. 

Anther color (character 77) was grouped into three states 

(yellow, reddish purple, and olivaceous plumbeous). Twentyfour genera are coded as yellow, and of these, 16 are 

exclusively yellow. Twenty were considered to be reddish 

purple. Six genera (Eragrostis, Jouvea, Leptochloa, Lycurus, 

Redfieldia, and Tetrachne) are variable between these states. 

Neesiochloa and Reederochloa are exclusively olivaceous 
8 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

plumbeous. Because the distinction between these states can be 

somewhat subjective, the character was given a relatively low 

weight and was not used in the identification key or diagnostic 

characters. Number of stigmas (character 78) is consistently 

two for all genera except Munroa, which varies between two 

or three stigmas. Whether the pericarp is free or adnate 

(character 79) to the fruit was weighted relatively high. 

Thirty-one taxa possess the implied state of an adnate pericarp. 

A free pericarp is found in seven genera and no taxa vary 

between these states. This character is useful for separating 

Eleusine from other genera with a ciliate membrane ligule and 

for separating Terrachne from genera with a similar ligule and 

overlapping number of florets per spikelet. Compression of the 

caryopsis (character 80) was not considered to be a highly 

reliable character. The typical condition is terete, which is 

characteristic of 27 genera. Exclusively dorsiventrally compressed caryopses are found in Munroa, Neesiochloa, Trichoneura, Tridens, and Triplasis, whereas the caryopsis in 

Blepharidachne, Pereilema, and Reederochloa is exclusively 

laterally compressed. Presence of persistent style bases 

(character 8 1) was high weighted. The typical condition is for 

persistent style bases to be absent. The presence of these 

persistent bases is diagnostic of Swallenia and Vaseyochloa, 

which may be then separated on shape of the base (character 

82). A short and blunt base is characteristic of Swallenia, and a 

sharp-pointed base is characteristic of Vaseyochloa. Base 

chromosome number (character 83) for this tribe is typically 

eight, nine, or 10. A base number of seven is found in 

Blepharidachne and Munroa, but the latter may have a base 

number of eight. 

Distribution was described under four characters (distribution by continent (character 84), in North America and 

Mesoamerica (character SS), in regions of the United States 

(character 86), and in South America (character 87)). Specific 

data on these characters are discussed following each generic 

description. 

Key to the Eragrostideae of the New World 

Florets 1 per spikelet .............................. 2 

Florets 2 or more per spikelet ......................... 12 

Lemma 1-nerved; ligule a line of hairs or absent; fruit with free pericarp ... 3 

Lemma 3-nerved or more; ligule a membrane or a ciliate membrane; fruit with 

adnate pericarp ................................ 5 

Spikelets 2 5-10 mm long; lemma chartaceous; callus hairy; palea hairy .... 

Spikelets up to 4.9 mm long; lemma hyaline to membranous; callus glabrous; 

Glumes very unequal; spikelets usually terete; glumes smooth ......... ................................. 29. Sporobolus 

Glumes more or less equal; spikelets strongly laterally compressed; glumes 

scabrous. ............................. .7. Crypsis 

Spikelets subtended by sterile bristles and in small clusters; blade auricles 

prominent and usually ciliate .................. 24. Pereilema 

Spikelets not subtended by sterile bristles and occurring solitarily or in pairs; 

blade auricles absent ............................. 6 

Lemma apex emarginate to lobed ....................... 11 

................................. 5. Calamovilfa 

palea glabrous ................................ .4 

Lemma apex entire. .............................. 7 

First glume 1-nerved and occasionally I-awned ................ 8 

First glume 2- or 3-nerved and 2(-3)-awned ................. 10 

Lemma with densely appressed to spreading silky, whitish hairs on midnerve 

and margins, hairs often appearing as ridges on surface at x20; pedicels 

minutely glandular, capillary, wiry, and flexuous, usually nodding and 

reflexed; paleas densely silky villous between nerves ............. .............................. ,4. Blepharoneuron 

Lemma glabrous or with appressed to spreading hairs on midnerve and margins 

but without silky, whitish hairs appearing as ridges on surface at x20; pedicels 

not minutely glandular, appressed or spreading, occasionally capillary to 

nodding and reflexed; paleas glabrous or with appressed to spreading hairs 

between nerves. ............................... 9 
NUMBER 87 9 

lO(7). 

1 l(6). 

12( 1). 

13(12). 

14(12). 

15(14). 

16(15). 

17(16). 

18( 15). 

Spikelets with 1,2, or occasionally 3 florets, lowermost perfect, upper pedicelled 

florets usually staminate, reduced, and/or sterile; lemma chartaceous and 

Spikelets with 1 floret, or when occasionally 2-3-flowered, upper floret fertile; 

lemma hyaline or membranous, rarely chartaceous, plumbeous or mottled . . 

Spikelets paired; sterile florets present, lower spikelet with floret short 

pedicellate, usually staminate, occasionally sterile or perfect, upper spikelet 

with floret usually long pedicellate and perfect; inflorescence a spiciform 

Spikelets solitary or paired; sterile florets absent; inflorescence a contracted 

Lemma apex deeply bilobed, lobes 1-1.4 mm long, rounded to obtuse; awn 

crisped-curled to flexuous, borne between lobes; pedicels minutely glandular; 

Lemma apex not deeply bilobed (except in perennials Muhlenbergia argentea 

and M. lucidu), sometimes emarginate to shallowly lobed, teeth C 1 mm long, 

usually acuminate to aristate; awn straight to flexuous; pedicels not glandular; 

wide ranging in North and South America to Southeast Asia ......... 

Caryopsis with persistent styles bases ..................... 13 

Ligule a membrane or a ciliate membrane; caryopsis with pronounced 

sharp-pointed style bases, deeply concave on ventral side; leaf blades not 

Ligule a line of hairs; caryopsis with relatively short and blunt style bases, not 

deeply concave on ventral side; leaf blades pungent; glumes more or less equal 

................................. .31. Swallenia 

Inflorescence a raceme with stalked or pedicelled spikelets placed along central 

axis ...................................... 15 

Inflorescence a panicle with at least primary branches, these rebranched, or 

primary branches often racemosely inserted along elongated central axis or 

digitately arranged from central point. ................... 19 

Second glume 1 -nerved; plants hermaphroditic; lemma emarginate, lobed, or 

Second glume 3-8-nervedY nerves often indistinct; plants dioecious or 

monoecious; lemma entire; lemma coriaceous ............... 18 

Ligule a line of hairs; palea extending into awns; leaf blades pungent; plants 

Ligule a ciliate membrane; palea not extending into awns; leaf blades not 

Lemmas oblate (much wider than long) to fan-shaped, apex truncate; spikelets 

3-5.5 mm wide; glumes more or less equal; second glume awned; rachilla 

Lemmas elliptic to ovate-lanceolate, apex acute; spikelets < 1.5 mm wide; 

glumes very unequal; second glume unawned; rachilla glabrous ....... 

Lemmas of pistillate spikelets unawned; ligule a membrane; staminate culms 

3- 1 1 cm tall; sheaths ciliate; leaf blades tightly involute; glumes very unequal 

............................... .26. Reederochloa 

Lemmas of pistillate spikelets with 3 terminal awns 3-15 cm long; ligule a line 

of hairs; culms mostly 10-25 cm tall; sheaths not ciliate; leaf blades flat or 

conduplicate; glumes more or less equal .......... 27. Scleropogon 

plumbeous to grayish yellow, mottled ............ 6. Chabohsaea 

............................... 19. Muhlenbergia 

panicle, branches < 0.6 cm long ................. 17. Lycurus 

panicle, branches 1-3.7 cm long ............. 19. Muhlenbergia 

single annual species in Chihuahua and Durango, Mexico ..... 2. Bealia 

............................... 19. Muhlenbergia 

Caryopsis lacking persistent style bases .................... 14 

pungent; glumes very unequal ............... .38. Vaseyochloa 

cleft; lemma membranous .......................... 16 

stoloniferous .......................... 9. Dasyochloa 

pungent; plants lacking stolons ....................... 17 

hairy ............................. 22. Neesiochloa 

.................................. 36. Tripogon 
10 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

19( 14). Disarticulation below glumes, spikelets falling entire; lemmas strongly keeled, 

coriaceous, 3-9-nerved; lower 2-6 florets of each spikelet sterile ...... ................................... 37. Uniola 

Disarticulation above glumes, spikelets not falling entire; lemmas not strongly 

keeled, or if keeled then hyaline, membranous, or chartaceous, usually 

3-nerved; lower florets of each spikelet usually fertile ........... 20 

20(19). Lemma and palea usually disarticulating separately; keels of palea usually 

ciliolate; palea longitudinally bowed out ........... 12. Eragrostis 

Plants lacking above combination of character states ............ 21 

21(20). Ligule a membrane or a ciliate membrane .................. 22 

Ligule a line of hairs or absent ........................ 39 

22(21). Lemma entire. ................................ 23 

Lemma emarginate, lobed, or cleft ...................... 33 

23(22). Fruit with free pericarp; inflorescence with primary branches digitate or of 

I-sided racemes loosely spaced along central axis ............. 24 

Fruit with adnate pericarp; inflorescence with primary branches not digitate or 

of l-sided racemes along central axis ................... .26 

24(23). Inflorescence with 6-16 racemosely arranged primary branches; sterile florets 

present below fertile ones ................... 32. Teachne 

Inflorescence with 1-1 7 digitately or subdigitately arranged primary branches; 

sterile florets present above fertile ones ................... 25 

25(24). Second glume l-nerved and awned; primary branches terminating in a bare 

point; plants often stoloniferous .............. 8. Dactyloctenium 

Second glume 3-5-nerved and unawned; primary branches terminating in a 

spikelet; plants lacking stolons ................. 11. Eleusine 

Leaves not distinctly distichous; leaf blades not pungent .......... 28 

27(26). Inflorescence consisting of a solitary spikelet borne in mils of fascicled leaves; 

leaf blades 0.5- 1.5 cm long, conduplicate and subulate; glumes absent; plants 

stoloniferous; spikelets sessile .............. 18. Monanthochloe 

Inflorescence normally consisting > 3 spikelets borne on exserted to partially 

included axis without fascicled leaves; leaf blades 2-8 cm long, flat or 

involute, linear; glumes present; plants usually lacking stolons; spikelets 

pedicellate ............................ 10. Distichlis 

28(26). Plants hermaphroditic ............................. 29 

Plants dioecious or andromonoecious ..................... 32 

29(28). Spikelets < 5 mm long ............................ 30 

Spikelets 2 5 mm long ............................ 31 

30(29). Glumes very unequal; inflorescence with racemose primary branches along 

elongated central triquetrous main axis; lemma membranous, greenish to 

26(23). Leaves distinctly distichous; leaf blades pungent ............... 27 

stramineous, not mottled; palea membranous and smooth ........... ................................. 16. Leptochloa 

Glumes more or less equal; inflorescence with distant, alternate, rebranched 

primary branches, secondary branches usually strongly appressed; lemma 

chartaceous and plumbeous to grayish yellow, mottled; palea chartaceous and 

scabrous ............................ 6. Chaboissaea 

31(29). Lemmas awned, awns 5-20 mm long; callus hairy; sheaths with scabrous 

margins; glumes and palea scabrous ............... 14. Gouinia 

Lemmas unawned or with awns < 3.5 mm long; callus glabrous; sheaths with 

smooth margins; glumes and palea smooth .......... 16. Leptochloa 
NUMBER 87 11 

32(28). Spikelets 1.8-4.7 mm long; second glume l-nerved; plants lacking stolons; 

spikelets laterally compressed, usually with 2, or occasionally 3, florets, 

lowermost perfect, upper pedicellate florets usually staminate, reduced, and/or 

................................. 6. Chaboissaea 

Spikelets 9-25 mm long; second glume 2-nerved or more; plants stoloniferous; 

spikelets terete or dorsiventrally compressed, with 6-20 florets, upper ones 

often sterile; lemma coriaceous and stramineous or lustrous, not mottled ... ................................... 1. Allolepis 

33(22). Sterile florets reduced, sterile florets below fertile floret; spikelets always 

4-flowered, 2 sterile, 1 fertile, 1 reduced; fertile lemma 3-awned; pedicels 

hairy; lodicules absent , , . . , . . , , . , , . , , , . , 3. Blepharidachne 

Sterile florets only above fertile florets; spikelets usually > (2-)4-20-flowered; 

fertile lemma usually l-awned; pedicels glabrous; lodicules present .... 34 

34(33). Lemma awned. ............................... .35 

Lemma unawned or mucronate ....................... .38 

35(34). Callus hairy; palea ciliate; leaf blades with thickened margins; pedicels smooth 

........................................ 36 

Callus glabrous; palea not ciliate; leaf blades without thickened margins; 

pedicels scabrous .............................. 37 

36(35). Lemmas ovate to lanceolate, apex acute to obtuse; second glume unawned; 

rachilla glabrous; primary branches with appressed secondary branches; 

pedicels < 4 mm long ..................... 13. Erioneuron 

Lemmas oblate (much wider than long) to fan-shaped, apex truncate; second 

glume awned; rachilla hairy; primary branches with spreading secondary 

37(35). Glumes shorter than spikelet, very unequal, smooth; second glume unawned; 

rachilla completely glabrous; lateral nerves of lemma not ciliate, often 

pubescent, hairs < 0.6 mm long ................ 16. Leptochloa 

Glumes about equaling spikelet, more or less equal, scabrous; second glume 

awned; rachilla with a tuft of hairs at summit; lateral nerves of lemma 

long-ciliate, hairs 1-3 mm long ............... 33. Trichoneura 

38(34). Inflorescence with racemose primary branches along elongated central 

triquetrous rachis, spikelets mostly appressed; lemmas mostly glabrous to 

puberulent along nerves below ................ 16. Leptochloa 

Inflorescence with paniculate primary branches with mostly spreading 

................................... 34. Tridens 

39(21). Lemma entire. ................................ 40 

40(39). Plants hermaphroditic ............................. 41 

Plants dioecious or monoecious ....................... .43 

4 l(40). Sterile florets below fertile florets; inflorescence with racemose primary 

branches separated by about their own length along central axis; plants 

introduced to New World ................... 32. Teirachne 

Sterile florets above fertile florets; inflorescence with paniculate primary 

branches; plants native to New World ................... 42 

42(41). Callus glabrous; glumes more or less equal in length; cleistogamous spikelets 

near base or upper leaf ails; spikelets 6- 13-flowered; lemma membranous; 

keels of palea bowed out, finely ciliate-scabrid ........ 30. Steirachne 

sterile; lemma chartaceous and plumbeous to grayish yellow, mottled .... 

branches; pedicels 5-20 mm long .............. 22. Neesiochloa 

secondary branches; lemmas mostly short hairy along nerves below ..... 

Lemma emarginate, lobed, or cleft ...................... 45 
12 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Callus hairy; glumes very unequal in length; cleistogamous spikelets absent; 

spikelets I-6-flowered; lemma chartaceous; keels of palea not bowed out, 

glabrous ............................ 25. Redfieldia 

43(40). Disarticulation with lemma and palea falling separately; leaf blades not pungent; 

plants annual; sheaths glandular; plants lacking stolons; lemma hyaline; 

staminate florets with ciliolate palea keels; pistillate florets with palea < l/2 

length of lemma ....................... 21. Neeragrostis 

Disarticulation with lemma and palea falling as unit; leaf blades pungent; plants 

perennial; sheaths not glandular; plants stoloniferous; lemma chartaceous to 

coriaceous; staminate florets without ciliolate palea keels; pistillate florets 

44(43). Pistillate spikelets 8-30 mm long; lemmas of pistillate spikelets unawned; 

second glume l-nerved; pistillate spikelets in clusters in axils of leaves; 

spikelets sessile .......................... 15. Jouvea 

Pistillate spikelets 20-40 mm long; lemmas of pistillate spikelets with 3 

terminal awns 3-15 cm long; second glume 3-5-nerved; pistillate spikelets 

solitary, usually exserted; spikelets pedicellate ....... 27. Scleropogon 

45(39). Tall, reed-like, culms 1-3 m tall, panicles plumose; lemma margins villous near 

base, hairs 3-5 mm long; sterile florets below fertile florets; disarticulation 

with lemma and palea falling separately; introduced to New World ..... ................................. 23. Neyraudia 

Short caespitose to taller but not reed-like, culms 0.4-1.7 m tall, panicles not 

plumose; lemmas ciliate near base, hairs usually < 3 mm long; sterile florets 

above fertile florets; disarticulation with lemma and palea falling as unit; 

native to New World ............................ 46 

46(45). Lemma unawned or mucronate, with apex entire or emarginate; culms 20-170 

cm tall, erect ........................... 34. Tridens 

Lemma with awns 2 1.5 mm long, with apex emarginate, lobed, or cleft, if 

emarginate then plants decumbent, with culms not more than 15 cm tall; culms 

47(46). Palea extending into awns; second glume awned; second glume longer than 

Palea not extending into awns; second glume unawned; second glume shorter 

than lower lemma to about same length as lower lemma; palea glabrous on 

margins ................................... 48 

48(47). Leaf blades pungent; plants stoloniferous, bearing fascicles of leaves; spikelets 

in capitate clusters of 2-4, partially hidden in fascicles of leaves at branch tips; 

sterile florets heteromorphic ................... 20. Munroa 

Leaf blades not pungent; plants lacking stolons and fascicles of leaves; spikelets 

49(48). Plants hermaphroditic; pistillate lemmas l-awned, awns up to 2.5 mm long; 

glumes very unequal in length; cleistogamous spikelets present in upper and 

Plants dioecious; pistillate lemmas 3-awned, awns up to 6 mm long; glumes 

more or less equal in length; cleistogamous spikelets absent . . 28. Sohnsia 

with palea about as long as lemma ..................... 44 

4-100 cm tall, decumbent, mat forming, or erect ............. 47 

lower lemma; palea ciliate on margins ............ 9. Dasyochloa 

solitary, exserted; sterile florets homomorphic ............... 49 

lower sheaths ........................... 35. Triplasis 

Clave para Eragrostideae del Nuevo Mundo 

1. Flosculos 1 por espiguilla ............................ 2 

Flosculos 2 o mas por espiguilla ....................... 12 

2(1). Lema l-nervada; ligula una fmbra de pelos o ausente; fruto con el pericarpio 

libre ...................................... 3 

Lema con 3 o mas nervios; ligula una membrana o una membrana ciliada; fruto 

con el pericarpio soldado. ......................... .5 
NUMBER 87 13 

lO(7). 

1 l(6). 

12( 1). 

13(12). 

Espiguillas 5-10 mm o mas de longitud; lema cartacea; callo piloso; palea pilosa 

Espiguillas hasta 4.9 mm de longitud; lema hialina a membranosa; callo glabro; 

................................. 5. Calamovilfa 

paleaglabra.. ............................... -4 

Glumas desiguales; espiguillas rollizas; glumas lisas ...... 29. Sporobolus 

Glumas casi iguales; espiguillas marcadamente cornprimidas lateralmente; 

glumas escabrosas .......................... 7. Cypsz% 

Espiguillas con cerdas esteriles subyacentes y presentandose agrupadas; hojas 

con auriculas en el limbo prominetes y usualmente ciliadas .......... ................................. .24. Pereilema 

Espiguillas sin cerdas esteriles subyacentes y presentandose solitarias o en pares; 

hojas sin auriculas .............................. 6 

Lemaentera. ................................. .7 

Lema emarginada o lobada .......................... 11 

Primera gluma 1-nervada y ocasionalmente con una arista .......... 8 

Primera gluma con 2(-3) nervios y 2(-3) aristas ............... 10 

Lema con pelos densamente apresados o extendidos, sedosos y blanquecinos 

sobre el nervio central y margenes, 10s pelos presentandose acanalados sobre 

la superficie a x20; pedicelos con glandulas diminutas, capillares, flexuosos, 

usualmente colgantes y reflexos; paleas densamente sedoso villosas entre 10s 

nervios .......................... .4. Blepharoneuron 

Lema glabra o con pelos apresados o extendidos sobre el nervio central y 

margenes per0 sin presentarse sedosos y blanquecinos, ni acanalados sobre la 

superficie a x20; pedicelos sin glandulas diminutas, apresados o extendidos, 

ocasionalmente capilares o colgantes y reflexos; paleas glabras o con pelos 

Espiguillas con 1,2, ocasionalmente 3 flosculos, con el mas inferior perfecto, 10s 

flosculos superiores usualmente estaminados, reducidos, y/o esteriles; lema 

cartacea y moteada de color gris hasta verde amarillo .... 6. Chaboissaea 

Espiguillas con 1 flosculo, o cuando ocasionalmente es 2-3-floscular, el 

superior es fertil; lema hialina o membranosa, raramente cartacea y moteada de 

color gris .......................... 19. Muhlenbergia 

Espiguillas en pares; flosculos esteriles presentes, la espiguilla inferior con un 

flosculo corto pedicelado, usualmente estaminado, ocasionalmente esteril o 

perfecto, la espiguilla superior con un flosculo usualmente largo pedicelado y 

perfecto; inflorescencia una panicula espicifome, con las ramificaciones 

menores de 0.6 cm de longitud .................. 17. Lycurus 

Espiguillas solitarias o en pares; flosculos esteriles ausentes; inflorescencia una 

panicula contraida, las ramificaciones 1-3.7 cm de longitud ......... ............................... 19. Muhlenbergia 

Lema profundamente bilobada, 10s lobulos 1 - 1.4 mm de longitud, redondeados 

a obtusos; arista curvada a flexuosa, naciendo entre 10s lobulos; pedicelos con 

glandulas diminutas; una sola especie anual de Chihuahua y Durango, Mexico 

.................................... 2. Bealia 

Lema no profundamente bilobada (except0 en las perennes Muhlenbergia 

argentea y M. lucida), algunas veces emarginada a levemente lobada, con 10s 

lobulos menores de 1 mm long, y usualmente acuminado o aristados; arista 

recta o flexuosa; pedicelos sin glandulas; con amplia distribucion en Norte y 

Sur America hasta el sureste de Asia ........... 19. Muhlenbergia 

Cariopsis con las bases del estilo persistentes ................. 13 

Cariopsis con las bases del estilo no persistentes ............... 14 

Ligula una membrana o una membrana ciliada; cariopsis con la bases del estilo 

pronunciadas en puntas, marcadamente concavas en la cara ventral; limbos 

con apice no punzante; glumas desiguales .......... 38. Vmeyochloa 

adpresos a ascendentes entre 10s nervios ................... 9 
14 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

14(12). 

15(14). 

16( 15). 

17( 16). 

18(15). 

19(14). 

20(19). 

2 l(20). 

22(21). 

23 (22). 

24(23). 

25(24). 

Ligula una fiibra de pelos; caryopsis con las bases del estilo relativamente 

cortas y obtusas, no marcadamente concavas en la cam ventral; limbos con 

apice punzante; glumas casi siguales .............. 31. Swallenia 

Inflorescencia un racimo con espiguillas pediceladas a lo largo del eje central 

........................................ 15 

Inflorescencia una panicula con las ramificaciones primarias ramificadas o con 

las ramificaciones primarias racemosas o espigadas o digitadas . , . , . . 19 

Segunda gluma l-nervada; plantas hermafioditas; lema emarginada, lobada, o 

partida; lema membranosa ......................... 16 

Segunda gluma 3-8-nervada, 10s nervios a menudo indistintos; plantas dioicas 

o monoicas; lema entera; lema coriacea .................. 18 

Ligula una fiibra de pelos; palea con 10s nervios pronunciados en aristas; limbo 

con apice punzante; plantas estoloniferas ........... 9. Dasyochloa 

Ligula una membrana cilia&, palea con 10s nervios no pronunciados en aristas; 

limbos con apice no punzante; plantas sin estolones ............ 17 

Lemas oblatas (mas anchas que largo) a forma de abanico, apice truncado; 

espiguillas 3-5.5 mm ancho; glumas casi iguales; segunda gluma aristada; 

raquilla pilosa ......................... 22. Neesiochloa 

Lemas elipticas a ovado-lanceoladas, apice agudo; espiguilla menores de 1.5 

36. Tripogon 

Lemas de espiguillas pistiladas sin arista; ligula una membrana; culmos 

staminados 3-1 1 cm altura; vainas ciliadas; limbos marcadamente involutos; 

glumas desiguales ...................... 26. Reederochloa 

Lemas de espiguilla pistiladas con 3 aristas terminales de 3-15 cm long; ligula 

una fimbra de pelos; culmos usualmente 10-25 cm altura; vainas no ciliadas; 

Desarticulacion debajo de las glumas, las espiguillas cayendo enteras; lema 

marcadamente aquilladas, coriaceas, 3-9-nervada; flosculos inferiores 2-6 de 

cada espiguilla esteriles ...................... 37. Uniola 

Desarticulacion arriba de las glumas, las espiguillas no cayendo enteras; lema no 

marcadamente aquilladas o si aquilladas, entonces hialinas, membranosas, o 

cartaceas, usualmente con 3 nervios; flosculos inferiores de cada espiguilla 

usualmente fertiles. ............................ .20 

Lema y palea usualmente desarticulando separadamente; quillas de la palea 

usualmente cilioladas; palea curvada longitudinalmente .... 12. Eragrostis 

Plantas sin la combinacion de caracteres citados arriba ........... 21 

Ligula una membrana o una membrana ciliada ............... ,22 

Ligulaunafimbradepelos o ausente. .................... 39 

Lema emarginada, lobada, o partida ..................... 33 

con racimos unilaterales laxamente dispuestos a lo largo del eje central ... 

digitadas ni con racimos unilaterales a lo largo del eje central ....... 26 

esteriles presentes debajo de 10s fertiles ............ 32. Tetrachne 

mente; flosculos esteriles presentes arriba de 10s fertiles .......... 25 

mm ancho; glumas desiguales; segunda gluma sin arista; raquilla glabra ... .................................. 

limbos planos o conduplicados; glumas casi iguale ..... 27. Scleropogon 

Lema entera. ................................ .23 

Fruto con el pericarpio libre; inflorescencia con las ramas primarias digitadas o 

........................................ 24 

Fruto con el pericarpio soldado; inflorescencia con las ramas primarias no 

Inflorescencia con 6- 16 ramas primarias dispuestas racemosamente; flosculos 

Inflorescencia con 1 - 17 ramas primarias dispuestas digitada o subdigitadaSegunda gluma l-nervada y aristak, inflorescencia con las ramificaciones 

primarias terminando en un punto desnudo; plantas a menudo estoloniferas 

............................... 8. Dactyloctenium 
NUMBER 87 15 

26(23). 

27(26). 

28(26). 

29(28). 

30(29). 

3 1 (29). 

32(28). 

33(22). 

34(33). 

35(34). 

36(35). 

Segunda gluma 3-5-nervada y sin arista; inflorescencia con las ramificaciones 

primarias terminando en ma espiguilla; plantas no estoloniferas ....... .................................. .11. Eleusine 

Hojas claramente disticas; limbos con apice punzante ............ 27 

Hojas no claramente disticas; limbos con apice no punzante ........ .28 

Inflorescencia consistiendo de una sola espiguilla, presentandose solitaria en las 

axilas de limbos fasciculados; limbos 0.5-1.5 cm de longitud, conduplicados 

y subulados; glumas ausentes; plantas estoloniferas; espiguillas sesiles .... .............................. .18.Monanthochloe 

Inflorescencia consistiendo de mas de 3 espiguillas, presentandose sobre un eje 

exerto o parcialmente incluido, sin limbos fasciculados; limbos 2-8 cm de 

longitud, lineares, planos o involutos; glumas presentes; plantas usualmente 

no estoloniferas; espiguillas pediceladas ............ 10. Distichlis 

Plantas hermafroditas ............................ .29 

Plantas dioicas o andromonoicas ....................... 32 

Espiguillas hasta 4.9 mm de longitud ..................... 30 

Glumas desiguales; inflorescencia con ramificaciones primarias racemosas; 

lema membranosa, de color verde o paja; palea membranosa y lisa ...... 

Glumas casi iguales; inflorescencia con ramificaciones primarias ramificadas, 

alternas, distantes, ramificaciones secundarias usualmente apresadas; lema 

cartacea, de color gris o amarillo grisaceo; palea cartacea y escabrosa .... ................................. 6. Chaboissaea 

Lemas con aristas 5-20 mm long; callo piloso; vainas con margenes escabrosos; 

glumas y paleas escabrosas .................... 14. Gouinia 

Lemas mucronadas o muticas, aristas hasta 3.5 mm long; callo glabro; vainas 

con margenes lisos; glumas y palea lisas ........... 16. Leptochloa 

Espiguillas 1.8-4.7 mm long; segunda gluma 1-nervada; plantas no estoloniferas; espiguillas comprimidas lateralmente, usualmente con 2, ocasionalmente 3 flosculos, el mas inferior perfecto, 10s flosculos superiores 

pedicelados, usualmente estaminados, reducidos y/o esteriles; lema cartacea, 

de color gris o amarillo grisaceo ............... 6. Chaboissaea 

Espiguillas 9-25 mm long; segunda gluma 2 o mas nervios; plantas 

estoloniferas; espiguillas rollizas, o comprimidas dorsalmente, con 6-20 

flosculos, 10s flosculos superiores generalmente esteriles; lema coriacea, 

lustrosa ............................... 1. Allolepis 

Flosculos esteriles 2, debajo del fertil; espiguillas con 4 flosculos, 2 esteriles, 1 

fertil, 1 reducido; pedicelos pilosos; lema del flosculo fertil con 3 aristas; 

lodiculas ausentes ..................... 3. Blepharidachne 

Flosculos esteriles arriba de 10s fertiles; espiguillas usualmente (2-)4-20 

flosculos; pedicelos glabros; lema del flosculo fertil usualmente con 1 arista; 

lodiculas presentes .............................. 34 

Lema aristada ................................. 35 

Lema mutica o mucronada .......................... 38 

Callo piloso barbado; palea cilia&, limbos con margenes engrosados; pedicelos 

lisos ..................................... 36 

Callo glabro; palea no ciliada; limbos con margenes no engrosados; pedicelos 

escabrosos .................................. 37 

Lemas ovadas a lanceoladas, apice agudo u obtuso; segunda gluma sin arista; 

raquilla glabra; inflorescencia con ramificaciones secundarias adpresas; 

pedicelos 4 mm o menos de longitud ............. 13. Erioneuron 

Espiguillas 5 o mas mm de longitud ..................... 31 

................................. 16. Leptochloa 
16 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

37(35). 

38(34). 

39(21). 

40(39). 

4 l(40). 

42(41). 

43(40). 

44(43). 

45(39). 

Lemas oblatas a forma de abanico, apice truncado; segunda gluma aristada; 

raquilla pilosa; inflorescencia con ramificaciones secundarias extendidas; 

pedicelos 5-20 mm de longitud ............... 22. Neesiochloa 

Glumas mas cortas que las espiguillas, desiguales, lisas; segunda gluma sin 

arista; raquilla glabra; nervios laterales de la lema no ciliados, a menudo 

pubescenctes, 10s pelos menos de 0.6 mm de longitud .... 16. Leptochloa 

Glumas casi igualando las espiguillas, casi iguales, escab rosas; segunda gluma 

aristada, raquilla con un fasciculo de pelos en el apice; nervios laterales de la 

lema largo ciliados, 10s pelos 1-3 mm de longitud ..... 33. Trichoneura 

Inflorescencia con ramificaciones primarias racemosas; espiguillas usualmente 

adpresas a lo largo de un raquis central triquetro; lema generalmente glabras o 

puberulentas en la parte inferior de 10s nervios ........ 16. Leptochloa 

Inflorescencia con ramificaciones primarias ramificadas; espiguillas usualmente 

extendidas a lo largo de las ramificaciones secundarias; lema generalmente 

pilosas en la parte inferior de 10s nervios ............. 34. Tridens 

Lema entera. ................................ .40 

Lema emarginada, lobada, o partida ..................... 45 

Plantas hermafroditas ............................. 41 

Plantas dioicas o monoicas .......................... 43 

Flosculos esteriles debajo de 10s fertiles; inflorescencia con las ramificaciones 

primarias racemosas; plantas introducidas para el Nuevo Mundo ....... .................................. 32. Tetrachne 

Flosculos esteriles arriba de 10s fertiles; inflorescencia con las ramificaciones 

Callo glabro; glumas casi iguales; espiguillas cleistogamas presentes en la base 

o en las axilas de 10s limbos superiores; espiguillas 6-13 flosculos; lema 

membranosa; palea con las quillas curvadas, finamente escabrido-ciliada . . ................................. 30. Steirachne 

Callo piloso; glumas desiguales; espiguillas cleistogamas ausentes; espiguillas 

................................. .25. Redfierdia 

Desarticulacion con la lema y palea cayendo separadamente; limbos con apice 

no punzante; vainas glandulas; plantas no estoloniferas; lema hialina; 

flosculos estaminados con paleas con las quillas cilioladas; flosculos pistilados 

................................ 21. Neeragrostis 

Desarticulacion con la lema y palea cayendo como una unidad; limbos con apice 

punzante; vainas no glandulas; plantas estoloniferas; lema cartacea o coriacea; 

flosculos estaminados sin paleas con las quillas cilioladas; flosculos pistilados 

Espiguillas pistiladas 0.8-3 mm de longitud; lemas de las espiguillas pistiladas 

sin arista; segunda gluma 1-nervada; espiguillas pistiladas agrupadas en las 

Espiguillas pistiladas 20-40 mm de longitud; lemas de las espiguillas pistiladas 

con 3 aristas de 3- 15 cm de longitud; segunda gluma 3-5-nervada; espiguillas 

................................ 27. Scleropogon 

Culmos cespitosos, lenosos como carrizos, 1-3 m de altura; inflorescencia una 

panicula plumosa; lemas con 10s margenes largo-vellosos cerca de la base, 10s 

pelos 3-5 mm de longitud; flosculos esteriles debajo de 10s fertiles; 

desarticulacion con la lema y palea cayendo separadamente; plantas 

primarias ramificadas; plantas nativas para el Nuevo Mundo ....... 42 

1-6 flosculos; lema cartacea; palea con las quillas no curvadas, glabra .... 

con una palea menos de la mitad de longitud de la lema; plantas anuales ... 

con una palea casi tan larga como la lema; plantas perennes ....... .44 

axilas de 10s limbos; espiguillas sesiles .............. 15. Jouvea 

pistiladas solitarias, usualmente exsertas; espiguillas pediceladas ....... 

introducidas para el Nuevo Mundo .............. 23. Neyraudia 
NUMBER 87 17 

Culmos herbaceos, cespitosos, per0 no lenosos como carrizos, 0.4-1.7 m de 

altura; inflorescencia una panicula no plumosa; lemmas ciliadas cerca de la 

base, 10s pelos usualmente menores de 3 mm de longitud; flosculos esteriles 

arriba de 10s fertiles; desarticulacion con la lema y palea cayendo como una 

46(45). Lema sin arista o mucronada, con un apice entero o emarginado; culmos 20-170 

cm de altura, erectos ........................ 34. Tridens 

Lema aristada, aristas 1.5 mm o mas de longitud, con un apice emarginado, 

lobado, o partido, cuando emarginado, entonces las plantas son decumbentes, 

con culmos de no mas de 15 cm de altura; culmos 4-100 cm de altura, 

decumbentes, o erectos ........................... 47 

47(46). Palea con 10s nervios pronunciados hasta aristas; segunda gluma aristada y mas 

larga que la lema mas inferior; palea ciliada .......... 9. Dasyochloa 

Palea con 10s nervios no pronunciados hasta aristas; segunda gluma sin arista y 

mas corta o casi igual que la lema mas inferior; palea glaba ........ 48 

48(47). Limbos con apice punzante; plantas estoloniferas, presentando fasciculos de 

hojas; espiguillas agrupadas en capitulos de 2-4, casi ocultas en 10s fasciculos 

distales de las hojas; flosculos esteriles heteromorficos ..... 20. Munroa 

Limbos con apice no punzante; plantas no estoloniferas, ni presentando 

fasciculos de hojas; espiguillas solitarias, exertas; flosculos esteriles homomorficos ................................. 49 

49(48). Plantas hermafioditas; lemas con 1 arista hasta 2.5 mm de longitud; glumas 

desiguales; espiguillas cleistogamas presentes en las vainas superiores e 

inferiores ............................. 35. Triplasis 

Plantas dioicas; lemas de las espiguillas pistiladas con 3 aristas hasta 6 mm de 

longitud; glumas casi iguales; espiguillas cleistogamas ausentes ....... .................................. .28. Sohnsia 

unidad; plantas nativas para el Nuevo Mundo ............... 46 

Synoptic Key to the New World Genera 

of the Eragrostideae 

1. Allolepis 20. Munroa 

2. Bealia 2 1. Neeragrostis 

3. Blepharidachne 22. Neesiochloa 

4. Blepharoneuron 23. Neyraudia 

5. Calamovilfa 24. Pereilema 

6. Chaboissaea 25. RedJieldia 

7. Crypsis 2 6. Reederochloa 

8. Dactyloctenium 27. Scleropogon 

9. Dasyochloa 28. Sohnsia 

10. Distichlis 29. Sporobolus 

1 1. Eleusine 30. Steirachne 

1 2, Eragrostis 3 1. Swallenia 

13. Erioneuron 32. Tetrachne 

14. Gouinia 33. Trichoneura 

15. Jouvea 34. Tridens 

16. Leptochloa 3 5. Triplasis 

17. Lycurus 36. Tripogon 

18. Monanthochloe 37. Uniola 

19. Muhlenbergia 38. Vaseyochloa 

1. Plants (8) 

*l. hermaphroditic=2-9, 11-14, 16, 17, 19, 20, 22-25, 

29-38 

2. dioecious = 1, 10, 15, 18,21,26-28 

3. monoecious = 3,27 

4. gynomonoecious = 20 

5. andromonoecious = 6 

1. annual = 2-4,6-8, 11, 12, 16, 19-22,24,29,33,35 

2. perennial = 1,3-6, 8-19,23,25-38 

1. stoloniferous = 1,8,9, 12, 13, 15, 18,20,26,27,29, 37 

2. lacking stolons=2-7, 10-14, 16, 17, 19, 21-25, 

2. Plants (6) 

3. Plants (7) 

28-36,38 

4. Plants (7) 

1. rhizomatous= 1, 3, 5, 10-12, 14, 15, 18, 19, 23, 25, 

2. lacking rhizomes = 1, 2,4, 6-9, 12-14, 16, 17, 19-22, 

28-32,34-38 

24,26,27,29,33, 34 

5. Flowering culms (6) 

1. erect = 1, 2,4-14, 16, 17, 19, 22-38 
18 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

2. decumbent=3,4,6,7,9, 12, 15, 19-21, 24 

3. mat forming = 3,7,8, 10, 12, 15, 18-21,27,29 

1. caespitose = 1,2,4-6, 8-17, 19,22,23,25-38 

2. not caespitose=3,4, 6, 7, 12, 13, 18-21,24 

1. glabrous = 1,2,4-16, 18, 19,21-27,29,30,32-38 

2. hairy = 2-4, 17, 19-21,28,31,35 

1. pubescent = 2-4, 17, 19-21,28,35 

2. pilose = 19,21, 31 

3. villous = 19,21 

9. Flowering culms (6) 

1. with viscid internodes = 12 

2. with glaucous internodes = 19 

6. Flowering culms (5) 

7. Flowering culms (6) 

8. Flowering culms (5) 

*3. with neither viscid nor glaucous internodes = 1-38 

1. cauline = 1-8, 10-12, 14-19,21-25,29-35,3738 

2. mostly basal = 3,4, 9, 12, 13, 19,20,26-28,32, 36 

1. distinctly distichous = 10, 15, 18 

10. Leaves (5) 

11. Leaves (8) 

*2. not distinctly distichous = 1-9, 11-14, 16, 17, 19-38 

12. Leaves (7) 

1. with sheath auricles = 2, 16, 19 

2. with blade auricles = 24 

3. without auricles = 1,3-23,25-38 

1. longer than internodes = 2,4, 5, 10-12, 14-16, 18, 19, 

2. shorter than internodes= 1, 3, 4, 6-9, 11-17, 19-24, 

13. Sheaths (5) 

24-26,28, 29, 3 1, 37, 38 

27-30,32-36 

14. Sheaths (8) 

1. glandular = 12,21 

*2. not glandular = 1-20,22-38 

15. Sheaths (5) 

1. with smooth margins= 1-7, 9-13, 15, 16, 18, 19, 

2. with scabrous margins = 2,4, 8, 12, 14, 17, 19-21,24, 

22-27,29-34,36-38 

28,35 

16. Sheaths (6) 

1. not ciliate= 1, 2, 4-8, 10-12, 14-16, 18, 19, 21-23, 

2. ciliate = 3, 9, 10, 12-14, 17, 19-21, 24, 26, 29, 31 

1. a membrane = 2,4, 6, 8, 14, 16, 17, 19,24,26,33 

2. a ciliate membrane= 1, 3, 10-14, 16, 18, 19, 22, 34, 

3. a line of hairs = 5, 7, 9, 12, 15, 20, 21, 23, 25, 27-32, 

4. absent=3 

25,27-30,32-38 

17. Ligule (8) 

36,38 

34, 35, 37 

18. Leaf blades (7) 

1. filifom= 4, 5, 12, 19, 25,29, 36 

2. linear = 1-1 1, 13-20,22-24,26-38 

3. triangular = 3, 12,21 

19. Leaf blades (6) 

38 

1. flat= 1-4, 6-8, 10-12, 14, 16, 17, 19-24, 27-35, 37, 

2. conduplicate = 6, 12, 13, 17-21, 27,37 

3. involute = 2-79, 10, 12, 14, 15, 19,25,26,28,29,32, 

4. terete = 29 

5. plicate = 3 

1. pungent=3,9, 10, 12, 13, 15, 18-20,26,27,31 

2. not pungent= 1, 2, 4-8, 11-14, 16, 17, 19, 21-25, 

34,35,36, 38 

20. Leaf blades (7) 

28-30,32-38 

2 1. Leaf blades (6) 

1. with thickened margins = 2,9, 13, 17, 19,20,22 

*2. without thickened margins= 1, 3-8, 10-12, 14-16, 

18,19,21,23-38 

22. Inflorescence (8) 

1. consisting of a single spikelet = 15, 18 

2. consisting of 2 or 3 spikelets = 15,26 

*3. consisting of more than 3 spikelets = 1-17, 19-25, 

27-38 

23. Inflorescence (9) 

1. a spike =no taxa 

2. a raceme = 9,22,26,27, 36 

*3. a panicle = 1-17, 19-25,27-35,3738 

24. Inflorescence (6) 

1. exserted = 1-8, 10-17, 19,21-38 

2. partially included in upper sheath = 3, 6, 7, 9, 12, 18, 

19, 21,24, 26,29, 31, 35 

3. fully included in upper sheath = 10, 15,20 

1. glandular = 2, 12,2 1,22 

25. Main axis (6) 

*2. not glandular= 1,3-17, 19,20,23-38 

26. Main axis (5) 

1. smooth= 1, 2, 4-9, 11-13, 15, 19, 21-23, 25, 26, 29, 

2. scabrous = 2,4,6, 10, 12, 14, 16, 17, 19,20,27,30,31, 

3. hairy = 3, 12, 19, 21,24, 28 

27. Primary branches (7) 

1. digitate = 8, 11 

28. Primary branches (6) 

32, 34, 37 

33-36,38 

*2. not digitate = 1-7, 9, 10, 12-17, 19-38 

1. appressed to main axis = 1, 3, 5-7, 9, 10, 12, 13, 

15-17,19-21,24,27-29,31,32,34,36,37 
NUMBER 87 19 

2. spreading from main axis = 2, 4-6, 8, 11-14, 16, 19, 

3. divaricate = 8, 12, 14, 19,25,29, 34 

4. reflexed = 8, 19,29 

1. terminating in a spikelet = 1-79-17 19-38 

2. terminating in a bare point = 8 

1. with appressed secondary branches = 1-3,5,6, 10, 12, 

2. with spreading secondary branches=2, 4, 5, 12, 19, 

3. reduced to fascicle of spikelets = 9, 12, 24 

1. glandular = 2,4,21,22 

22-24,26,28-30,33-35,37,38 

29. Primary branches (8) 

30. Primary branches (7) 

13, 15, 16, 19,21,23,27-31,35, 37,38 

22, 25,29,34, 37,38 

31. Pedicels (6) 

*2. not glandular= 1, 3, 5-7, 9, 10, 12-14, 16, 17, 19-21, 

23-38 

32. Pedicels (6) 

1. glabrous= 1, 2, 4-6, 9, 10, 12-14, 16, 17, 19-27, 29, 

2. hairy = 3, 19, 21, 24,28, 31 

1. pubescent = 3, 19,21, 28 

2. pilose = 19, 21, 24, 31 

3. villous = 19,21,24 

1. smooth= 1, 3-5, 9, 12, 13, 19, 21, 22, 24-26, 29, 32, 

2. scabrous=2, 6, 10, 12, 14, 16, 17, 19, 20, 23, 24, 27, 

30,32-35,37,38 

33. Pedicels (5) 

34. Pedicels (5) 

34,37 

28,30,31,33-35,38 

35. Cleistogamous spikelets (7) 

1. present = 12, 16, 19,29, 30, 35 

*2. absent = 1-29,31-34,36-38 

1. below glumes = 7, 19,29, 37 

2. above glumes = 1-36,38 

1. lemma and palea falling as a unit = 1-20, 22, 24-36, 

2. lemma and palea falling separately = 7, 12, 21, 23 

1. hairy = 2, 3, 5, 6, 13, 14, 19,22,24,25,27,28,31,35, 

2. glabrous = 1, 4, 6-12, 15-21, 23, 26, 27, 29, 30, 

36. Disarticulation (9) 

37. Disarticulation (8) 

38 

38. Callus (7) 

38 

32-34,36,37 

39. Spikelets (8) 

1. up to 4.9 mm long=2, 4, 6-8, 12, 16, 17, 19, 24, 29, 

2. greater than 4.9 mm long = 1, 3, 5, 8-16, 18-23, 

32, 34, 36 

25-28,30-38 

40. Spikelets (7) 

1. in clusters = 12, 15,20,2 1,24 

2. paired = 17 

3. solitary= 1-14, 16, 18, 19,22,23,25-38 

1. subtended by sterile, bristle-like spikelets = 24 

41. Spikelets (8) 

*2. not subtended by sterile, bristle-like spikelets = 1-23, 

25-38 

42. Spikelets (7) 

1. laterally compressed = 2, 3, 5-16, 18-23, 25-28, 

2. terete= 1,2,4, 12, 16, 17, 19, 24,27,29,33 

3. dorsiventrally compressed = 19 

30-32,34-38 

43. Spikelets (7) 

1. sessile=7, 8, 11, 12, 15, 18, 21,24 

2. subsessile = 3, 6, 7, 12, 14, 16, 19-21, 24, 29, 32, 33, 

3. pedicellatez 1-6, 9, 10, 12-14, 16, 17, 19-31, 

36 

33-35,3738 

44. Glumes (8) 

*l. present = 1-17, 19-38 

2. absent = 15, 18,20 

45. Glumes (8) 

1. shorter than spikelets= 1, 4, 6-8, 10-17, 19-26, 

2. equalling spikelets = 2-7, 13, 19,2728, 31,33, 34 

3. exceeding spikelets = 2, 19 

28-30,32,34-38 

46. Glumes (7) 

1. unequal=4, 5, 8, 11-16, 19-21, 23-26, 29, 34-36, 

2. more or less equal = 1-4,6, 7, 9, 10, 12, 13, 17, 19,20, 

38 

22,24,27,28,30,3 1-34,37 

47. Glumes (5) 

1. smooth= 1-5, 8-10, 12, 13, 15, 16, 19-32,34, 37, 38 

2. scabrous=2,6, 7, 11, 12, 14, 17, 19, 33,35, 36 

48. Glumes (7) 

1. glabrous = 1, 3-16, 19-38 

2. hairy = 2, 17, 19, 21 

49. First glume (8) 

1. up to 1-nerved= 1-9,ll-16,19-25,27-30,32-36 

2. greater than 1-nerved= 10, 14, 17, 19, 26, 27, 31, 37, 

38 

50. Second glume (7) 

1. shorter than lower lemma= 1, 4, 6, 8, 10-17, 19-21, 

2. subequal to lower lemma = 2-5, 7, 19, 22, 27-29, 3 1, 

3. longer than lower lemma = 2, 9, 13, 19 

23-26,28, 30, 32, 34, 37, 38 

33-36 

51. Second glume (7) 

1. awned = 6, 8,9, 17, 19,22,24,27, 33 
20 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

2. unawned = 1-7, 10-16, 19-21,23,25-32,34-38 

1. up to 1-nerved=2-9, 12, 13, 15-17, 19-25, 28-30, 

2. greater than 1-nerved = 1, 10, 11, 14, 16, 17, 19,21,26, 

52. Second glume (8) 

32-36 

2x3 1,34,37,38 

53. Rachilla (8) 

1. pronounced between florets = 1,3,6,8-16,18,20-23, 

*2. not pronounced between florets = 1,2,4-6, 17, 19,24, 

25-28,30-38 

29 

54. Rachilla (7) 

1. hairy = 3, 22,23, 28, 30, 31,38 

2. glabrous = 1,6, 8-16, 18,20,21,25-2732-37 

1. up to 1 per spikelet = 2,4-7, 17, 19,24,29 

2. 2-4 per spikelet=3, 6, 8, 12, 14, 16, 18, 20, 23, 

3. more than 4 per spikelet = 1, 8-16, 18, 20-23, 25-28, 

55. Florets (9) 

25-28,3 1, 34, 35 

30-34,36-38 

56. Sterile florets (7) 

1. present = 1, 3, 6, 8-18,20-28,30-38 

*2. absent = 2,4-7, 12, 19,29 

57. Sterile florets (8) 

1. above fertile florets= 1, 6, 8-16, 18, 20-22, 25-28, 

2. below fertile florets = 3,23, 32, 37 

30,31,33-38 

58. Sterile florets (7) 

*l. homomorphic = 1,3,6,8-18,21-23,25-28,30-38 

2. heteromorphic = 20,24 

1. entire= 1, 4-8, 10-12, 14-19, 21, 24-27, 29-32, 37, 

2. emarginate= 13, 16, 19,20,22, 33, 34, 36 

3. lobed = 2, 9, 13, 16, 20,35 

4. cleft = 3, 9, 23, 28 

1. awned = 2, 3, 6, 8, 9, 13, 14, 16, 17, 19-24, 2728, 33, 

2. mucronate=6, 8, 12, 16, 19,21,25, 30,34 

3. unawned= 1, 4-7, 10-12, 15, 16, 18, 19, 26, 27, 29, 

59. Lemma(8) 

38 

60. Lemma(8) 

35,36 

31, 32, 37, 38 

61. Lemma (7) 

1. glabrous= 1, 5, 7, 8, 10-12, 15, 16, 18, 19, 21, 22, 

2. hairy= 2-6, 9, 13, 14, 16, 17, 19-21, 23-25, 28, 29, 

26-30,32,33,36,37 

3 1, 34, 35, 38 

62. Lemma (6) 

1. pubescent=6, 16, 17, 19, 21,24,25,29, 34, 38 

2. pilose = 13, 14, 19,21,24,28,29, 38 

3. villous=2-4,9, 14, 19,21,23, 31,35 

1. smooth= 1, 3-5, 8-10, 12, 13, 15, 16, 18, 19, 21-23, 

2. scabrous = 2,6,7, 11, 12, 14, 17, 19,20,24,30,33,36 

1. up to 1-nerved = 5, 729 

2. with more than 1 nerve = 1-4,6,8-28,30-38 

63. Lemma(5) 

25-29,3 1, 32,34, 35,37,38 

64. Lemma (9) 

65. Lemma(7) 

1. 

2. 

3. 

4. 

5. 

6. 

hyaline= 7, 12, 19, 21, 34 

membranous=2-4, 7-9, 11-14, 16, 17, 19, 20, 

chartaceous = 5,6, 12, 15, 17, 19,25,31,38 

coriaceouS= 1, 10, 12, 18,20,26,27,37 

cartilaginous = no taxa 

indurate = 12, 18 

22-24,28-30,32-36 

66. Lemma(6) 

1. with glabrous nerves= 1, 5, 7, 8, 10-12, 14-19, 21, 

2. with hairy nerves = 2-6, 9, 13, 16, 19, 20, 22-24, 28, 

25-30,32,36-38 

31,33-35 

67. Palea (7) 

1. glabrous= 1, 6-8, 10-12, 14-16, 18-21, 23, 25-30, 

2. hairy=2-5,9, 12, 13, 17, 19,21, 22,24, 31,34, 35 

1. extending into awns = 6, 14, 19 

2. not extending into awns = 1-13, 15-38 

1. hyaline = 7, 12, 19, 21, 34 

2. membranous=2-4, 8-14, 16, 17, 19, 20, 22-24, 

3. chartaceous = 5,6, 10, 12, 15, 19,25-2231,3738 

4. coriaceous = 1, 18 

5. cartilaginous = no taxa 

6. indurate = 18 

32-34,37,38 

68. Palea (8) 

69. Palea (6) 

27-30,32-36 

70. Palea (5) 

* 1. margins enfolding fruit = 1,2,4, 6, 10, 12, 17-19,24, 

2. margins not enfolding fruit = 3, 5, 7-9, 11, 13-16, 

26 

20-23,25,27-38 

71. Palea (7) 

1. ciliate= 1, 3, 5, 9, 12-14,21, 22, 31, 37 

*2. not ciliate=2, 4, 6-8, 10-12, 14-20, 23-30, 32-36, 

38 

72. Palea (6) 

1. smooth= 1-5, 7-10, 12, 13, 15, 16, 18-23, 25-29, 

31-38 
NUMBER 87 21 

2. scabrous = 6, 11, 12, 14, 17, 19,24,30 

73. Lodicules (6) 

*l. present = 1, 2,4-6, 8-17, 19-38 

2. absent = 3, 7, 18,20, 27,29 

1. adnate to palea = 13, 34 

74. Lodicules (6) 

*2. not adnate to palea = 1, 2,4-6, 8-12, 14-17, 19-38 

75. Lodicules (5) 

1. truncate = 2, 4-6, 8, 10, 12, 14-17, 19-21, 24, 27-32, 

2. rounded = 25,33,34 

3. cuneate= 1, 13 

4. acuminate = 1 1,22, 23 

1. up to 2 = 3, 7, 12, 13, 16,20,24,29,30, 36 

2. greater than 2 = 1-29, 31-38 

1. yellow = 1, 3, 5, 8-13, 15-21, 23-25, 27, 29, 32, 36, 

2. reddish purple=2, 4, 6, 7, 12, 14-17, 19, 25, 28-35, 

3. olivaceous plumbeous = 6, 19,22,26, 29 

35-38 

76. Stamens (6) 

77. Anther (6) 

37 

38 

78. Stigmas (5) 

1. UP to 2 = 1-25,27-38 

2. greater than 2 = 20 

1. with free pericarp = 5, 7, 8, 11,29,32, 37 

79. Fruit (8) 

*2. with adnate pericarp= 1-4, 6, 9, 10, 12-28, 30, 31, 

33-36,38 

80. Caryopsis (6) 

1. dorsiventrally compressed= 16,20,22, 33-35 

2. terete = 2, 4-15, 17-19, 21, 23, 25, 27, 29-32, 36-38 

3. laterally compressed = 3, 12, 16, 19,24,26 

1. with persistent style bases = 3 1, 38 

81. Caryopsis (9) 

*2. lacking persistent style bases = 1-30,32-37 

82. Caryopsis (8) 

1. with pronounced, sharp-pointed style bases = 38 

2. with relatively short and blunt style bases = 3 1 

1. 7=3,20 

2. 8 = 2,4, 6, 7, 9, 13, 20 

3. 9 or more= 1, 5, 7, 8, 10-12, 14-17, 19, 21, 24-27, 

83. Base chromosome number, x = (5) 

29,31,33-37 

84. Distribution by continent (5) 

1. North America= 1-13, 16-21,23-29,31-38 

2. Central America=7, 8, 10-12, 14-21, 23, 24, 29, 

34-37 

3. South America = 3,6,8, 10-14, 16-20,22,24,27,29, 

4. Africa = 58, 11, 12, 16,29,32-34,36 

5. Europe = 78, 11, 12, 16,29 

6. Asia = 7, 8, 11, 12, 16, 19, 29, 33, 36 

7. Australia = 8, 10-12, 16,29 

8. Pacific Islands = 11, 12, 16, 19,29, 33 

1. Greenland = no taxa 

2. Alaska= 10,19 

3. Canada= 10, 12, 19,20,29,35 

4. United States= 1, 3-5, 7-13, 16-21, 23, 25, 27, 29, 

5. Mexico = 1-4,6-21,23,24,26-29,33-37 

6. Central America = 8, 11, 12, 14-17, 19,24,29,35,37 

7. West Indies = 8, 11, 12, 14, 16, 18, 19, 29, 36, 37 

30,32-34,36,37 

85. Distribution for North America and Mesoamerica (5) 

31-38 

86. Regions of the United States divided by states (5) 

1. Northern Pacific Region = 7,8,10- 12, 16, 19,29 

2. California Region = 7, 8, 10-12, 16, 18-20, 27, 29, 31 

3. Southwestern Region = 4, 5, 8-13, 16, 17, 19, 20, 25, 

4. Northern Plains Region = 8-13, 16, 19-21, 25, 29, 35 

5. Central Plains Region = 3, 5, 8-13, 16, 19-21,25, 29, 

6. Texan Region= 1, 3-5, 8-13, 16, 18-21, 25, 27, 29, 

7. Southeastern Region= 8, 10-12, 16-19, 21, 23, 29, 

8. Midsouth Region = 8, 11, 12, 16, 19,21,29,37 

9. Great Lakes Region = 7, 8, 11, 12, 16, 19,21,29 

10. North Atlantic Region = 8, 10-12, 16, 19,29 

11. Central Atlantic Region = 8, 10-12, 16, 19, 29, 32, 37 

12. Alaskan Region = 11,12, 19 

87. Distribution for South America (5) 

27,29,34,35 

34,35 

33-38 

34,35,37 

1. Colombia = 11, 12, 17, 19,24, 29, 37 

2. Venezuela = 11, 12, 16, 19, 24, 29, 30 

3. Guiana, Surinam, or French Guiana= 11, 12, 24, 29, 

4. Ecuador = 10-12, 17, 19,24,29,33,37 

5. Peru = 11-13,19,24,29,33 

6. Brazil = 11, 12, 14, 16, 19,22,24,29, 30 

7. Bolivia = 6, 10-14, 16, 17, 19,20, 29, 34 

8. Paraguay = 11, 12, 14, 16,29 

9. Uruguay = 8, 11, 12, 16, 29 

10. Chile = 8, 10-12, 19,20,27, 29, 36 

11. Argentina = 3, 6, 8, 10-14, 16-20,27,29, 32,34,36 

30 

88. Whether native or introduced (6) 

1. Native to New World = 1-6,9-22,24-3 1,33-38 

2. Introduced to New World = 7, 8, 11, 12, 16,23,29,32 
22 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Taxonomy 

ERACROSTIDEAE Stapf, F1. Cap. 7:316. 1898. 

Plants hermaphroditic (30), dioecious (8), monoecious (2), 

gynomonoecious (l), or andromonoecious (1); annual (17) or 

perennial (32); stoloniferous (12) or lacking stolons (29); 

rhizomatous (22) or lacking rhizomes (22). Flowering culms 

erect (33), decumbent (1 l), or mat forming (12); caespitose 

(32) or not caespitose (11); glabrous (33) or hairy (10); 

pubescent (9/10), pilose (3/10), or villous (2/10); with viscid 

internodes (l), glaucous internodes (l), or with neither viscid 

nor glaucous internodes (38). Leaves cauline (31) or mostly 

basal (12); distinctly distichous (2) or not distinctly distichous 

(36); with sheath auricles (3), with blade auricles (l), or without 

auricles (36). Sheaths longer (19) or shorter than internodes 

(29); glandular (2) or not glandular (37); with smooth (31) or 

with scabrous margins (12); not ciliate (30) or ciliate (14). 

Ligule a membrane (1 l), a ciliate membrane (14), a line of hairs 

(18), or absent (1). Leaf blades filiform (7), linear (35), or 

triangular (3); flat (30), conduplicate (lo), involute (21), terete 

(l), or plicate (1); pungent (12) or not pungent (29); with (7) or 

without thickened margins (32). Inflorescence consisting of a 

single spikelet (2), two or three spikelets (2), or more than three 

spikelets (36); a raceme (5/37) or a panicle (35/37); exserted 

(35), partially included in upper sheath (13), or fully included 

(3). Main axis glandular (4/37) or not glandular (34/37); 

smooth (22/37), scabrous (18/37), or hairy (6/37). Primary 

branches digitate (2/37) or not digitate (35137); appressed to 

main axis (24/37), spreading from main axis (23/37), divaricate 

(7/37), or reflexed (3/37); terminating in a spikelet (36/37) or 

terminating in a bare point (1137); with appressed secondary 

branches (21/27), with spreading secondary branches (1 1/27), 

or reduced to fascicle of spikelets (3127). Pedicels glandular 

(4/34) or not glandular (31/34); glabrous (29/32) or hairy 

(6/32); pubescent (4/6), pilose (4/6), or villous (3/6); smooth 

(1 7/32) or scabrous (1 9/32). Cleistogamous spikelets present 

(6) or absent (36). Disarticulation below glumes (4) or above 

glumes (37); lemma and palea falling as a unit (35/37) or 

lemma and palea falling separately (4/37). Callus hairy (1 5) or 

glabrous (26). 

Spikelets in clusters (5), paired (l), or solitary (33); 

subtended by sterile, bristle-like spikelets (1) or not subtended 

by sterile, bristle-like spikelets (37); laterally compressed (32), 

terete (1 l), or dorsiventrally compressed (1); sessile (8), 

subsessile (14), or pedicellate (3 1); 0.5-40 (average 9.06) mm 

long. Glumes present (37) or absent (3); shorter than spikelets 

(30/36), about equalling spikelets (1 3/36), or much exceeding 

spikelets (2/36); unequal (21/37) or more or less equal (23/37); 

smooth (29/37) or scabrous (1 1/37); glabrous (35/37) or hairy 

(4/37). First glume 0-%nerved (usually 2). Second glume 

shorter than lower lemma (25/37), about same length as lower 

lemma (15/37), or longer than lower lemma (4137); awned 

(9/37) or unawned (31/37); 1-1 1-nerved (usually 2). Rachilla 

pronounced between florets (30/37) or not pronounced between 

florets (9137); hairy (7/30) or glabrous (23/30). Florets 1-60 

(usually 7) per spikelet. Sterile florets present (32) or absent 

(8); above fertile florets (27130) or below fertile florets (4/30); 

homomorphic (30/32) or heteromorphic (2132). Lemma entire 

(26), emarginate (8), lobed (6), or cleft (4); awned (20), 

mucronate (9), or unawned (19); glabrous (22) or hairy (22); 

pubescent (10/20), pilose (8/20), or villous (1 0/20); smooth 

(27) or scabrous (13); 1-4-13-nerved; hyaline (5), membranous (25), chartaceous (9), coriaceous (8), or indurate (2); with 

glabrous nerves (24) or with hairy nerves (18). Palea glabrous 

(26137) or hairy (15137); extending into awns (3) or not 

extending into awns (37); hyaline (5), membranous (26), 

chartaceous (12), coriaceous (2), or indurate (1); margins 

enfolding fruit (1 1) or margins not enfolding hit (27); ciliate 

(1 1) or not ciliate (29); smooth (32) or scabrous (8). Lodicules 

present (35) or absent (6); adnate to palea (2/35) or not adnate 

to palea (34135); truncate (25/33), rounded (3/33), cuneate 

(2/33), or acuminate (3133). Stamens 1 (2), 2 (9), or 3 (37). 

Anther yellow (24), reddish purple (20), or olivaceous 

plumbeous (5). Stigmas 2 (37/37) or 3 (1/37). Fruit with free 

pericarp (7) or with adnate pericarp (31). Caryopsis dorsiventrally compressed (6/36), terete (27/36), or laterally compressed 

(6136); with persistent style bases (2) or lacking persistent style 

bases (36). Caryopsis with pronounced, sharp-pointed style 

bases (1/2) or with relatively short and blunt style bases (1/2). 

Base chromosome number of x = 7 (2/32), x = 8 (7/32), x = 9 

(4/32), x = 10 (18/32), x = 12 (1/32), x = 20 (3/32), or x = 30 

(1/32). 

DISTRIBUTION.-North America (34) (Alaska (2/36), Canada (6/36), United States (29/36), Mexico (31/36), or West 

Indies (7/36)), Central America (20), South America (23) 

(Colombia (7/23), Venezuela (7/23), Guiana, Surinam, French 

Guiana (5/23), Ecuador (9/23), Peru (7/23), Brazil (9/23), 

Bolivia (12/23), Paraguay (5/23), Uruguay (5/23), Chile (9/23), 

or Argentina (18/23)), Africa (lo), Europe (6), Asia (9), 

Australia (6), or Pacific Islands (6). Regions of United States 

divided by states: Northern Pacific Region (8/29), Californian 

Region (12/29), Southwestern Region (17/29), Northern Plains 

Region (13/29), Central Plains Region (16/29), Texan Region 

(24/29), Southeastern Region (14/29), Midsouth Region (8/29), 

Great Lakes Region (8/29), North Atlantic Region (7/29), 

Central Atlantic Region (9/29), or Alaskan Region (3/29). 

Genus native to the New World (34) or genus introduced to the 

New World (8). 

1. Allolepis Soderstr. & H.F. Decker, Madrono 18:36. 1965.- 

Type: Allolepis texunu (Vasey) Soderstr. & H.F. Decker. 

Plants dioecious; perennial; stoloniferous (5-25 cm long, 

1-4 mm wide, glabrous); rhizomatous or lacking rhizomes. 

Flowering culms erect (10-70 cm long, nodes 3 or more); 

caespitose; glabrous. Leaves cauline; without auricles. Sheaths 

shorter than internodes; with smooth margins; not ciliate. 

Lirmle a ciliate membrane (0.5-1.4 mm long). Leaf blades 
NUMBER 87 23 

linear; flat (5-30 cm long, 2.5-6 mm wide, sometimes 

involute toward tip); not pungent; without thickened margins 

(edges scabrous). Inflorescence a panicle (3-23 cm long, 1-6 

cm wide); narrow; exserted. Main axis smooth. Primary 

branches appressed to main axis (usually floriferous to base); 

terminating in a spikelet; with appressed secondary branches. 

Pedicels glabrous; smooth. Disarticulation above glumes; 

lemma and palea falling as a unit. Callus glabrous. Spikelets 

9-25 mm long; solitary (ovate to lanceolate-linear, stamineous, 

lustrous); terete (female spikelets slightly compressed); pedicellate. Glumes shorter than spikelets; more or less equal; 

smooth; glabrous. First glume 1 -nerved (up to 4 to 5 additional 

faint nerves present in female spikelet). Second glume shorter 

than lower lemma; unawned; 3-nerved (additional 1 or 2 pairs 

of faint nerves sometimes present in female spikelet). Rachilla 

pronounced or not pronounced between florets; glabrous. 

-- Florets 6-20 per spikelet. Sterile florets present; above fertile 

florets. Lemma entire; unawned; glabrous; smooth; strongly 

3-nerved; coriaceous; with glabrous nerves. Palea glabrous; not 

extending into awns; coriaceous; ciliate; smooth. Lodicules 

cuneate. Stamens 3. Anthers yellow. Stigmas 2. Base chromosome number of x = 20. 

DISTRIBUTION.-North America. United States (Texan Region) and Mexico. Native to the New World. 

REMARKS.-The only species in the genus was first 

described by Vasey (1 890) as belonging to the genus Poa. He 

later changed his mind and redescribed it in Seiglingia 

Bernhardi, a genus now placed in Danthonia DC. (Clayton and 

Renvoize, 1986). Due to its dioecious habit, characteristic 

inflorescence, subcoriaceous glumes, exserted styles, and 

grains enclosed by a coriaceous palea base, Scribner (1899) 

transferred this species to Distichlis. 

Allolepis is very similar to Distichlis, sharing the dioecious 

habit, a ciliate membrane for a ligule, disarticulation above the 

glumes, and many florets per spikelet. The genus seems closely 

allied with other members of the subtribe Monanthochloinae, 

which includes Distichlis, Jouvea, Monanthochloe, Reederochloa, and Swallenia (Clayton and Renvoize, 1986; Peterson et 

al., 1995). Soderstrom and Decker (1965) found normal, 

eragrostoid-like, bicellular microhairs in Allolepis and bicellular microhairs with enlarged bases that are sunken in the leaf 

epidermis in all species of Distichlis, Monanthochloe, and 

Reederochloa. In addition to these differences, Allolepis differs 

from Distichlis by possessing 3-nerved lemmas, long stolons, 

and a nondistichous leaf arrangement. 

2. Bealia Scribn., True Grasses 104, fig. 45a. 1890. Trans. 

from Engl. and Prantl, Nat. Pflanzenfam., by Scribner and 

Southworth.-Tpe: Bealia mexicana Scribn. 

Plants annual; lacking stolons; lacking rhizomes. Flowering 

culms erect (much branched at lower nodes, 9-35 cm tall); 

caespitose; glabrous or hairy; pubescent. Leaves cauline; with 

sheath auricles. Sheaths longer than internodes; with smooth or 

scabrous margins; not ciliate. Ligule a membrane (margins 

decurrent, usually splitting to form auricles). Leaf blades linear 

(1-7 cm long, 0.6-1.4 mm wide); flat or involute; not pungent; 

with thickened whitish margins. Inflorescence a panicle (3-10 

cm long, 1.5-3.2 cm wide); exserted (sinuously ascending or 

flexuous). Main axis minutely glandular; smooth or scabrous. 

Primary branches spreading from main axis; terminating in a 

spikelet; with appressed or spreading secondary branches. 

Pedicels minutely glandular; glabrous; scabrous. Disarticulation above glumes; lemma and palea falling as a unit. Callus 

hairy. Spikelets 3.2-4.8 mm long; solitary (grayish green); 

laterally compressed or terete; pedicellate (pedicels 1-5.5 mm 

long). Glumes about equalling or much exceeding spikelets; 

more or less equal; smooth or scabrous; hairy. First glume 

1-nerved. Second glume about same length or longer than 

lower lemma; unawned; 1-nerved. Florets 1 Er spikelet. 

Lemma lobed (lobes 1-1.4 mm long); awned (awn crispedcurled to flexuous, 4-6.5 mm long); hairy; villous; scabrous; 

3-nerved; membranous; with hairy nerves. Palea hairy (appressed villous on lower 2/3); not extending into awns; 

membranous; smooth. Lodicules truncate. Stamens 3. Anther 

reddish purple. Stigmas 2. Caryopsis terete (fusiform, olive 

brown). Base chromosome number of x = 8. 

DISTRIBUTION.-NO~~~ America. Mexico. Native to the New 

World. 

REmS.-Vasey (1899) and Scribner (in Hackel, 1890) 

were the first to recognize the distinctive morphological 

features that distinguish Bealia mexicana from other members 

ofMuhlenbergia. It has deeply bilobed lemmas with rounded to 

obtuse lobes, pilose or villous glumes that are 1-nerved and 

subequal to or longer than the lemma, a crisped-curled to 

flexuous awn borne between the lobes, and minutely glandular 

pedicels. Besides the morphological differences, Bealia has a 

base chromosome number of x = 8 and has relatively large 

chromosomes compared to those of Muhlenbergia (Peterson, 

1988,1989). Although Blepharoneuron, Dasyochloa, Erioneuron, and Munroa share a base chromosome number of x = 8, 

only Blepharoneuron appears to be closely related to Bealia. 

Based on restriction fragment analysis of chloroplast DNA 

(cpDNA), Bealia and Blepharoneuron always form a clade 

within the monophyletic subtribe Muhlenbergiinae (Duvall et 

al., 1994). A recent study also indicated that Bealia is 

allozymically very similar to Muhlenbergia argentea Vasey 

(Peterson et al., 1993). 

3. Blephariduchne Hack., in Engl. and Prantl, Nat. Pflanzenfam. 2(2):68. 1887.-Lectotype: Blepharidachne kingii 

(S. Watson) Hack. (see Hitchc., U.S.D.A. Bull. 772:78. 

1920). 

Plants hermaphroditic or monoecious; annual (rarely) or 

perennial; lacking stolons; rhizomatous. Flowering culms 

decumbent or mat forming (3-8(-20) cm tall); not caespitose 

(from a knotty base); hairy; pubescent. Leaves cauline or basal; 
24 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

not distinctly distichous; without auricles. Sheaths shorter than 

internodes; with smooth margins; ciliate. L&& _a Filiate 

membrane or absent. Leaf blades linear or triangular (8-20 mm 

long, clustered, sometimes with dense covering of white 

indumentum); flat, involute, or plicate; pungent. Inflorescence 

a panicle (1-3 cm long, narrow, oblong); exserted or partially 

included in upper sheath. Main axis hairy. Primary branches 

appressed to main axis; terminating in a spikelet; with 

appressed secondary branches. Pedicels hairy; pubescent; 

smooth. Disarticulation above glumes (but not between 

florets); lemma and palea falling as a unit. Callus hairy. 

Spikelets 5-7 mm long; solitary; laterally compressed; 

subsessile or pedicellate. Glumes about equalling spikelets; 

more or less equal; smooth; glabrous. First glume l-nerved. 

Second glume about same length as lower lemma; unawned; 

1 -nerved. Rachilla pronounced between florets; hairy. Florets 4 

per spikelet (but only third floret fertile). Sterile florets present 

(2, staminate or sterile, below fertile floret and usually 1, 

reduced to 3-aristate rudiment, above fertile floret). Lemma 

cleft (3-cleft, 2 basal lemmas with deeper incisions); awned (2 

lateral lobes mucronate, third lemma 3-aristate); hairy; villous; 

smooth; 3-nerved; membranous; with hairy nerves. Palea hairy; 

not extending into awns; membranous; margins not enfolding 

fruit; ciliate; smooth. Lodicules absent. Stamens 2 or 3 (rarely 

1). Anther yellow. Stigmas 2. Caryopsis laterally compressed. 

Base chromosome number of x = 7. 

DISTRIBUTION.-North America and South America. United 

States (Central Plains Region and Texan Region) and Mexico. 

South America (Argentina). Native to the New World. 

REmms.-Watson (1871) initially published two North 

American species in Eremochloe, which is an illegitimate name 

because of the previously published genus Eremochloa Biise. 

Hackel (1887) later proposed the new name to replace the 

illegitimate one. Hitchcock (1920) recognized the disjunct 

nature of the genus and transferred the South American 

Munroa benthamiana Hack. to Blepharidachne. Four species 

are recognized in this North/South American disjunct genus, 

two in Argentina and two in western North America. The South 

American species have flat leaf blades, three stamens, and an 

annual habit, whereas the North American species have folded 

or involute leaf blades, two stamens, and a perennial habit 

(Sanchez, 1983b). Based on similar anatomical characteristics, 

Sanchez (1983a) placed the genus near Dasyochloa. Hunziker 

and Anton (1979) recognized the morphological similarities of 

this genus to Munroa. The cleft, lobed to emarginate lemma 

apex also unites these three genera with Erioneuron. Munroa 

appears to be the closest sister to Blepharidachne because they 

share a base chromosome number of x = 7. 

4. Blepharoneuron Nash, Bull. Torrey Bot. Club 25:88. 

1898.-Tpe: Blepharoneuron tricholepis (Tom.) Nash. 

Plants annual or perennial; lacking stolons; lacking rhizomes. Flowering culms erect or decumbent (10-70 cm tall); 

caespitose or not; glabrous or hairy; pubescent. Leaves cauline 

or mostly basal; without auricles. Sheaths longer or shorter than 

internodes; with smooth or scabrous margins; not ciliate. 

Ligule a membrane (translucent to whitish, margins decurrent). 

Leaf blades filiform to linear; flat or involute; not pungent. 

Inflorescence a panicle (3-25 cm long, 1-10 cm wide); 

exserted. Main axis smooth or scabrous. Primary branches 

spreading from main axis; terminating in a spikelet; with 

spreading secondary branches. Pedicels glandular (minutely 

granular just below spikelet); glabrous (capillary, wiry, and 

flexuous, usually nodding to reflexed); smooth. Disarticulation 

above glumes; lemma and palea falling as a unit. Callus 

glabrous. Spikelets 2-3.9 mm long; solitary (grayish green); 

terete; pedicellate (pedicels 2-12 mm long). Glumes shorter or 

about equalling spikelets; unequal or more or less equal; 

smooth; glabrous. First glume l-nerved. Second glume shorter 

or about same length as lower lemma; unawned; l-nerved. 

Florets 1 spikelet. Lemma entire; unawned (occasionally 

mucronate); hairy; villous; smooth; 3-nerved; membranous; 

with hairy nerves (silky hairs up to 1 mm long). Palea hairy; not 

extending into awns; membranous; smooth. Lodicules truncate. 

Stamens 3. Anther reddish purple. Stigmas 2. Caryopsis terete 

(fusiform to ellipsoid, brownish). Base chromosome number of 

x=8. 

DISTRIBUTION.-North America. United States (Southwestern Region and Texan Region) and Mexico. Native to the New 

World. 

REMARKS.-Blepharoneuron historically contained a single, 

perennial species, B. tricholepis, ranging from Colorado to 

Central Mexico. This species was originally placed in Viva 

Beauv. by Torrey (1856) and was transferred to Sporobolus by 

Coulter (1885). Nash (1898) disagreed with Coulter’s treatment 

and proposed the generic name Blepharoneuron, which 

emphasizes the hairy and prominently nerved lemma and palea. 

The only other species included in the genus, B. shepherdii 

(Vasey) P.M. Peterson & Annable, was first placed in 

Sporobolus by Vasey (1887a) and later was transferred to 

Muhlenbergia by Swallen (1 947). Peterson (1 988) found B. 

shepherdii to possess a base chromosome number of x = 8 and 

presented a revision (Peterson and Annable, 1990). The two 

species of Blepharoneuron differ from other eragrostoid genera 

by having a single floret per spikelet, densely appressed to 

spreading silky whitish hairs on the midnerve and margins of 

the lemma, minutely glandular and capillary, wiry, flexuous, 

usually nodding, and reflexed pedicels, and hairy paleas. 

Reeder (1971) suggested that Blepharoneuron may form an 

alliance with Erioneuron because it shares certain morphological features with that genus, and because it shares a base 

chromosome number of x = 8. On the basis of cork and silica 

cell distribution on the surface of the lemma, Valdes-Reyna and 

Hatch (1991) suggested that Blepharoneuron is allied with 

Chaboissaea, Crypsis, Lycurus, Muhlenbergia, and Sporobolus. Cladistic analysis of cpDNA restriction fragment variation 

suggests that Blepharoneuron and Bealia share a most recent 
NUMBER 87 25 

common ancestor within the monophyletic subtribe Muhlenbergiinae (Duvall et al., 1994). 

5. Culumoviljiu (A. Gray) Hack., True Grasses 113. 1890. 

Trans. from Engl. and Prantl, Nat. Pflanzenfam., by 

Scribner and Southworth.-Lectotype: Calamovilfa brevipilis (Torr.) Scribn. in Hack. (see Hitchcock, U.S.D.A. 

Bull. 772:126. 1920). 

Plants perennial; lacking stolons; rhizomatous (wiry). Flowering culms erect (50-200 cm tall, thick, semisolid); caespitose; glabrous. Leaves cauline; without auricles. Sheaths longer 

than internodes; with smooth margins; not ciliate (sometimes 

ciliate near collar). Ligule a line of hairs. Leaf blades filiform to 

linear (10-80 cm long, 2-8 mm wide, tapering to a long, fine 

point); involute (flat near base); not pungent. Inflorescence a 

panicle (10-25(-60) cm long); exserted. Main axis smooth. 

Primary branches appressed or spreading from main axis; 

terminating in a spikelet; with appressed or spreading secondary branches. Pedicels glabrous; smooth. Disarticulation 

above glumes; lemma and palea falling as a unit. Callus hairy 

(blunt, with soft white hairs). Spikelets 5-10 mm kmg; 

solitary; laterally compressed; pedicellate. Glumes about 

equalling spikelets; unequal (first glume shorter than second 

glume); smooth; glabrous. First glume 1 -nerved. Second glume 

about same length as lower lemma; unawned; 1 -nerved. Florets 

1 per spikelet. Lemma entire (3-5 mm long); unawned; 

glabrous or hairy; smooth; 1-nerved; chartaceous; with 

glabrous or hairy nerves. Palea hairy; not extending into awns; 

chartaceous; margins not enfolding fruit; ciliate; smooth. 

Lodicules truncate. Stamens 3. Anther yellow. Stigmas 2. Fruit 

with free pericarp. Achene terete. Base chromosome number of 

x= 10. 

DISTRIBUTION.-North America. United States (Southwestern Region, Central Plains Region, and Texan Region). Native 

to the New World. 

REMARKS.-Asa Gray first recognized the distinctive features of the taxon (Thieret, 1966) by erecting section 

Calamovilfa within Calamagrostis Adans. Hackel (1890) later 

raised the section to genus level and suggested it was closely 

related to Ammophila Host. Using information from anatomy, 

cytology, embryology, and gross morphology, Reeder and 

Ellington (1960) proposed that Calamovilfa was more closely 

aligned with Sporobolus and other chloridoid eragrostoids. The 

genus is characterized by having single-flowered spikelets, 

1-nerved lemmas, hits with free pericarps, and ligules with a 

line of hairs. These characteristics also are found in two other 

genera, Crypsis and Sporobolus. These three genera seem to 

share a common ancestor and probably should be the only New 

World members included in the subtribe Sporobolinae. Clayton 

and Renvoize (1986) included Lycurus, Muhlenbergia, and 

Pereilema in this subtribe; however, these genera belong in the 

Muhlenbergiinae. The genus consists of four species divided 

into two sections, each with two species (Thieret, 1966). 

Section Calamovilfa is found in moist to dry pine barrens and 

on the edge of swamps, whereas section Interior is found on 

sand dunes, sandy prairies, sandy river banks, and sandy flood 

plains. 

6. Chaboissaeu E. Fourn., Mex. P1. 2:112. 1886.-Type: 

Plants hermaphroditic or andromonoecious; annual or 

perennial; lacking stolons; lacking rhizomes. Flowering culms 

erect or decumbent (3-90 cm tall, often rooting at lower 

nodes); caespitose or not; glabrous. Leaves cauline; without 

auricles. Sheaths mostly shorter than internodes; with smooth 

margins (hyaline, often scarious); not ciliate. Ligule a 

membrane (margins decurrent). Leaf blades linear (1.2-20 cm 

long, 0.7-3.0 mm wide); flat, conduplicate, or involute; not 

pungent. Inflorescence a Danicle (1-28 cm long, 0.4-10 cm 

wide); exserted or partially included in upper sheath. Main axis 

smooth or scabrous. primary branches appressed to spreading 

from main axis; terminating in a spikelet; with appressed 

secondary branches. Pedicels glabrous; scabrous. Disarticulation above glumes; lemma and palea falling as a unit. Callus 

hairy or glabrous. Spikelets 1.8-4.7 mm long; solitary; 

laterally compressed (dark gray or plumbeous to grayish 

yellow); subsessile or pedicellate (pedicels 0.2-3 mm long). 

Glumes shorter or about equalling spikelets; more or less equal; 

scabrous; glabrous. First elume 1-nerved. Second glume 

shorter than lower lemma; awned or unawned; 1-nerved. 

Rachilla pronounced or not pronounced between florets; 

glabrous. Florets 1-3 Der spikelet. Sterile florets present or 

absent; above fertile florets. Lemma entire; awned, mucronate, 

or unawned (awn 0.2-6 mm long); hairy; pubescent (with 

minute, appressed hairs); scabrous; 3-nerved (sometimes 

obscurely so); chartaceous (mottled); with hairy nerves. Palea 

glabrous; extending or not extending into awns (awns up to 1.2 

mm long); chartaceous; scabrous. Lodicules truncate. Stamens 

3. Anther reddish purple or olivaceous plumbeous. Stigmas 2. 

Caryopsis terete. Base chromosome number of x = 8. 

DISTRIBUTION.-North America (Mexico) and South America (Argentina, Bolivia). Native to the New World. 

REmxxs.-Historically, Chaboissaea, sensu stricto, contained a single species, C. ligulata, ranging from northern 

Chihuahua to Distrito Federal, Mexico. Chaboissaea, although 

easily separated from Muhlenbergia, has traditionally been 

included in the latter genus by Hitchcock (1 9 13), Bews (1929), 

Conzatti (1946), and, more recently, Watson et al. (1985) and 

Clayton and Renvoize (1986). Sohns (1953) emended the 

description of C. ligulata and suggested the genus belonged in 

the Festuceae rather than in the Agrostideae, an unnatural 

assemblage of mostly single-flowered genera. Reeder and 

Reeder (1988) transferred two Mexican annual species, C. 

decumbens (Swallen) Reeder & C. Reeder and C. subbzj7ora 

(Hitchc.) Reeder & C. Reeder, from Muhlenbergia into 

Chaboissaea. Based on morphological, anatomical, and cytoChaboissaea ligulata E. Fourn. 
26 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

logical similarities, Peterson and Annable (1992) included a 

South American annual, C. atacamensis (Parodi) P.M. Peterson & Annable, in Chaboissaea. A revision of the genus and a 

hypothesized phylogeny based on morphological attributes is 

given in Peterson and Annable (1992). The four species of 

Chaboissaea differ from other eragrostoid genera in having 

gray to grayish yellow spikelets with one or two (occasionally 

three) florets per spikelet, the lower floret perfect and the upper 

floret staminate or sterile, and a base chromosome number of 

x = 8. All four species occur in dark, clayish soils in seasonally 

wet marshes, drainage ditches, and margins of ephemeral 

pools. Data from restriction site variation of chloroplast 

genomes suggest that Chaboissaea is most closely related to 

Muhlenbergia and is best placed in the subtribe Muhlenbergiinae along with Bealia, Blepharoneuron, Lycurus, and 

Pereilema (Duvall et al., 1994). Our evidence from morphology, biogeography, and soluble enzymes suggests that the 

genus arose in north-central Mexico, where three species still 

exist, and that the progenitor of C. atacamensis migrated to 

South America recently (Peterson and Annable, 1992; Peterson 

and Herrera A., 1996). 

7. Crypsis W.T. Aiton, Hortus Kew. 1:48. 1789 (non. 

Plants annual; lacking stolons; lacking rhizomes. Flowering 

culms erect, decumbent, or mat forming (3-40(-60) cm tall, 

much branched near base); not caespitose; glabrous. Leaves 

cauline; without auricles. Sheaths shorter than internodes; with 

smooth margins (membranous); not ciliate (few hairs at apex). 

Ligule a line of hairs. Leaf blades linear (2-5 cm long, 1-6 mm 

wide, papilose-hirsute); flat or involute; not pungent. Inflorescence a panicle (1-6 cm long, 2.5-8.0 mm wide, hemispherical 

to ovoid, cylindrical-spiciform); exserted or partially included 

in upper sheath (terminating main culms and also in axils of 

upper leaves, often partially enclosed by spathe-like sheaths). 

Main axis smooth. Primary branches appressed to main axis; 

terminating in a spikelet. Disarticulation below or above 

glumes; lemma and palea falling as a unit or falling separately. 

Callus glabrous. Spikelets 2.5-4 mm long; solitary; strongly 

laterally compressed; sessile or subsessile. Glumes shorter than 

or about equalling spikelets; more or less equal; scabrous; 

glabrous. First glume l-nerved. Second glume about same 

length as lower lemma; unawned; l-nerved. Florets 1 per 

spikelet. Lemma entire; unawned (acute, sometimes mucronate 

or short-awned); glabrous; scabrous (on keel); 1 -nerved; 

hyaline or membranous; with glabrous nerves. Palea glabrous; 

not extending into awns; hyaline; margins not enfolding fruit; 

smooth (rarely l-nerved). Lodicules absent. Stamens 2 or 3. 

Anther reddish purple. Stigmas 2. Fruit with free pericarp. 

Achene terete. Base chromosome number of x = 8 or 9. 

DISTRIBUTION.-North America, Central America, Africa, 

Europe, and Asia. United States (Northern Pacific Region, 

cons.).-Type: Cvpsis aculeata (L.) W.T. Aiton. 

Californian Region, Great Lakes Region) and Mexico. Introduced to the New World (represented by 3 naturalized species). 

REws.-The type species, C. aculeata, was first placed 

among the Cyperaceae by Linnaeus, who was no doubt mislead 

by the dilated or spathe-like upper leaf sheaths subtending the 

inflorescence (Lorch, 1962). Hubbard ( 1947) recognized the 

affiity of Cvpsis with Sporobolus by noting the apparent 

apomorphies of hits with a free pericarp, single-flowered 

spikelets, l-nerved lemmas, and ciliate ligules. These four 

characters clearly delineate the subtribe, Sporobolinae, of 

which Cvpsis is a member. The genus is represented in the 

western hemisphere by three naturalized species: C. alopecuroides (Phill. & Mitterp.) Schrad., C. schoenoides (L.) Lam., 

and C. vaginzjlora (Forsk.) Opiz. All three species are found in 

sandy to clayish soils around drying lake margins, rivers, and 

vernal pools (Hammel and Reeder, 1979). 

8. Daciyloctenium Willd., Enum. P1. Hort. Berol. 1029. 

1809.-Lectotype: Dactyloctenium aegvptium (L.) Willd. 

Plants annual or perennial (species introduced to New World 

annual); stoloniferous; lacking rhizomes. Flowering culms 

erect or mat forming (20-70 cm tall); caespitose; glabrous. 

Leaves cauline; without auricles. Sheaths shorter than internodes; with scabrous margins; not ciliate (glabrous to 

pustulate-villous). Ligule a membrane (often ciliolate). Leaf 

blades linear (3-25(-40) cm long, 2.5-12 mm wide); flat; not 

pungent; without thickened margins (papillose-hispid on 

margins). Inflorescence a panicle (2-7 cm long with 3-9 

primary branches); exserted. Main axis smooth. Primary 

branches digitate; spreading to reflexed; terminating b a bare 

&. Disarticulation above glumes (but not between florets); 

lemma and palea falling as a unit. Callus glabrous. Spikelets 

(2-)4-5(-8) mm long; solitary; strongly laterally compressed; 

sessile (closely imbricate in 2 rows on one side of 3-angled 

rachis). Glumes present (keeled, broad); shorter than spikelets; 

unequal; smooth; glabrous. First glume 1 -nerved. Second 

glume shorter than lower lemma; awned from below apex; 

1 -nerved. Rachilla pronounced between florets; glabrous. 

Florets (2-)3-6(-9) per spikelet. Sterile florets present; above 

fertile florets. Lemma entire; awned or mucronate; glabrous; 

smooth; 3-nerved (lateral nerves indistinct); membranous; with 

glabrous nerves. Palea glabrous; not extending into awns; 

membranous; margins not enfolding hit; smooth. Lodicules 

truncate. Stamens 3. Anther yellow. Stigmas 2. Fruit with free 

pericarp. Achene terete (suborbicular, tranversely rugose). Base 

chromosome number of x = 10 or 12. 

DISTRIBUTION.-North America, Central America, South 

America, Africa, Europe, Asia, and Australia. United States 

(Northern Pacific Region, Californian Region, Southwestern Region, Northern Plains Region, Central Plains Region, 

Texan Region, Southeastern Region, Midsouth Region, Great 

Lakes Region, North Atlantic Region, and Central Atlantic 
NUMBER 87 27 

Region), Mexico, and West Indies. South America (Uruguay, 

Chile, and Argentina). Introduced to the New World (one 

species, D. aegyptium, widespread in the New World). 

REms.-The genus consists of approximately 13 species 

native to Eurasia, Africa, and Australia. Besides the widespread 

D. aegyptium, D. aristatum Link, D. geminatum Hack., and D. 

sindicum Boiss have been reported from Mexico (Beetle, 

1987). The grain of D. aegyptium is sometimes harvested in 

India and Africa and has been reported to have an unpleasant 

taste and to cause gastroenteritis (Bor, 1960). Dactyloctenium 

is an easily recognized genus characterized by digitately 

arranged primary branches, each of which terminates in a 

flattened point without a spikelet. Although the leaf anatomy 

between Elewine and Dactyloctenium is quite disparate 

(Sanchez, 1974), a close relationship may still exist as both 

genera exhibit similar inflorescences and have hits with a free 

pericarp. It is not known whether the derivation of a free 

pericarp has occurred once or is the result of a parallel event, 

originating in these two genera and again in Calamovilfa, 

Crypsis, and Sporobolus and in Tetrachne and Uniola. There 

appears to be very little cpDNA variation between Sporobolus 

and Eleusine in a cursory sampling of these two genera (Duvall 

et al., 1994). This would suggest that the evolution of a free 

pericarp was a single event. 

9. Dusyochloa Willd. ex Rydb., F1. Colo. Agr. Exp. Sta. Bull. 

100: 18, 37. 1906.-Tpe: Dasyochlou pulchella (Kunth) 

Willd. ex Rydb. 

Plants perennial; stoloniferous (3-7 cm long, ascending, 

wiry); lacking rhizomes. Flowering culms erect or decumbent 

(4-10 cm tall, consisting of elongated internodes topped by 

fascicles of leaves that generally bend down and root, 

producing other culms); caespitose; glabrous. Leaves mostly 

basal; without auricles. Sheaths shorter than internodes; with 

smooth margins; ciliate (hairs up to 2 mm long). Linule a line 

of hairs (3-5 mm long). Leaf blades linear (2-6 cm long); 

involute (often curved); pungent; with thickened margins. 

Inflorescence a raceme or a panicle (1-2.5 cm long, 1-1.5 cm 

wide, clustered into a spatheate head, appearing white-wooly); 

partially included in upper sheath. Main axis smooth. Primary 

branches appressed to main axis; terminating in a spikelet; 

reduced to fascicle of spikelets. Pedicels glabrous; smooth. 

Disarticulation above glumes; lemma and palea falling as a 

unit. Callus glabrous. Spikelets 5-10 mm long; solitary; 

laterally compressed; pedicellate. Glumes more or less equal; 

smooth; glabrous. First glume l-nerved. Second glume longer 

than lower lemma; awned; 1 -nerved. Rachilla pronounced 

between florets; glabrous. Florets (4-)U ggr spikelet. 

Sterile florets present; above fertile florets. Lemma lobed or 

cleft (clefts 1-3 mm deep); awned ((1.5-)2.5-4 mm long); 

hairy; villous (conspicuously long-hairy near base); smooth; 

3-nerved; membranous; with hairy nerves. Palea hairy; extending into awns; membranous; margins not enfolding fruit; 

ciliate; smooth. Stamens 3. Anther yellow. Stigmas 2 

(plumose, sessile, or on short style). Caryopsis terete. Base 

chromosome number of x = 8. 

DISTRIBUTION.-NO~~~ America. United States (Southwestern Region, Northern Plains Region, Central Plains Region, 

and Texan Region) and Mexico. Native to the New World. 

REMARKs.-Dasyochloa is a monotypic North American 

genus (0. pulchella) that is distributed from central Mexico to 

the southwestern United States. It is a very common desert 

grass in creosote-tarbush scrub. The generic name, Dasyochloa, first appeared in the literature as a nomen nudum in 

Steudel ( 1840) under Uralepis Nutt. Rydberg ( 1906) validated 

Dusyochloa with an English description as part of a key; it has 

largely been regarded as a synonym of Erioneuron. Based on 

lemma apices and lateral nerves, Car0 (1981) placed all the 

South American species and assorted varieties of Erioneuron in 

Dasyochloa. Using anatomical characters, Sanchez (1983b) 

later recognized only a single species, D. pulchella. The blades 

of Dusyochloa have more abaxial and adaxial sclerenchyma 

development than those of Erioneuron. Valdes-Reyna (1985) 

also discussed the morphological, anatomical, and cytological 

differences of this genus with Erioneuron, and his results 

support recognition of Dasyochloa. The affinity of Dasyochloa 

with Erioneuron has long been known. Recent cpDNA 

analyses suggest that Dusyochloa is basal and shares a most 

recent common ancestor with Erioneuron and Munroa (Duvall 

et al., 1994). Similar silica deposition patterns in the lemma 

(Valdes-Reyna and Hatch, 1991) and a numerical analysis 

of morphological features (Phillips, 1982) also suggest that 

Dasyochloa, Erioneuron, and Munroa are closely related. 

10. Distichlis Raf., J. Phys. Chim. Hist. Nat. Arts 89:104. 

18 19.-Tpe: Distichlis maritima Raf., nom. illeg. (Uniola spicatu L., D. spicata (L.) Greene). 

Plants dioecious (rarely monoecious); perennial; lacking 

stolons (rarely stoloniferous); rhizomatous (well developed, 

with pronounced scales). Flowering culms erect or mat forming 

(10-30(-50) cm tall); caespitose; glabrous. Leaves cauline; 

distinctly distichous; without auricles. Sheaths longer than 

internodes; with smooth margins; ciliate or not ciliate. Ligule a 

ciliate membrane (erose-ciliolate and tipped with long, stiff 

hairs). Leaf blades linear (2-8 cm long, 1-3 mm wide, stiff); 

flat or involute (occasionally convolute); pungent. Inflorescence normally consisting of more than 3 SDikelets; a panicle 

(3-10 cm long, sometimes a raceme, rarely reduced to a single 

spikelet); exserted or fully included (staminate exserted, 

pistillate included among leaves). Main axis scabrous. Primary 

branches appressed to main axis; terminating in a spikelet; with 

appressed secondary branches. Pedicels glabrous; scabrous. 

Disarticulation above glumes (tardily); lemma and palea falling 

as a unit. Callus glabrous. Spikelets 6-18(-28) mm long; 
28 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

solitary; laterally compressed; pedicellate. Glumes shorter than 

spikelets; more or less equal; smooth; glabrous. First glume 

(1 -)3-5(-7)-nerved (lateral nerves often indistinct). Second 

glume shorter than lower lemma; unawned; 5-7(-9)-nerved 

(lateral nerves often indistinct). Rachilla pronounced between 

florets; glabrous. Florets (3-)5- 15(- 17) per spikelet. Sterile 

florets present; above fertile florets. Lemma entire; unawned; 

glabrous; smooth; (5-)7- 1 1 (-13)-nerved; coriaceous; with 

glabrous nerves. Palea glabrous; not extending into awns; 

membranous or chartaceous (staminate and pistillate, respec - 

tively); smooth. Lodicules truncate. Stamens 3. Anther yellow 

(tinged with purple). Stigmas 2. Caryopsis terete (brown). Base 

chromosome number of x = 10. 

DISTRIBUTION.-North America, Central America, South 

America (Ecuador, Bolivia, Chile, and Argentina), and 

Australia. Alaska, Canada, United States (Northern Pacific 

Region, Californian Region, Southwestern Region, Northern 

Plains Region, Central Plains Region, Texan Region, Southeastern Region, North Atlantic Region, and Central Atlantic 

Region) and Mexico. Native to the New World. 

REMARKS.-Distichlis includes about six species distributed 

on saline, alkaline, or gypsum flats of deserts or seashores. 

Most of the species are not very palatable but are often used as 

forage in some areas because they form the dominant cover. 

Rafinesque (1 8 19) first proposed Distichlis by separating it 

from Uniola and Festuca (Beetle, 1943). Because the species is 

rhizomatous and polymorphic, for nearly a century most 

botanists recognized only a single species. More recently, 

Beetle (1955) treated the various forms of D. spicata as 

separate varieties, some restricted to South America. Clayton 

and Renvoize (1986) placed Distichlis in the Monanthochloinae along with Allolepis, Jouvea, Monanthochloe, 

Reederochloa, and Swallenia. Perhaps the closest sisters to 

Distichlis are Monanthochloe and Reederochloa. Monanthochloe and Distichlis share distichously arranged leaves and, 

along with Reederochloa, enlarged bicellular microhairs that 

are sunken in the leaf epidermis (Soderstrom and Decker, 

1965). 

11. Eleusine Gaertn., Fruct. 1:7. 1788.-Lectotype: Eleusine 

coracana (L.) Gaertn. (see Nash in N.L. Britton and A. 

Brown, Ill. F1. N. U.S. ed. 2. 1:228. 1913). 

Plants annual or perennial; lacking stolons; rhizomatous. 

Flowering culms erect (10-85 cm tall, rarely decumbent); 

caespitose; glabrous. Leaves cauline; without auricles. Sheaths 

longer or shorter than internodes; with smooth margins; not 

ciliate (a few hairs and glands near margin). Liple a ciliate 

membrane. Leaf blades linear (5-25(-40) cm long, 2-6(-11) 

mm wide); flat; not pungent. Inflorescence a panicle (2-15 cm 

long, 3-6(-16) cm wide, of 1-lo(-17) spike-like primary 

branches); exserted. Main axis smooth. Primary branches 

digitate (more commonly subdigitate); spreading from main 

axis; terminating in a spikelet. Disarticulation above glumes; 

lemma and palea falling as a unit. Callus glabrous. Spikelets 

(4-)5-6(- 1 1) mm long; solitary; laterally compressed 

(strongly); sessile (in 2 rows on one side of a triangular branch). 

Glumes shorter than spikelets; unequal; scabrous; glabrous. 

First glume 1 -nerved. Second glume shorter than lower lemma; 

unawned; 3-5-nerved. Rachilla pronounced between florets; 

glabrous. Florets 5-15 per spikelet. Sterile florets present; 

above fertile florets. Lemma entire; unawned (sometimes 

mucronate); glabrous; scabrous (on keel); 3-5-nerved (lateral 

nerves very close to midnerve); membranous; with glabrous 

nerves. Palea glabrous; not extending into awns; membranous; 

margins not enfolding hit; scabrous. Lodicules acuminate. 

Stamens 3. Anther yellow. Stigmas 2. Fruit with free Dericarp 

(thin membranous pericarp). Achene terete (transversely 

rugose). Base chromosome number of x = 9. 

DISTRIBUTION.-North America, Central America, South 

America (Colombia, Venezuela, Guiana, Surinam or French 

Guiana, Ecuador, Peru, Brazil, Bolivia, Paraguay, Uruguay, 

Chile, and Argentina), Africa, Europe, Asia, Australia, and 

Pacific Islands. United States (Northern Pacific Region, 

Californian Region, Southwestern Region, Northern Plains 

Region, Central Plains Region, Texan Region, Southeastern 

Region, Midsouth Region, Great Lakes Region, North Atlantic 

Region, Central Atlantic Region, and Alaskan Region), 

Mexico, and West Indies. Native and introduced to the New 

World (one species described from Uruguay). 

REmms.-Eleusine is a predominantly African genus, 

with seven of its nine species occurring there (Phillips, 1972). 

One species, E. tristachya (Lam.) Kunth, is native in South 

America and is naturalized in North America and Africa. Three 

other species of Eleusine, E. coracuna, E. indica (L.) Gaertn., 

and E. multijlora Hochst. ex A. Rich., are naturalized in the 

New World. Finger millet (E. coracunu) is widely grown in the 

tropics and subtropics of the Old World for food and for 

making beer. Eleusine is an easily recognized genus characterized by digitate or subdigitately arranged primary branches, 

each of which terminates in a spikelet. As mentioned 

previously, Dactyloctenium is a possible sister to Eleusine, as 

both genera exhibit similar inflorescences, have hits with a 

free pericarp, and are of Old World origin. In a cursory 

sampling of genera in the Eragrostideae, there appears to be 

very little cpDNA variation among Eleusine, Erugrostis, 

Sporobolus, and Tridens (Duvall et al., 1994). 

12. Eragrostis Wolf, Gen. P1. 23. 1776; Gen. Sp. 63, 65. 

178 1 .-kctotype: Eragrostis minor Host (see P. 

Beauvois., Essai Agrost. 74. 1812; Ross, Acta Bot. Neerl. 

15:157. 1966). 

-- Plants hermaphroditic; annual or perennial; stoloniferous or 

lacking stolons; rhizomatous or lacking rhizomes. Flowering 

culms erect, decumbent, or mat forming (1-120 cm tall); 

caespitose or not; glabrous; with viscid or nonviscid internodes. Leaves cauline or basal; without auricles. Sheaths longer 
NUMBER 87 29 

or shorter than internodes; glandular or not; with smooth or 

scabrous margins; ciliate or not ciliate. Ligule a ciliate 

membrane or a line of hairs (rarely membranous). Leaf blades 

-- filiform to triangular (0.6-60 cm long, 0.1-12 mm wide); flat, 

conduplicate, or involute; pungent or not pungent. Inflorescence a panicle (0.4-50 cm long, 0.3-40 cm wide); exserted or 

partially included in upper sheath. Main axis glandular or not; 

smooth, scabrous, or hairy. Primary branches appressed, 

spreading, or divaricate from main axis; terminating in a 

spikelet. Primary branches with appressed or spreading 

secondary branches or reduced to a fascicle of spikelets. 

Pedicels glabrous; smooth or scabrous. Cleistogamous spikelets present or absent. Disarticulation above glumes; lemma 

and palea falling as a unit or usually falling separately. Callus 

glabrous. Spikelets 1-25 mm long; in clusters or solitary; 

laterally compressed or terete; sessile, subsessile, or pedicellate. Glumes shorter than spikelets; unequal or more or less 

equal; smooth or scabrous; glabrous. First glume 1-nerved 

(rarely 2- or 3-nerved). Second glume shorter than lower 

lemma; unawned; 1-nerved (rarely 2- or 3-nerved). Rachilla 

pronounced between florets; glabrous. Florets 3- 15(-30) per 

spikelet (rarely 2(-1)-flowered). Sterile florets present or 

absent; above fertile florets. Lemma entire; mucronate or 

unawned; glabrous; smooth or scabrous; 3(-5)-nerved (occasionally lateral nerves indistinct, rarely 5-nerved); hyaline, 

membranous, chartaceous, coriaceous, or indurate; with 

glabrous nerves. Palea glabrous or hairy; not extending into 

awns; hyaline, membranous, or chartaceous; ciliate or not 

ciliate; smooth or scabrous. Lodicules truncate. Stamens 2 or 3. 

Anther yellow or reddish purple. Stigmas 2. Caryopsis terete or 

laterally compressed. Base chromosome number of x = 10. 

DISTRIBUTION.-North America, Central America, South 

America (Colombia, Venezuela, Guiana, Surinam or French 

Guiana, Ecuador, Peru, Brazil, Bolivia, Paraguay, Uruguay, 

Chile, and Argentina), Africa, Europe, Asia, Australia, and 

Pacific Islands. Canada, United States (Northern Pacific 

Region, Californian Region, Southwestern Region, Northern 

Plains Region, Central Plains Region, Texan Region, Southeastern Region, Midsouth Region, Great Lakes Region, North 

Atlantic Region, Central Atlantic Region, and Alaskan Region), Mexico, and West Indies. Native or introduced to the 

New World. 

REMARKS.-~ragrostis, the largest genus in the tribe (350 

spp.), with about 120 species in the New World, was first 

published by Wolf (1 776). The validity of Wolfs publication is 

in question, and many workers consider the first generic 

description to have appeared in Beauvois (1812). This 

controversy was reviewed by Ross (1 966) and Bor (1968). The 

generic name is based on a Greek translation of a pre-Linnaean 

taxon referred to as gramen amoris, hence eros, god of love, and 

agrostis, a grass (Harvey, 1948). Many of the species presently 

placed in Eragrostis were at one time placed in Poa L., Briza 

L., andlor Megustachyu P. Beauv. Like other large genera, 

many segregates have been erected to emphasize distinctive 

features. In the New World, Rafinesque (1825) recognized 

Erochloe, based on E. spectabilis (Pursh) Steud.; Philippi 

(1 858) described the genus Macroblepharus based on E. 

ciliaris (L.) R. Br.; and Nash (1903) described Acamptoclados 

based on E. sessilispicus (Buckl.) Nash. Two genera, Diandrochloa De Winter (1 960) and Roshevitzia Tzvelev (1 968), have 

been based on E. japonica (Thunb.) Trin. Within Eragrostis 

the species limits are often overlapping, and few agrostologists 

have attempted to work out any suitable phylogenetic scheme. 

Based on spikelet disarticulation at maturity, Clayton, Phillips, 

and Renvoize (1 974) and Clayton and Renvoize (1 986) have 

arrived at a “first approximation to natural groups” and have 

presented a key to sections Psilantha, Eragrostis, Lappula, and 

Platystachya. Van den Borre and Watson (1994) investigated 

53 species of Erugrostis and found that anatomical characters, 

among others, support the recognition of two distinct groups: 

subgenus Eragrostis and subgenus Caesiae. In most native 

New World taxa the lemmas fall acropetally (from the base 

toward the apex) from the persistent rachilla, and with the 

paleas persitent on the rachilla. Due to the wide range in 

variation, the distinction among many of the species is difficult 

even for the experienced agrostologist. The best combination of 

characters used to discriminate this genus from other Eragrostideae is disarticulation of the lemma and palea occurring 

separtely, longitudinally bowed-out paleas with ciliolate keels, 

and 3-nerved, unawned lemmas. In a phenetic study of the 

tribe, Phillips (1982) aligned Eragrostis with five small, 

segregate genera that range from southern Africa to IndoMalasia: Desmostachya (Hook.) Stapf in Dyer, Eragrostiella 

Bor, Myriostachya (Benth.) Hook., Psilolemma Phillips, and 

Richardriella Effers & Kenn.-O’Byme. Biogeography supports the hypothesis that the genus arose in the Old World, 

particularly in southern Africa, where it is the most speciose. 

There also seems to be a possible relationship with Dactyloctenium, Eleusine, andlor Sporobolus because free pericarps 

have been found in a few Old World species. 

13. Erioneuron Nash, J.K. Small, F1. Southeast. U.S. 143, 

1327. 1903.-Type: Erioneuron pilosum (Buckl.) Nash. 

Plants perennial; stoloniferous or lacking stolons; lacking 

rhizomes. Flowering culms erect (10-65 cm tall); caespitose or 

not; glabrous. Leaves mostly basal; without auricles. Sheaths 

shorter than internodes; with smooth margins; ciliate. Ligule a 

ciliate membrane. Leaf blades linear (2-10 cm long, 1-2.5 mm 

wide); conduplicate; pungent or not pungent; with thickened 

margins. Inflorescence a Danicle (1.5-6 cm long, 1-3 cm wide, 

rarely a raceme); exserted. Main axis smooth. Primary branches 

appressed or spreading from main axis; terminating in a 

spikelet; with @pressed secondary branches. Pedicels 

glabrous; smooth. Disarticulation above glumes; lemma and 

palea falling as a unit. Callus hairy. Spikelets (6-)8-12(-15) 

mm long; solitary; laterally compressed; pedicellate. Glumes 

shorter or about equalling spikelets; unequal or more or less 
30 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

equal; smooth; glabrous. First glume 1-nerved. Second glume 

shorter or longer than lower lemma; unawned; 1-nerved. 

Rachilla pronounced between florets; glabrous. Florets (4-)& 

- 12(-20) per spikelet. Sterile florets present; above fertile 

florets. Lemma emarginate or lobed (0.3-2.5 mm deep); awned 

(1-4 mm long); hairy; pilose (densely pilose near base); 

smooth; 3-nerved; membranous; with hairy nerves. Palea hairy; 

not extending into awns; membranous; margins not enfolding 

fruit; ciliate; smooth. Lodicules adnate to palea; cuneate. 

Stamens 1 or 3 (monandrous condition common). Anther 

yellow. Stigmas 2. Caryopsis terete (glossy and translucent). 

Base chromosome number of x = 8. 

DISTRIBUTION.-North America and South America (Peru, 

Bolivia, and Argentina). United States (Southwestern Region, 

Northern Plains Region, Central Plains Region, and Texan 

Region) and Mexico. Native to the New World. 

REMARKS.-The genus consists of three species, E. avenaceum (Kunth) Tateoka (with four varieties), E. nealleyi 

(Vasey) Tateoka, and E. pilosum (with three varieties). 

Erioneuron was submerged within Tridens for many years 

(Hitchcock, 1913; Hitchcock and Chase, 1951; Pilger, 

1954), and only after morphological, anatomical, and cytological investigations did Tateoka (1961) revive Erioneuron. He 

also made the necessary new combinations and suggested 

affinities with Munroa, rather than with Tridens. Anton (1977) 

described the two species (E. avenaceum and E. pilosa) that 

occur in Argentina, and Valdes-Reyna (1985) discussed all the 

species in North America. As pointed out previously in this 

paper, the affinity of Dasyochloa with Erioneuron has long 

been known. Recent molecular studies suggest that Dasyochloa 

is a basal member of a clade containing Erioneuron and 

Munroa (Duvall et al., 1994). Cytologically, Dasyochloa and 

Erioneuron share a base chromosome number of x = 8. Based 

on morphological features (Phillips, 1982) and similar silica 

deposition patterns in the lemma (Valdes-Reyna and Hatch, 

199 l), Dasyochloa, Erioneuron, and Munroa appear to be 

closely related. 

14. Gouinia E. Foum. ex Benth., Gen. PI. 3:1178. 1883.- 

Lectotype: Gouinia polygama E. Fourn. (see Swallen, 

her. J. Bot. 22:32. 1935). 

Plants perennial; lacking stolons; rhizomatous or lacking 

rhizomes (short and knotty). Flowering culms erect (0.3-2(-3) 

m tall); caespitose; glabrous. Leaves cauline; without auricles. 

Sheaths longer or shorter than internodes; with scabrous 

margins (to scaberulous, rarely smooth); ciliate or not ciliate 

(pilose and papillose-pilose toward collar). Ligule a 

membrane or a ciliate membrane. Leaf blades linear (10-45 cm 

long, 5-20(-26) mm wide); flat or loosely involute; not 

pungent. Inflorescence a panicle (5-40(-50) cm long); 

exserted. Main axis scabrous. Primary branches spreading or 

divaricate from main axis (8-25 cm long, branches mostly 

simple, naked near base); terminating in a spikelet. Pedicels 

glabrous; scabrous. Disarticulation above glumes; lemma and 

palea falling as a unit. Callus hairy. Spikelets 8-15(-25) mm 

long; solitary; laterally compressed; subsessile or pedicellate. 

Glumes shorter than spikelets; unequal; scabrous (on keel); 

glabrous. First glume 1 -3(-5)-nerved. Second glume shorter 

than lower lemma; unawned; 3-5(-7)-nerved Rachilla pronounced between florets; glabrous. Florets 2-6 per spikelet. 

Sterile florets present; above fertile florets (uppermost floret 

rudimentary and awned). Lemma entire; awned; hairy; pilose or 

villous (densely silky ciliate below); scabrous; 3- or 5-nerved; 

membranous; with glabrous nerves. Palea glabrous; extending 

-- into awns; membranous; margins not enfolding fruit; ciliate or 

not (silky); scabrous. Lodicules truncate. Stamens 3. Anther 

reddish purple. Stigmas 2. Caryopsis terete. Chromosome 

number of n = 20. 

DISTRIBUTION.-Central America and South America (Brazil, Bolivia, Paraguay, and Argentina). Mexico and West 

Indies. Native to the New World. 

REms.-The genus consists of about 12 species ranging 

from Mexico in the north to Argentina in the south. In the past 

the taxonomic position of the species in Gouinia has lead to 

their placement in other genera in different subfamilies, such as 

Arundinaria Michx. (Bambusoideae), Bromus L. (Pooideae), 

Diplachne (Chloridoideae), Festuca L. (Pooideae), Leptochloa 

(Chloridoideae), and Triodia R. Br. (Chloridoideae). In 

addition to revising Gouinia, Swallen (1935) suggested that it 

may be most closely related to Leptochloa, an opinion held also 

by Clayton and Renvoize (1986). Turpe (1975) gave a 

historical account of the systematic position of Gouinia and a 

revision of the Argentinian species. Leptochloa and Gouinia 

are morphologically very similar, with two or more (up to 10) 

florets per spikelet, a pronounced rachilla between each floret, 

very unequal glumes, and a 3- or 5-nerved lemma. The lemmas 

are usually long awned, the callus hairy, and the sheath 

margins, glumes, and paleas scabrous in Gouinia. In Leptochloa the lemmas are unawned or short-awned, the callus 

glabrous, and the sheath margins, glumes, and paleas smooth. 

More recently, Ortiz (1991) recognized a new, monotypic 

genus, Schenckochloa, based primarily on the triangular shape 

of the rachilla (apex) and caryopsis in cross section. The 

rachilla in S. barbata (Hack.) J. Ortiz. is hardly triangular, in 

fact, it appears circular to elliptic as in other species of Gouinia. 

These two characters seem hardly sufficient to warrant generic 

status, because many of the other characters cited in the paper, 

i.e., number of glume nerves and number of lemmata1 nerves, 

as characteristic for Schenckochloa, also are seen in other 

species of Gouinia. Ortiz (1993) recently completed a revision 

of Gouinia in which he recognized 12 taxa, including nine 

species. Based on morphological differences in the spikelets, 

rachilla, lemma, callus, and caryopsis, Ortiz (1 993) suggested 

that G. barbata be excluded from Gouinia. He indicated that G. 

barbata has affinities with Leptochloa and Trichoneura but did 

not specify if this species warrants generic recognition. 
NUMBER 87 31 

15. Jouvea E. Fourn., Bull. SOC. Roy. Bot. Belgique 15:475. 

Plants dioecious; perennial; stoloniferous; rhizomatous 

(often with scaly buds). Flowering culms decumbent or mat 

forming (20-60 cm tall); caespitose; glabrous. Leaves cauline; 

without auricles. Sheaths shorter or longer than internodes; 

with smooth margins; not ciliate. Ligule a line of hairs. Leaf 

blades linear (1-15 cm long, 1-4 mm wide when flat); 

involute; pungent. Inflorescence consisting of 1 -many spikelets (single or in fascicles of 2-5 in pistillate inflorescences); a 

panicle (pistillate 2-3 cm long, staminate 2-6 cm long); 

exserted or fully included (cluster consisting of 2-5 pistillate 

spikelets embedded in sponge-like tissue of rachilla, only 

summit of florets free). Main axis smooth. Primary branches 

appressed to main axis; terminating in a spikelet. Primary 

branches with appressed secondary branches. Disarticulation 

above glumes; lemma and palea falling as a unit. Callus 

glabrous. Spikelets 8-30 mm long (15-40 mm long in 

staminate spikelets); in clusters (pistillate spikelets only); 

laterally compressed; sessile. Glumes present or absent 

(sometimes first glume absent in staminate spikelets, absent in 

pistillate); shorter than spikelets (in staminate spikelets); very 

unequal; smooth; glabrous. First glume nerveless. Second 

glume shorter than lower lemma; unawned; l-nerved. Rachilla 

pronounced between florets (surface hard); glabrous. Florets 

(3-)5-25 per spikelet. Sterile florets present; above fertile 

florets; homomorphic. Lemma entire; unawned; glabrous; 

smooth; 3-nerved; chartaceous; with glabrous nerves. Palea 

glabrous; not extending into awns; chartaceous; margins not 

enfolding fruit; smooth. Lodicules truncate. Stamens 3. Anther 

yellow or reddish purple. Stigmas 2 (embedded in hard spongy 

tissue of rachilla). Caryopsis terete. Base chromosome number 

of x = 10. 

DISTRIBUTION.-central America and Mexico. Native to the 

New World. 

REMARKS.-Jouvea is an endemic New World genus with 

two species, J. pilosa (Presl) Scribn. and J. straminea Foum., 

distributed from Central America to the Pacific coast of Mexico 

on coastal sand dunes and mud flats. The genus is characterized 

by an inflorescence that consists of two to five pistils embedded 

in a sponge-like tissue of the rachilla, with only the summit of 

the florets free. Clayton and Renvoize (1986) place Jouvea in 

the Monanthochloinae along with Allolepis, Distichlis, Monanthochloe, Reederochloa, and Swallenia. Perhaps the closest 

sister to Jouvea is Monanthochloe. Monanthochloe and Jouvea 

share distichously arranged leaves and the dioecious habit. 

1876.-Tfle: Jouvea straminea E. Foum. 

16. Leptochloa P. Beauv., Essai Agrost. 71. 1812.- 

Lectotype: Leptochloa virgata (L.) Beauv. (see Nash in 

N.L. Britton and A. Brown, Ill. F1. N. US. ed. 2. 1:229. 

1913). 

Plants annual or perennial; lacking stolons; lacking rhizomes. Flowering culms erect (30-150 cm tall); caespitose; 

glabrous. Leaves cauline; with sheath auricles or without 

auricles (sheath auricles in L. viscida (Scribn.) Beal). Sheaths 

longer or shorter than internodes; with smooth margins; not 

ciliate. Lirmle a membrane or a ciliate membrane. Leaf blades 

linear (5-45 cm long, 2-14 mm wide); flat (often inrolled on 

drying); not pungent. Inflorescence a panicle (10-50 cm long, 

with racemose primary branches along elongated, central, 

triquetrous main axis); exserted. Main axis scabrous. Primary 

branches not digitate (sometimes subdigitate); appressed or 

spreading from main axis (2-10 cm long); terminating in a 

spikelet; with @pressed secondary branches. Pedicels 

glabrous; scabrous. Cleistogamous spikelets present or absent 

(present in axils of lower sheaths in L. dubia (Kunth) Nees). 

Disarticulation above glumes; lemma and palea falling as a 

unit. Callus glabrous. Spikelets 1.2-7(-12) mm long; solitary; 

laterally compressed or terete; subsessile or pedicellate. 

Glumes shorter than spikelets; unequal; smooth, glabrous. First 

glume l-nerved. Second glume shorter than lower lemma; 

unawned; 1 -3-nerved. Rachilla pronounced between florets; 

glabrous. Florets 2-10 per spikelet (rarely 1). Sterile florets 

present; above fertile florets (upper floret reduced to small, 

awnless rudiment). Lemma entire, emarginate, lobed; awned, 

mucronate, or unawned; glabrous or hairy; pubescent; smooth; 

3-nerved; membranous; with glabrous or hairy nerves (puberulent). Palea glabrous; not extending into awns; membranous; 

margins not enfolding hit; smooth. Lodicules truncate. 

Stamens 2 or 3. Anther yellow or reddish purple. Stigmas 2. 

Fruit with adnate pericarp. Caryopsis dorsiventrally compressed or laterally compressed. Base chromosome number of 

x = 10. 

DISTRIBUTION.-NO~~~ America, Central America, South 

America (Venezuela, Brazil, Bolivia, Paraguay, Uruguay, and 

Argentina), Africa, Europe, Asia, Australia, and Pacific Islands. 

United States (Northern Pacific Region, Californian Region, 

Southwestern Region, Northern Plains Region, Central Plains 

Region, Texan Region, Southeastern Region, Midsouth Region, Great Lakes Region, North Atlantic Region, and Central 

Atlantic Region), Mexico, and West Indies. Native or introduced to the New World. 

REws.-Leptochloa sensu lato consists of about 45 

species worldwide, with 15 species occuning in the New 

World. Although Phillips (1982), McNeill (1979), and Nicora 

and Rugolo de Agrasar (1987) recognized Diplachne Beauv. as 

a separate genus, we agree with McVaugh (1983) that the 

number of florets, the size of the spikelets, and the position of 

the panicle-branches (Lea, secund or not secund), vary from 

plant to plant and that these hardly seem sufficient to indicate 

a generic difference. Based on a numerical analysis of 

morphological characters, Phillips (1 982) found that species 

placed in Diplachne and Leptochloa overlaped one another in 

a principal coordinates analysis. At this time it seems more 

appropriate to recognize a highly variable but possibly 

monophyletic assemblage as a single genus. The relationship of 
32 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Leptochloa with other genera in this tibe is problematical. In a 

restriction fiagment analysis of cpDNA using a smattering of 

New World genera (Duvall et al., 1994), Leptochloa (dubia) is 

a basal clade member, sharing a common ancestor with 

Scleropogon, Dasyochloa, Munroa, and Erioneuron. In a stict 

consensus tree produced by a bootstrap analysis, it does not 

form a particularly strong clade with the other genera and 

instead shares a common ancestor in a clade including the 

Muhlenbergiinae, the Munroinae, Scleropogon, Sporobolus, 

Eleusine, Tridens, Tripogon, and Eustachys Desv. It does share 

a parallel restriction site loss with the latter genus, which is not 

included in the Eragrostideae. 

17. Lycurus Kunth, Nov. Gen. Sp. 1:141. 1816.-Lectotype: 

Lycurus phleoides Kunth (Hitchcock, U.S.D.A. Bull. 

772:139. 1920). 

Plants perennial; lacking stolons; lacking rhizomes. Flowering culms erect (30-60 cm tall); caespitose; hairy; finely 

pubescent. Leaves cauline; without auricles. Sheaths shorter 

than internodes; with scabrous margins; ciliate. Ligule a 

membrane (truncate or broadly deltoid, acuminate, or 3- 

toothed). Leaf blades linear (4-10 cm long, 1-3 mm wide); flat 

or conduplicate; not pungent (apex mucronate or acuminate); 

with thickened margins. Inflorescence a panicle (3-10 cm 

long, 0.4-1.3 cm wide); exserted (usually some axillary 

inflorescences present). Main axis scabrous. Primary branches 

appressed to main axis; terminating in a spikelet. Pedicels 

glabrous; scabrous. Disarticulation above glumes (with secondary point of disarticulating at base of spikelet pair); lemma 

and palea falling as a unit. Callus glabrous. Spikelets 3-4 mm 

long; paired (lower spikelet short pedicellate, staminate, 

occasionally sterile, or rarely perfect, upper spikelet long 

pedicellate and perfect); terete; pedicellate (lower spikelet 

0.6-0.8 mm long, upper spikelet 1.2-1.6 mm long). Glumes 

shorter than spikelets; more or less equal; scabrous; hairy. First 

glume 2-3-nerved (with 2 awns, 3-7 mm long). Second glume 

shorter than lower lemma; awned (with single awn, 1.5-4 mm 

long); 1-2-nerved. Florets 1 per spikelet. Sterile florets present. 

Lemma entire; awned (2-8 mm long); hairy; pubescent; 

scabrous; 3-nerved; membranous to chartaceous; with glabrous 

nerves. Palea hairy (pubescent); not extending into awns; 

membranous; scabrous. Lodicules truncate. Stamens 3. Anther 

yellow or reddish purple. Stigmas 2. Caryopsis terete. Base 

chromosome number of x = 10. 

DISTRIBUTION.-North America, Central America, and 

South America (Colombia, Ecuador, Bolivia, and Argentina). 

United States (Southwestern Region and Southeastern Region), 

and Mexico. Native to the New World. 

REMARKS.-The genus was first described by Kunth (1 8 16) 

as containing two species, L. phalaroides Kunth and L. 

phleoides. Based on the presence of perfect, paired spikelets, 

Nuttall (1 848) described a monotypic genus, Pleopogon 

setosum Nutt. Recent studies by Reeder (1985) and Sanchez 

and Rugolo de Agrasar (1986) recognized three species, 

including L. setosus (Nutt.) C. Reeder. Lycurus can be 

separated from other members of the Eragrostideae by 

possessing paired spikelets, with the lower one usually 

staminate and the upper one perfect, a narrow, spiciform 

panicle, and 2- or 3-nerved and 2-awned first glume. Based on 

anatomical and morphological similarities, particularly the 

paired spikelets, Lycurus was suggested to be closely related to 

Aegopogon and Tragus in the Zoysieae (Sanchez and Rugolo 

de Agrasar, 1986). Sanchez and Rugolo de Agrasar (1986) also 

pointed out the anatomical similarity between Erioneuron and 

Lycurus. Pilger (1956) erected the subtibe Lycurinae, which 

included Pereilema as well. Hilu and Wright (1982), in a 

phenetic study of the Poaceae, placed Lycurus near Hilaria. 

Clayton and Renvoize (1986) took the traditional view and 

placed Lycurus in the subtibe Sporoboliinae along with 

Calamovil$a, Crypsis, Hubbardochloa Auquier, Muhlenbergia, 

Pereilema, Sporobolus, and Urochondra Hubbard. Based on 

restriction site variation of the chloroplast genome, Lycurus 

appears to be most closely allied with Muhlenbergia and the 

following members of the Muhlenbergiinae: Bealia, Blepharoneuron, Chaboissaea, and Pereilema (Duvall et al., 

1994). 

18. Monanthochfoe Engelm., Trans. Acad. Sci. St. Louis. 

1 :436. 1859.-Type: Monanthochloe littoralis Engelm. 

Plants dioecious; perennial; stoloniferous; (wiry, up to 10 cm 

long); rhizomatous (scaly). Flowering culms mat forming 

(erect, floriferous branches usually 8-15 cm tall); not 

caespitose; glabrous. Leaves cauline; distinctly distichous; 

without auricles. Sheaths longer than internodes; with smooth 

margins; not ciliate. Ligule a ciliate membrane. Leaf blades 

linear (0.5-1.5 cm long, 1-3 mm wide at main branch tips); 

conduplicate (and subulate); pungent. Inflorescence consisting 

__ of a single spikelet (singly in axils of fascicled leaves); partially 

included in upper sheath (appearing terminal and concealed by 

upper leaves). Disarticulation above glumes (pistillate spikelets disarticulating tardily at lower rachilla node); lemma and 

palea falling as a unit. Callus glabrous. Spikelets 5-10 mm 

long; solitary; laterally compressed; sessile. Glumes absent 

(rarely, 1 rudiment present). Rachilla pronounced between 

florets; glabrous. Florets 2-5(-7) per spikelet. Sterile florets 

present; above fertile florets. Lemma entire; unawned; 

glabrous; smooth; 7-9-nerved (indistinct); coriaceous or 

indurate (staminate and pistillate, respectively); with glabrous 

nerves. Palea glabrous; not extending into awns; coriaceous or 

indurate; smooth. Lodicules absent. Stamens 3. Anther yellow. 

Stigmas 2. Caryopsis terete (usually with rudimentary styles at 

base). Chromosome number unknown. 

DISTRIBUTION.-North America, Central America, and 

South America (Argentina). United States (Californian Region, 

Texan Region, and Southeastern Region), Mexico, and West 

Indies (Cuba). Native to the New World. 
NUMBER 87 33 

REMARKS.-Monanthochloe consists of two species With 

amphitropical, disjunct distributions that occur on seashores 

and inland salt, gypsum, or alkaline plains. Monanthochloe 

littoralis is found in North America and Cuba and M. acerosa 

(Griseb.) Speg. is restricted to south central Argentina (Parodi, 

1954; Villamil, 1969). The genus is characterized by having 

short, distinctly distichous leaf blades and a partially included 

inflorescence that consists of a single spikelet. Stebbins and 

Crampton (1961) were the first to recognize the affinity of 

Monanthochloe, Distichlis, and Jouvea, near the Old World 

maritime genus Aeluropus. Monanthochloe seems well placed 

in the Monathochloinae along with the other New World 

genera Allolepis, Distichlis, Jouvea, Reederochloa, and Swallenia. Perhaps the closest sister to Monanthochloe is Distichlis. 

Monanthochloe and Distichlis share distichously arranged 

leaves and, along with Reederochloa, enlarged bicellular 

microhairs that are sunken in the leaf epidermis (Soderstrom 

and Decker, 1965). 

19. Muhlenbergia Schreb., Gen. P1. 44. 1789.-Lectotype: 

Muhlenbergia schreberi J.F. Gmel., Syst. Nat. 2: 171. 

1791 (see Nash in N.L. Britton and A. Brown, Ill. F1. N. 

U.S. ed. 2. 1:184. 1913). 

Plants annual or perennial; lacking stolons (M. asperifolia 

(Nees & Meyen ex Trin.) Parodi occasionally stoloniferous); rhizomatous or lacking rhizomes. Flowering culms erect, 

decumbent, or mat forming (2-300 cm tall, compressed-keeled 

to rounded near base); caespitose or not; glabrous or hairy; 

pubescent, pilose, or villous; with glaucous internodes or with 

neither viscid nor glaucous internodes. Leaves cauline or 

mostly basal; with or without sheath auricles. Sheaths longer or 

shorter than internodes; with smooth or scabrous margins 

(hyaline, scarious, occasionally striate); ciliate or not ciliate. 

Ligule a membrane or ciliate membrane (often decurrent). Leaf 

blades filifom or linear (1-100 cm long, 0.1-12 mm wide); 

flat, conduplicate, or involute; pungent or not pungent; with or 

without thickened margins. Inflorescence a panicle (0.5-1 10 

cm long, 0.2-35 cm wide); exserted or partially included in 

upper sheath. Main axis smooth, scabrous, or hairy. Primary 

branches appressed, spreading, divaricate, or reflexed from 

main axis; terminating in a spikelet; with appressed or 

spreading secondary branches. Pedicels glabrous or hairy; 

pubescent, pilose, or villous; smooth or scabrous. Cleistogamous spikelets present or absent. Disarticulation below or 

above glumes (most commonly above); lemma and palea 

falling as a unit. Callus hairy or glabrous. Spikelets 0.5-8 mm 

long; solitary (paired in M brevis C.O. Goodding, M. 

depauperata Scribn., and M. diversiglumis Trin.); not subtended by sterile bristles; laterally compressed, terete, or 

dorsiventrally compressed; subsessile or pedicellate. Glumes 

present (first glume often rudimentary or lacking in M. 

schreberi and occasionally lacking in some spikelets of M. 

diversiglumis); shorter, about equalling, or much exceeding 

spikelets; unequal or more or less equal; smooth or scabrous; 

glabrous or hairy. First glume l-Znerved. Second glume 

shorter, about same length, or longer than lower lemma; awned 

or unawned; l-Cnerved. Florets 1 per spikelet (occasionally 

2- or 3-flowered in M. asperifolia and M. uniflora (Muhl.) 

Fern.). Lemma entire or emaryinate (lobed in M. argentea 

Vasey and M. lucida Swallen); awned, mucronate, or unawned 

(awns up to 40 mm long); glabrous or hairy; pubescent, pilose, 

or villous; smooth or scabrous; &nerved (sometimes obscurely 

so; 1 -nerved in M. palmirensis Grignon & Laegaard); hyaline, 

membranous, or chartaceous; with glabrous or hairy nerves. 

Palea glabrous or hairy; extending or not extending into awns; 

hyaline, membranous, or chartaceous; smooth or scabrous. 

Lodicules truncate. Stamens 3. Anther yellow, reddish purple, 

or olivaceous plumbeous. Stigmas 2. Caryopsis terete or 

laterally compressed. Base chromosome number ef xrlO 

(x = 9 in M.filifonnis (Thurb. ex Wats.) Rydb. and M. vaginata 

Swallen) . DISTRIBUTION.-NO~~~ America, Central America, South 

America (Colombia, Venezuela, Ecuador, Peru, Brazil, Bolivia, 

Chile, and Argentina), Asia, and Pacific Islands. Canada, 

United States (Alaskan Region, Northern Pacific Region, 

Californian Region, Southwestern Region, Northern Plains 

Region, Central Plains Region, Texan Region, Southeastern 

Region, Midsouth Region, Great Lakes Region, North Atlantic 

Region, Central Atlantic Region, and Alaskan Region), 

Mexico, and West Indies. Native to the New and Old Worlds. 

REms.-Muhlenbergia is the second largest genus and 

contains over 150 species in the New World. The genus was 

proposed by Schreber (1789) in honor of G.H.E. Muhlenberg, 

a Lutheran minister and pioneer botanist of Pennsylvania. 

Many agrostologists have erected segregate genera to emphasize critical features of this large and diverse genus. Desvaux 

(1 8 10) recognized the genus Podosemum based on the 

caespitose, open-panicled, and long-awned M. capillaris 

(Lam.) Trin. Beauvois (1812) described the genus 

Clomena based on the annual M. peruviana (Beauv.) Steud., 

and Presl (1830) described Epicampes based on M. robusta 

(Fourn.) Hitchc. Two relatives of M. schreberi (M. 

glomerata (Willd.) Trin. and M. andina (Nutt.) Hitchc.) were 

given generic status by Link (1 833), as Dactylogramma, and by 

Thurber (1 863), as Vaseya, respectively. Nuttall (1848) 

described the genus Calycodon based on the widespread and 

often important range grass M. montana (Nutt.) Hitchc. The 

only other generic name given to a species presently placed in 

Muhlenbergia is Crypsinna, described by Fournier (1 886) and 

based on M. macroura (Kunth) Hitchc. Hitchcock’s (1935a) 

transfer of many of these segregate genera to Muhlenbergia has 

been followed by most American and European botanists. The 

morphological characters that delimit the genus are spikelets 

with single perfect florets and hyaline, chartaceous, or 

membranous lemmas with three usually prominent nerves. 

These characters are, however, not at all unique in the 
34 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Eragrostideae and seem to be portrayed by about one-half of the 

genera in the tribe. 

The distribution of this genus is almost entirely New World, 

and only approximately eight of the 160 species of Muhlenbergia are known to occur in southern Asia. These southern Asian 

species of Muhlenbergia appear to be closely related to those 

species of the genus that inhabit the eastern portion of the 

United States and were referred to by Pohl(l969) as belonging 

to the subgenus Muhlenbergia. 

On the basis of anatomy, morphology, and cytology, 

Soderstrom (1 967) distinguished two subgenera (Muhlenbergia, Podosemum) and divided subgenus Podosemum into two 

sections, sect. Podosemum and sect. Epicampes. Soderstrom 

placed 42 species of Muhlenbergia that have partially sclerosed 

phloem of the primary vascular bundles into subgenus 

Podosemum. Two years later Pohl(l969) completed a revision 

of 12 closely related species that he believed represented the 

entire subgenus Muhlenbergia in North America. Using 

characteristics of the rhizome (possession of very short 

internodes with imbricated scales) and leaf blade (thin, flat 

blades with low lengtwwidth ratios), Pohl distinguished these 

species from others in the genus. These same characteristics, 

however, are seen in M. californica Vasey, a species of the 

mountains and valleys of southern California. Morden (1 985) 

and Morden and Hatch (1986, 1987, 1996) have investigated 

the M. repens (Presl) Hitchc. complex, which consists of six 

species in North and South America. Based on morphology, 

anatomy, cytology, and, in part, flavonoid chemistry, a revision 

of 29 species of Muhlenbergia has been completed (Peterson 

and Rieseberg, 1987; Peterson, 1988, 1989; Peterson, Annable, 

and Franceschi, 1989; Peterson and Annable, 1991). More 

recently a biosystematic study investigating the morphology 

and flavonoid chemistry of the M. montana complex (consisting of 14 species) has been completed (Herrera-Anieta and 

Bain, 199 1 ; Herrera-Anieta and Grant, 1993). 

Pilger (1 956) divided Muhlenbergia into eight sections 

within his monogeneric subtribe Muhlenbergiinae. Subsequent 

authors have agreed that Pilger’s treatment was phylogenetically uninformative and not particularly useful (Soderstrom, 

1967; Pohl, 1969; Morden, 1985; Peterson and Annable, 1991). 

The placement of this large genus within the Eragrostideae has 

long been problematical. Because Muhlenbergia posesses 

many of the characteristics of the entire tribe, alliances with 

many other genera have been suggested. It has most recently 

been placed in the Sporobolinae by Clayton and Renvoize 

(1986), along with Calamovilfa, Crypsis, Hubbardochloa 

Auquier, Lycurus, Pereilema, Sporobolus, and Urochondra 

C.E. Hubb. Hubbardochloa and Urochondra are restricted to 

Africa and will not be discussed herein, whereas Calamovi~a, 

Crypsis, and Sporobolus seem to represent a closely allied 

group based on the possesion of a free pericarp and 1-nerved 

lemmas. That leaves us with two, smaller segregate genera, 

Lycurus and Pereilema. Based on similar leaf anatomical 

characters and preliminary analysis of restriction site variation 

of the chloroplast genome, M. diversiglumis has been suggested to be more closely related to species of Pereilema than 

to other species of Muhlenbergia (Peterson, Annable, and 

Franceschi, 1989). Likewise, M. brevis C.O. Goodding and M. 

depauperuta Scribn. exhibit morphological features that suggest a close relationship with Lycurus. Mez (1921) indicated a 

relationship with Lycurus when he transferred M. shafneri E. 

Fourn. in Hemsl., considered to be a synonym of M. 

depauperata, to Lycurus. Muhlenbergia brevis and M. depauperata share many morphological features with Lycurus, most 

importantly spikelets borne in pairs; first glumes that are 

2-nerved and 2-awned; second glumes that are 1-nerved and 

awned; 3-nerved, acuminate, awned lemmas with short 

pubescence along the margins; and pubescent paleas. Perhaps 

these two species are intermediate between Muhlenbergia and 

Pereilema. Based on the lack of cork cells on the lemmata1 

surface, Blepharoneuron, Chaboissaea, Crypsis, Lycurus, 

Muhlenbergia, and Sporobolus have been suggested to form an 

allied group (Valdes-Reyna and Hatch, 199 1). Our recent data 

from restriction fragment variation of cpDNA supports 

inclusion of Blepharoneuron, Chaboissaea, and Muhlenbergia 

along with Bealia, Lycurus, and Pereilema in an expanded 

Muhlenbergiinae (Duvall et al., 1994). 

20. Munroa Torr., Pacif. Railr. Rep. vol. 4, pt. 5(4):158. 

1857.-Tge: Munroa squarrosa (Nutt.) Torr. 

Plants hermaphroditic or gynomonoecious (1 species in 

northern Argentina); annual; stoloniferous (2-8 cm long, 

bearing fascicles of leaves); lacking rhizomes. Flowering culms 

decumbent or mat forming (erect floriferous culms not over 15 

cm tall, internodes elongate, slender, reclining or arching, 

sometimes rooting at nodes); not caespitose; hairy; pubescent. 

Leaves mostly basal; without auricles. Sheaths shorter than 

internodes; with scabrous margins; ciliate (on upper margins 

and with tuft of long hairs on either side of collar). Ligule a line 

of hairs. Leaf blades linear (1-5 cm long, 1-2.5 mm wide, 

short and fascicled); flat or conduplicate; pungent; with 

thickened margins. Inflorescence a panicle (0.5-1 cm long, 

0.5-1 cm wide, spatheate head, panicle reduced to small cluster 

of 2-4 subsessile spikelets); fully included (almost hidden in 

fascicles of leaves at branch tips). Main axis scabrous. Primary 

branches appressed to main axis; terminating in a spikelet. 

Pedicels glabrous; scabrous. Disarticulation above glumes; 

lemma and palea falling as a unit. Callus glabrous. Spikelets 

7-10 mm long; in clusters; laterally compressed; subsessile or 

pedicellate. Glumes present or absent (first glume absent or 

reduced to a scale in terminal spikelet); shorter than spikelets; 

unequal or more or less equal (those of lower spikelet subequal, 

those of upper spikelet unequal); smooth; glabrous. First glume 

1-nerved. Second glume shorter than lower lemma; unawned; 

1 -nerved. Rachilla pronounced between florets; glabrous. 

Florets 2-10 per spikelet. Sterile florets present; above fertile 

florets; heteromorphic (lower spikelet sessile and upper 
NUMBER 87 35 

spikelets pedicellate and in a fascicle). Lemma emarginate or 

lobed; awned (0.5-3 mm long, lateral nerves occasionally 

excurrent as mucros); hairy (tuft of hairs halfway up margin); 

villous; scabrous; 3-nerved; membranous or coriaceous; with 

hairy nerves. Palea glabrous; not extending into awns; 

membranous; margins not enfolding fruit; smooth. Lodicules 

present or absent; truncate. Stamens 2 or 3. Anther yellow. 

Stigmas 2 or 3 (barbellate on long styles). Caryopsis 

dorsiventrally compressed. Base chromosome number of x = 7 

or 8. 

DISTRIBUTION.-North America, Central America, and 

South America (Peru, Bolivia, Chile, and Argentina). Canada, 

United States (Californian Region, Southwestern Region, 

Northern Plains Region, and Texan Region), and Mexico. 

Native to the New World. 

REMARKS.-Munroa consists of five species, M. squarrosa, 

the sole member of section Munroa in North America; M. 

andina Phil. and M. decumbens Phil., section Hemimunroa, in 

South America; and M. argentina Griseb. and M. mendocina 

Phil, section Apelytron, in Argentina (Anton and Hunziker, 

1978). Anton and Hunziker (1 978) suggested that M. squarrosa 

is the most primitive member of the genus with a trimerous 

androecium and combined reproductive features seen in the 

other four South American species. Species diversity is highest 

in the Atacama Puna and adjacent mountains where the four 

annual, South American taxa occur (Parodi, 1934). Parodi 

(1 934) indicated a close relationship among Blepharidachne, 

Dasyochloa pulchella, Munroa, and Triodia (= Erioneuron) 

avenaceum. Tateoka (1 96 1) suggested that Dasyochloa, Erioneuron, and Munroa were more closely related among 

themselves than they were to Tridens. Recent cpDNA analyses 

place Erioneuron and Munroa as sharing a common ancestor, 

whereas Dasyochloa is the next closest sister (Duvall et al., 

1994). Similar silica deposition patterns in the lemma 

(Valdes-Reyna and Hatch, 1991) and a numerical analysis 

of morphological features (Phillips, 1982) also suggests 

Dasyochloa, Erioneuron, and Munroa are closely related. The 

genus is named after William Munro (1 8 18- 1889), an English 

agrostologist. 

21. Neerugrostis Bush, Trans. Acad. Sci. St. Louis. 13:178. 

Plants dioecious; annual; lacking stolons; lacking rhizomes. 

Flowering culms decumbent or mat forming (creeping and 

rooting at nodes, floriferous tips 5-20 cm tall); not caespitose; 

glabrous or hairy; pubescent, pilose, or villous. Leaves cauline; 

without auricles. Sheaths shorter than internodes (mostly 

0.5-1.6 cm long); glandular; with scabrous margins; ciliate or 

not ciliate. Ligule a line of hairs (0.1-0.6 mm long). Leaf 

blades triangular (1-4 cm long, 1-4.5 mm wide); flat or 

conduplicate (arcuate, glabrous, or frequently pubescent on 

both surfaces); not pungent (apices somewhat stiffened). 

Inflorescence a panicle (1-3 cm long, 0.6-2.5 cm wide, dense 

1903.-Type: Poa reptans Michx. 

and spatheate); exserted or partially included in upper sheath. 

Main axis glandular; smooth or hairy. Primary branches 

appressed to main axis; terminating in a spikelet; with 

appressed secondary branches. Pedicels glandular or not; 

glabrous or hairy; pubescent, pilose, or villous; smooth. 

Disarticulation above glumes; lemma and palea falling separately. Callus glabrous. Spikelets 5-26 mm long; in clusters; 

laterally compressed; sessile, subsessile, or pedicellate. Glumes 

shorter than spikelets; unequal; smooth; glabrous or hairy. First 

glume l-nerved. Second glume shorter than lower lemma; 

unawned; 1-3 nerved. Rachilla pronounced between florets; 

glabrous. Florets 16-60 per spikelet. Sterile florets present; 

above fertile florets. Lemma entire (2-3.5 mm long); awned or 

mucronate; glabrous or hairy; pubescent, pilose, or villous; 

smooth; 3-nerved (nerves greenish); hyaline, in male spikelets 

membranous to chartaceous; with glabrous nerves. Palea 

glabrous or hairy; not extending into awns; hyaline (vestigial in 

female spikelets, less than l/2 length of lemma); margins not 

enfolding fruit; ciliate; smooth. Lodicules truncate. Stamens 3 

(1.4-2 mm long). Anther yellow. Stigmas 2. Caryopsis terete. 

Base chromosome number of x = 10. 

DISTRIBUTION.-North America and Central America. United States (Northern Plains Region, Central Plains Region, 

Texan Region, Southeastern Region, Midsouth Region, and 

Great Lakes Region) and Mexico. Native to the New World. 

REmRKs.-Hitchcock (1926) clarified the confusion between Eragrostis reptans (Michx.) Nees and E. hypnoides 

(Lam.) Britton, Sterns, & Pogg. Bush (1903) incorrectly 

based Neeragrostis on the latter and not the former and correct 

basyonym. Nicora (1962) revalidated the genus and listed 

specific morphological characters to differentiate between 

Eragrostis and Neeragrostis. The genus as presently interpreted includes two species: Neeragrostis reptans (Michx.) 

Nicora and N. contrerasii (Pohl) P.M. Peterson, comb. nov. 

(Eragrostis contrerasii R. Pohl, Iowa State J. Res. 5 1(3):323. 

1977). Neeragrostis can be separated from Eragrostis by its 

dioecious nature; style bases that are attached to the ovary at a 

single point, these somewhat persistent; dimorphic spikelets, 

with male plants having more hardened lemmas; a creeping 

habit (also present in E. hypnoides); bicellular microhairs with 

long basal cells; and dumbell-shaped silica bodies (also seen in 

E. tenella (L.) Beauv. and E. capilluris (L.) Nees). Koch (1978) 

and Pohl(l977) presented evidence for retaining these species 

in Eragrostis. Because Eragrostis appears to be a large 

polyphyletic assemblage, we believe that recognition of this 

small segregate genus is warranted. Based on similarities in leaf 

anatomy, Nicora (1962) suggested that Distichlis and Monanthochloe may be the closest relatives. 

22. Neesiochloa Pilg., Repert. Spec. Nov. Regni Veg. 48: 119. 

Plants annual; lacking stolons; lacking rhizomes. Flowering 

culms erect (15-30 cm tall); caespitose; glabrous. Leaves 

1940.-Type: Neesiochloa barbata (Nees) Pilg. 
36 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

cauline; without auricles. Sheaths shorter than internodes; with 

smooth margins; not ciliate. Ligule a ciliate membrane. Leaf 

blades linear (3-7 cm long, 2-3 mm wide, sometimes 

linear-lanceolate); flat; not pungent; with thickened margins 

(margins hispid, with tuberculate hairs). Inflorescence a raceme 

or panicle (4-10 cm long); exserted. Main axis glandular; 

smooth. Primary branches spreading from main axis; terminating in a spikelet; with spreading secondary branches. Pedicels 

glandular; glabrous; smooth. Disarticulation above glumes; 

lemma and palea falling as a unit. Callus hairy. Spikelets 6-9 

mm long; solitary; laterally compressed (broadly oblong or 

orbicular); pedicellate (0.5-2 cm long, capillary). Glumes 

shorter than spikelets; more or less equal; smooth; glabrous. 

First glume 1-nerved. Second glume about same length as 

lower lemma; awned; 1 -nerved. Rachilla pronounced between 

florets; hairy. Florets 6-1 2 Der spikelet. Sterile florets present; 

above fertile florets. Lemma emarginate (broadly truncate); 

awned; glabrous; smooth; 3-nerved; membranous; with hairy 

nerves (long ciliate). Palea hairy; not extending into awns; 

membranous; margins not enfolding hit; ciliate (with medial 

tuft of hairs); smooth. Lodicules acuminate. Stamens 3. Anther 

olivaceous plumbeous. Stigmas 2. Caryopsis dorsiventrally 

compressed. Chromosome number unknown. 

DISTRIBUTION.~outh America (Brazil). Native to the New 

World. 

REMARKS.-A monotypic South American genus known 

only from Brazil, where it inhabits damp, disturbed sites. Nees 

(1829) first described the type species in Calotheca Desv. 

Trinius (1831) placed this species in Briza L., and Kunth 

(1 833) aligned it with Chascolytrum Desv. Neesiochloa 

barbata is morphologically unique by having a distinctive 

emarginate, or broadly truncate, awned lemma with long ciliate 

nerves. Clayton and Renvoize (1986) mentioned that the 

caryopsis is similar to Erioneuron and placed this genus near 

Tridens and below a clade containing Blepharidachne, Erioneuron, and Munroa. Anatomically, the leaf blade has whitish 

margins and the lemma nerves are long ciliate, a characteristic 

of the Munroinae. More cytological and morphological data are 

needed to place this enigmatic genus in any other tribe than the 

unnatural Eragrostidinae. 

23. Neyraudia Hook., F1. Brit. India 7:305. 1896.-Tse: 

Neyraudia madagascariensis (Kunth) Hook. (= N. 

arundinacea (L.) Henrard). 

Plants perennial (reed-like); lacking stolons; rhizomatous. 

Flowering culms erect (1 -3 m tall); caespitose; glabrous. 

Leaves cauline; without auricles. Sheaths shorter than internodes; with smooth margins; not ciliate. Ligule a line of hairs. 

Leaf blades linear (1 -2 cm wide); flat (sometimes narrow and 

subinvolute, tapering to a filiform apex); not pungent. 

Inflorescence a panicle (typically more than 30 cm long, 

plumose, nodding, densely flowered); exserted. Main axis 

smooth. Primary branches spreading from main axis; terminating in a spikelet; with appressed secondary branches. Pedicels 

glabrous; scabrous. Disarticulation above glumes; lemma and 

galea falling separately. Callus glabrous. Spikelets 6- 10 mm 

long; solitary; laterally compressed; pedicellate. Glumes 

shorter than spikelets; unequal; smooth; glabrous. First glume 

1-nerved. Second glume shorter than lower lemma; unawned; 

1-nerved. Rachilla pronounced between florets; hairy. Florets 

2-5 per spikelet. Sterile florets present; below fertile florets 

(lower 1 or 2 sterile). Lemma a; awned (central awn 

recwed, lateral awn setaceously bidentate); hairy; long 

villous; smooth; 3-nerved; membranous; with hairy nerves 

(long ciliate on lateral nerves). Palea glabrous; not extending 

into awns; membranous; margins not enfolding fruit; smooth. 

hdicules acuminate. Stamens 3. Anther yellow. Stigmas 2. 

Caryopsis terete. Chromosome number unknown. 

DISTRIBUTION.-North America and Central America. United States (Southeastern Region) and Mexico. Introduced to the 

New World. 

RE MARKS.-^ Old World genus with only two species, 

superficially very similar to Phragmites Adans. (Clayton and 

Revoke, 1986). Neyraudiu exhibits typical Kranz or C4 leaf 

anatomy and embryo features that are common in the 

Chloridoideae; however, the occurrence of very slender 

arundinoid-like microhairs is unusual. Its affinity to other 

Eragrostideae is not known. Clayton and Renvoize (1986) only 

allude to a small clade with two other African genera, Triraphis 

R. Br. and Hubrochloa C.E. Hubb., as derived members. 

24. Pereilema J. Presl, Rel. Haenk. 1:233. 1830.-Tse: 

Plants annual; lacking stolons; lacking rhizomes. Flowering 

culms erect or decumbent (10-80 cm tall, often rooting at 

lower nodes, somewhat scaberulous roughened, often reddish 

purple); not caespitose; glabrous. Leaves cauline; with blade 

auricles (prominent and often ciliate). Sheaths longer or shorter 

than internodes; with smooth or scabrous margins; ciliate. 

Ligule a membrane (somewhat thickened, often brownish or 

purplish, less than 1 mm long). Leaf blades linear (3-22 cm 

long, 1-8 mm wide); flat; not pungent. Inflorescence a panicle 

(usually interrupted below, 3-20 cm long, 0.3-3 cm wide); 

exserted or partially included in upper sheath. Main axis hairy. 

Primary branches appressed or spreading from main axis; 

terminating in a spikelet; reduced to fascicle of spikelets. 

Pedicels glabrous or hairy; pilose or villous; smooth or 

scabrous. Disarticulation above or below glumes (occasionally 

between clusters of spikelets); lemma and palea falling as a 

unit. Callus hairy. Spikelets 1-3 mm long; in clusters; 

subtended ky sterile bristles (bristles usually scabrous but 

plumose in R ciliatum E. Foum.); terete (greenish to 

yellowish); sessile, subsessile, or pedicellate (0-2 mm long). 

Glumes shorter than spikelets; unequal or more or less equal; 

smooth; glabrous. First glume 1 -nerved. Second glume shorter 

than lower lemma; awned; 1-nerved. Florets 1 per spikelet. 

Pereilema crinitum J. Presl. 
NUMBER 87 37 

Sterile florets present (reduced to bristles); heteromorphic. 

Lemma entire; awned (0.7-3.5 cm long); hairy; pubescent or 

pilose; scabrous; 3-nerved; membranous (with visible papillae); with hairy nerves. Palea hairy; not extending into awns; 

membranous; scabrous. Lodicules truncate. Stamens 2 or 3. 

Anther yellow. Stigmas 2. Caryopsis laterally compressed. 

Base chromosome number of x = 10. 

DISTRIBUTION.-North America, Central America, and 

South America (Colombia, Venezuela, Guiana, Surinam, 

French Guiana, Ecuador, Peru, and Brazil). Mexico. Native to 

the New World. 

REMAms.-Presl (1 830) recognized Pereilema as a distinct 

genus and his concept has been narrowly interpreted by later 

authors. Kunth (1 833) described a species of Muhlenbergia 

from Brazil that Hitchcock (1927) later transferred to P. 

beyrichianum (Kunth) Hitchc. Pereilema ciliatum Foum. ex 

Hemsl. is native to Mexico, and P. crinitum occurs throughout 

the range of the genus. A new species, P. diandrum R.W. Pohl, 

apparently restricted to Costa Rica (Davidse and Pohl, 1992), 

brings the total to four in the genus. 

The genus can be separated from other members of the 

Eragrostideae by the sterile, bristle-like spikelets that subtend 

the fertile spikelets and by the prominent blade auricles that are 

usually ciliate. The species occupy seasonally moist sites along 

disturbed slopes and in partial openings in adjacent forest 

between 500-2100 m. Pereilema has been included in the 

Lycurinae by Pilger (1956), suggesting a relationship with 

Lycurus, and was included more recently by Clayton and 

Renvoize (1986) in the Sporobolinae along with Calamovilfa, 

Crypsis, Hubbardochloa, Lycurus, Muhlenbergia, Sporobolus, 

and Urochondra C.E. Hubb. Based on restriction site variation 

of the chloroplast genome, Pereilema seems allied with Bealia, 

Blepharoneuron, Chaboissaea, Lycurus, and Muhlenbergia, all 

members of the Muhlenbergiinae (Duvall et al., 1994). 

25. Redfiefdia Vasey, Bull. Torrey Bot. Club 14:133. 1887.- 

Type: Redfieldiaflexuosa (Thurb. ex A. Gray) Vasey. 

Plants perennial; lacking stolons; rhizomatous (long creeping or vertical). Flowering culms erect (50-130 cm tall); 

caespitose; glabrous. Leaves cauline; without auricles. Sheaths 

longer than internodes; with smooth margins; not ciliate. 

Ligule a line of hairs. Leaf blades filiform (16-75 cm long, 

1.5-5 mm wide and flexuous); involute; not pungent. 

Inflorescence a panicle (20-75 cm long, 4-25 cm wide, with 

flexuous, capillary branches and pedicels); exserted. Main axis 

smooth. Primary branches divaricate; terminating in a spikelet; 

with spreading secondary branches. Pedicels glabrous (sometimes with a few scattered hairs); smooth. Disarticulation above 

glumes; lemma and palea falling as a unit. Callus hairy (with 

long silky hairs). Spikelets (3-)5-7(-8) mm long; solitary; 

laterally compressed (dark gray or plumbeous); pedicellate 

(1-14 mm long). Glumes shorter than spikelets; very unequal; 

smooth; glabrous. First glume l-nerved. Second glume shorter 

than lower lemma; unawned; l-nerved (rarely 2-3-nerved). 

Rachilla pronounced between florets; glabrous. Florets 1-6 per 

spikelet. Sterile florets present; above fertile florets. Lemma 

entire; mucronate (slightly excurrent, forming 3 minute teeth, 

with lateral nerves); hairy; pubescent; smooth; 3-nerved; 

chartaceous; with glabrous nerves. Palea glabrous; not extending into awns; chartaceous; margins not enfolding fruit; not 

ciliate (tuft of hairs at base); smooth. Lodicules rounded. 

Stamens 3. Anther yellow or reddish purple. Stigmas 2. 

Caryopsis terete. Base chromosome number of x = 10 (cytologically atypical, 2n = 25 with a loosely synapsed bivalent and 

3 univalents). 

DISTRIBUTION.-North America. United States (Southwestem Region, Northem Plains Region, Central Plains Region, 

and Texan Region). Native to the New World. 

REms.-Thurber (1 863) described the only species 

recognized in the genus under Graphephorum Desv., an 

American segregate genus lying somewhere between Trisetum 

and Koeleria Pers. of the Pooideae, tribe Aveneae (Clayton and 

Renvoize, 1986). Vasey (1887b) considered the species to be 

distinct and created a genus in honor of J.H. Redfield, a curator 

of the Herbarium of the Philadelphia Academy of Natural 

Sciences. Vasey (1887b) mentioned that it resembled Triodia 

R. Br. (an endemic Australian genus), now treated as Tridens in 

the New World, but differed in many morphological features. 

The structure of the spikelets led Vasey to believe that R. 

j7exuosa seemed nearest to Festuca L. Other workers included 

Redfieldia in the Festucoideae, tribe Festuceae (Hitchcock, 

1935b, 1951; Sutton, 1973), and others have correctly aligned 

it with the Chloridoideae, tribe Eragrostideae (Pilger 1954; 

Reeder, 1957, 1976; Stebbins and Crampton, 1961; Decker, 

1964; Gould, 1968, 1975; Clayton and Renvoize, 1986). A 

second species, Redfieldia hitchcockii A. Camus, was described from Madagascar (Camus, 1926). Pilger (1956) first 

noticed that the placement of this species in Redfieldia was not 

appropriate. We agree with Camus that the spikelets between 

the two species are very similar; however, de Winter (1966) 

found this species to have danthonioid leaf anatomy and that it 

may prove to belong to the genus Styppeiochloa de Winter. 

Therefore, the generic and probably subfamilial placement of 

this enigmatic species needs reevaluation. 

The primary characters that can be used to differentiate 

Redfieldia from other members of the Eragrostideae are ligules 

with a dense line of hairs, a hairy, bearded callus, unequal 

glumes, 2-6-flowered spikelets, and 3-nerved, mucronate, 

chartaceous lemmas. Phillips (1982), in a phenetic analysis of 

the Eragrostideae, found Redfieldia to lie between Eragrostis 

and Tridens on a minimum spanning tree and principal 

coordinates plot, and Clayton and Renvoize (1986) reiterated 

her conclusion. Cytologically, R. flexuosa has been reported to 

have irregular meiosis at diakinesis and metaphase I, with 12 

bivalents and one univalent or 1 1 bivalents and three univalents 

(Reeder, 1971; 1976). It was suggested by Reeder (1976) that 

aneuploidy is occurring and that the base number for the genus 
38 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

is x = 10. Information from restriction site variation of the 

chloroplast genome (Duvall et al., 1994) aligns Redfierdia with 

members of the subtribe Muhlenbergiinae (Bealia, Blepharoneuron, Chaboissaea, Lycurus, Muhlenbergia, and Pereilema). Perhaps this species has arisen from hybridization 

between a member or an extinct ancestor of Eragrostis or 

Tridens (genera that have ligules with a dense line of hairs and 

2-many-flowered spikelets) and Muhlenbergia (membranous 

ligules and 1 -flowered spikelets), the maternal chloroplast 

donor. The inclusion of Redfieldia in the Muhlenbergiinae 

without further data seems premature. 

26. Reederochloa Soderstr. & H.F. Decker, Brittonia 16:334. 

1964.-Tve: Reederochloa eludens Soderstr. and H.F. 

Decker. 

Plants dioecious; perennial; stoloniferous; lacking rhizomes. 

Flowering culms erect (dimorphic; staminate culms 3-1 1 cm 

tall, pistillate culms 2-3.5 cm tall); caespitose; glabrous. 

Leaves mostly basal; without auricles. Sheaths longer than 

internodes; with smooth margins; ciliate (sparsely to densely 

pilose). Ligule a membrane. Leaf blades linear (1.5-4 cm long, 

0.2- 1 mm wide); involute; pungent. Inflorescence consisting 

__ of 2-3(-4) spikelets; a raceme (pistillate inflorescence 1-1.5 

cm long, 6-8.5 mm wide, staminate inflorescence 0.5-1.5 cm 

long, 5-8 mm wide); exserted or partially included in upper 

sheath (pistillate inflorescence hidden among leaves). Main 

axis smooth. Primary branches spreading from main axis; 

terminating in a spikelet. Pedicels glabrous; smooth. Disarticulation above glumes (tardily); lemma and palea falling as a unit. 

Callus glabrous. Spikelets 5-13 mm long; solitary; laterally 

compressed; pedicellate. Glumes shorter than spikelets; unequal; smooth; glabrous. First glume 2-8-nerved (indistinct). 

Second glume shorter than lower lemma; unawned; 3-8- 

nerved (indistinct). Rachilla pronounced between florets; 

glabrous. Florets 3-8 per spikelet. Sterile florets present; above 

fertile florets. Lemma entire; unawned; glabrous; smooth; 

6- 13-nerved (indistinct); coriaceous; with glabrous nerves. 

Palea glabrous; not extending into awns; chartaceous; smooth. 

Stamens 3, Anther olivaceous plumbeous. Caryopsis laterally 

compressed. Base chromosome number of x = 9 or 10. 

DISTRIBUTION.-North America. Mexico. Native to the New 

World. 

REMARKS.-Reederochloa is a monotypic, endemic Mexican genus restricted to a few alkaline flats in Durango and San 

Luis Potosi (Soderstrom and Decker, 1964). Morphologically, 

the genus is most similar to Distichlis and can be separated 

from the latter by possessing membranous ligules and a 

stoloniferous growth form. Clayton and Renvoize (1986) place 

Reederochloa in the Monanthochloinae along with Allolepis, 

Distichlis, Jouvea, Monanthochloe, and Swallenia. Distichlis, 

Monanthochloe, and Reederochloa share enlarged bicellular 

microhairs that are sunken in the leaf epidermis (Soderstrom 

and Decker, 1964). Perhaps the closest sisters to Reederochloa 

are Distichlis and Monanthochloe. 

27. Scferopogon Phil., hales Univ. Chile 36:205. 1870.- 

Plants dioecious or monoecious (rarely hermaphroditic); 

perennial; stoloniferous (creeping, 5-1 5 cm long); lacking 

rhizomes. Flowering culms erect or mat forming (10-25 cm 

tall); caespitose; glabrous. Leaves mostly basal; without 

auricles. Sheaths shorter than internodes; with smooth margins; 

not ciliate. Ligule a line of hairs. Leaf blades linear (2-6(-8) 

cm long, 1.5-2.5 mm wide); flat or conduplicate (sharply bent 

away from culm at base); pungent. Inflorescence a raceme or a 

panicle (pistillate inflorescence 10-15(-18) cm long, including awns; staminate inflorescence 3-7 cm long); exserted. 

Main axis scabrous. Primary branches appressed to main axis; 

terminating in a spikelet; with appressed secondary branches. 

Pedicels glabrous; scabrous. Disarticulation above glumes (but 

not between florets in pistillate spikelets); lemma and palea 

falling as a unit. Callus hairy (pistillate spikelets) or glabrous. 

Spikelets 20-40 mm long (staminate spikelets 10-24 mm 

long); solitaxv; laterally compressed or terete (rounded on back 

in pistillate spikelets); pedicellate. Glumes about equalling 

spikelets; more or less equal (glumes of pistillate spikelets 

subtended by glume-like bract, about as long as first glume); 

smooth; glabrous. First glume l-5-nerved. Second glume 

about same length as lower lemma; awned or unawned (awned 

on pistillate spikelets); 3-5-nerved (3-nerved in pistillate 

spikelets). Rachilla pronounced between florets; glabrous. 

Florets 2-5 Er sbikelet (occasionally l-flowered in male 

spikelets). Sterile florets present; above fertile florets (upper 

florets reduced to awns in pistillate spikelets). Lemma entire; 

awned or unawned (3 long, spreading terminal awns in 

pistillate spikelets, awns 4-10 cm long); glabrous; smooth; 

3-nerved; coriaceous; with glabrous nerves. Palea glabrous; not 

extending into awns; membranous or chartaceous; margins not 

enfolding hit; smooth. Lodicules present or absent (absent in 

pistillate spikelets); truncate. Stamens 3. Anther yellow. 

Stigmas 2. Caryopsis terete. Base chromosome number of 

x = 10 (2n = 40). 

DISTRIBUTION.-North America and South America (Chile 

and Argentina). United States (Californian Region, Southwestem Region, and Texan Region) and Mexico. Native to the New 

World. 

REwvxs.-This amphitropical, disjunct, monotypic genus 

is highly variable in its morphology and has been segregated 

into two species by Beetle (198 1). More recently, Reeder and 

Toolin (1 987) reevaluated Beetle's work and found no 

consistent morphological characteristics to differentiate two 

taxa. Clayton and Renvoize (1986) suggested that the genus is 

related to Tridens, perhaps through Sohnsia. 

In a cpDNA restriction site survey among a sample of New 

World Eragrostideae, the placement of Scleropogon is not well 

resolved (Duvall et al., 1994). Scleropogon does, however, 

appear to share a common ancestor with the Munroinae clade 

that includes Dasyochloa, Erioneuron, and Munroa. This is a 

very tentative result because not all genera of Eragrostideae 

me: Scleropogon brevifolius Phil. 
NUMBER 87 39 

were incorporated in this analysis. Peterson and Columbus 

(1997) investigated the soluble enzymes from populations 

occurring in North and South America, and it appears there is 

more genetic variation in North America. This would suggest a 

north to south migration pattern, where a few disseminules may 

have given rise to the South American populations that are 

fixed for certain alleles. 

28. Sohnsia Airy Shaw, Kew Bull. 18:272. 1965.--Type: 

Plants dioecious; perennial; lacking stolons; rhizomatous. 

Flowering culms erect (30- 100 cm tall); caespitose; hairy; 

pubescent. Leaves mostly basal; without auricles (rarely 

present as prolongation of sheath margin). Sheaths longer or 

shorter than internodes; with scabrous margins; not ciliate. 

Ligule a line of hairs (long ciliate near junction of leaf and 

sheath). Leaf blades linear (10-40 cm long, antrorsely scabrous 

on both surfaces); flat or involute (flexuous); not pungent. 

Inflorescence a panicle (7-20 cm long, spreading in anthesis, 

contracted with age); exserted. Main axis hairy (pubescent). 

Primary branches appressed or spreading from main axis; 

terminating in a spikelet; with appressed secondary branches. 

Pedicels hairy; pubescent; scabrous. Disarticulation above 

glumes; lemma and palea falling as a unit (tardily disarticulating between florets). Callus hairy. Spikelets 10-12 mm long 

(staminate spikelets 5-9 mm long); solitary; laterally compressed; pedicellate. Glumes shorter or about equalling 

spikelets; more or less equal; smooth; glabrous (slightly 

scabemlous on keel). First glume l-nerved. Second glume 

shorter or about same length as lower lemma; unawned 

(median nerve projecting beyond tip as small mucro); l-nerved. 

Rachilla pronounced between florets; hairy. Florets 3-5 per 

spikelet (3 in pistillate spikelets). Sterile florets present; above 

fertile florets. Lemma cleft; awned (3-awned from below apex); 

glabrous or hairy; pilose (pistillate plants); smooth, 3-nerved; 

membranous; with glabrous or hairy nerves. Palea glabrous; 

not extending into awns; membranous; margins not enfolding 

fruit; smooth. Lodicules truncate. Stamens 3. Anther reddish 

purple. Stigmas 2. Base chromosome number of x = lo? or 12 

(see Reeder, 1967). 

DISTRIBUTION.-North America. Mexico (endemic to San 

Luis Potosi). Native to the New World. 

REMAMs.-Fournier (1 877) originally described the genus 

Calamochloa as containing a single species, C. filifolia. Later, 

Airy Shaw (1965) transferred the species to a new genus, 

Sohnsia, because Calamochloa had previously been applied by 

Reichenbach (1828) to a different grass. Sohnsia is a 

monotypic, Mexican endemic known only from calcareous 

slopes at margins of dense thorn-scrub community in San Luis 

Potosi. The three-awned nature of the lemma in Sohnsia is a 

unique feature in the Eragrostideae. It lead Hubbard (1 934), 

Sohns (1956), and Roshevits (1980) to align it with the 

Pappophoreae, a related tribe in the Chloridoideae that has 

lemmas generally with 7- 19 awns. Anatomically, Sohnsia 

Sohnsiafilifolia (E. Fom.) Airy Shaw. 

exhibits eragrostoid features (Decker, 1964). Reeder (1967) 

found meiotic irregularities, such as formation of 10 bivalents 

and 4 univalents at diakinesis, that suggest a basic chromosome 

number of 10, a common number for the tribe. Clayton and 

Renvoize (1986) suggested that Sohnsia arose out of Tridens 

and then gave rise to Scleropogon, another dioecious member 

of the Eragrostideae. 

29. Sporobolus R. Br., Prodr. 169. 1810.-Lectotype: Sporobolus indicus (L.) R. Br. (see Nash in N.L. Britton and 

A. Brown, Ill. F1. N. U.S. ed. 2. 1:194. 1913). 

Plants annual or perennial; stoloniferous or lacking stolons; 

rhizomatous or lacking rhizomes (creeping). Flowering culms 

erect or mat forming (10-250 cm tall); caespitose (often 

forming large clumps); glabrous. Leaves cauline; without 

auricles. Sheaths longer or shorter than internodes; with smooth 

margins; ciliate or not ciliate. Ligule a line of hairs. Leaf blades 

filifom or linear (3-70 cm long, 1-15 mm wide at base); flat, 

involute, or terete; not pungent. Inflorescence a panicle (0.5-80 

cm long, 0.3-30 cm wide); exserted or partially included in 

upper sheath. Main axis smooth. Primary branches appressed, 

spreading, divaricate, or reflexed from main axis (with or 

without capillary branches); terminating in a spikelet; with 

appressed or spreading secondary branches. Pedicels glabrous; 

smooth. Cleistogamous spikelets present or absent (axillary 

when present). Disarticulation below or above glumes (commonly above first glume); lemma and palea falling as a unit. 

Callus glabrous. Spikelets 1-4(-7) mm long; solitary; terete; 

subsessile or pedicellate. Glumes shorter than spikelets; very 

unequal; smooth; glabrous. First glume 0- 1 -nerved. Second 

glume about same length as lower lemma; unawned; l-nerved. 

Florets 1 per spikelet. Lemma entire; unawned; glabrous and 

hairy; pubescent or pilose; smooth; l-nerved (3-nerved in S. 

palmeri Scribn.); membranous; with glabrous nerves. Palea 

glabrous; not extending into awns; membranous; margins not 

enfolding fruit; smooth. Lodicules present or absent; truncate. 

Stamens 2 or 3. Anther yellow, reddish purple, or olivaceous 

plumbeous. Stigmas 2. Fruit with free pericarp. Achene terete. 

Base chromosome number of x = 9. 

DISTRIBUTION.-North America, Central America, South 

America (Colombia, Venezuela, Guiana, Surinam or French 

Guiana, Ecuador, Peru, Brazil, Bolivia, Paraguay, Uruguay, 

Chile, and Argentina), Africa, Europe, Asia, Australia, and 

Pacific Islands. Canada, United States (Northern Pacific 

Region, Californian Region, Southwestern Region, Northern 

Plains Region, Central Plains Region, Texan Region, Southeastern Region, Midsouth Region, Great Lakes Region, North 

Atlantic Region, and Central Atlantic Region), Mexico, and 

West Indies. Native or introduced to the New World. 

REms.-Brown (1810) first erected Sporobolus to 

differentiate among the large number of species placed in 

Agrostis L. He thought Sporobolus differed from the latter 

genus by having a hairy throat, reduced ligules, and loose 

seeds. A very good review of the concepts and use of other 
40 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

generic names now placed in synonymy under Sporobolus are 

given in Baaijens and Veldkamp (1991). Hubbard (1947) 

recognized the affinity of Crypsis with Sporobolus by noting 

the apparent apomorphies of fruits with a free pericarp, 

1-nerved lemmas, and ciliate ligules. On the basis of 

anatomical differences, Duval-Jouve (1866) differentiated 

Crypsis and Sporobolus from other members of the old 

Agrostideae (1-flowered grasses). Based on a shared base 

chromosome number (x = 9) and size, Avdulov (193 1) placed 

Crypsis near Sporobolus. The possession of free pericarps, 

1 -nerved lemmas, and ciliate ligules clearly delineates the 

subtribe Sporobolinae, of which Crypsis is a member (Peterson 

et al., 1995). 

The genus is characterized by having single-flowered 

spikelets, 1-nerved lemmas, fruits with free pericarps, and 

ligules with a line of hairs. These characteristics also are found 

in two other genera, Calamovilfa and Crypsis. These three 

genera seem to share a common ancestor and probably should 

be the only New World members included in the subtribe 

Sporobolinae. Bentham (1881) first began to sort out the 

disparate array of genera placed in Agrostideae, sensu lato, by 

erecting the subtribe Sporobolinae (as “Sporoboleae”) with 

other genera, such as Coleanthus Seidl., Mibora Adans., and 

Phippsiu R. Br. More recently, Clayton and Renvoize (1 986) 

have included Muhlenbergia, Lycurus, and Pereilema in the 

Sporobolinae. Based on morphological similarity and shared 

cpDNA restriction site variation, these three genera belong in 

the Muhlenbergiinae (Duvall et al., 1994). The genus as 

presently circumscribed is very diverse, and a complete 

revision on a world-wide basis would be helpful in sorting out 

possible misplaced species. Within Sporobolus, Stapf (1 898) 

first divided the genus into two sections: Chaetorhaciu and 

Eusporobolus. Pilger (1956) then divided the latter section, 

which he elevated to subgenus Sporobolus, into six groups 

based on life form and characteristics of the glumes and 

panicles. Based on caryopsis morphology, Bor (1960) divided 

Sporobolus into five rather unnatural groups (Baaijens and 

Veldkamp, 199 1). Working on the Malesian species, Baaijens 

and Veldkamp (1 99 1) divided subgenus Sporobolus into five 

sections based on overall morphology, with special attention 

given to inflorescence branching. In the New World Sporobolus is represented by approximately 45 species that generally 

occur on marginal habitats, i.e., roadside to open prairies and 

savannahs. 

30. Sfeiruchne Ekman, Ark. Bot. 10(17):35. 191 l.-Tpe: 

Plants perennial; lacking stolons; rhizomatous (short, knotty 

base). Flowering culms erect (15-50 cm tall); caespitose; 

glabrous. Leaves cauline; without auricles. Sheaths shorter than 

internodes; with smooth margins; not ciliate. Ligule a line of 

hairs. Leaf blades linear (2-9 cm long, 1.5-2.5 mm wide); flat; 

not pungent. Inflorescence a panicle (2-7 cm long, ovate, short 

Steirachne diandra Ekman. 

pedunculate); exserted. Main axis scabrous. Primary branches 

spreading from main axis; terminating in a spikelet; with 

appressed secondary branches. Pedicels glabrous; scabrous. 

Cleistogamous spikelets present (at base or in upper leaf axils). 

Disarticulation above glumes; lemma and palea falling as a 

unit. Callus glabrous. Spikelets 7-12 mm long; solitary; 

laterally compressed; pedicellate. Glumes shorter than spikelets 

(subulate); more or less equal; smooth; glabrous. First glume 

1-nerved. Second glume shorter than lower lemma; unawned; 

1 -nerved. Rachilla pronounced between florets; (with 

apical tuft of hairs). Florets 6-13 Der spikelet. Sterile florets 

present; above fertile florets. Lemma entire; mucronate; 

glabrous; scabrous (midnerve setulose); 3-nerved (lateral 

nerves parallel to midnerve); membranous; with glabrous 

nerves. Palea glabrous; not extending into awns; membranous; 

margins not enfolding fruit; scabrous. Lodicules truncate. 

Stamens 2. Anther reddish purple. Stigmas 2. Caryopsis terete 

(narrowly elliptical, somewhat beaked near apex). Chromosome number unknown. 

DISTRIBUTION.-South America (Venezuela, Guyana, Surinam, French Guiana, and Brazil). Native to the New World. 

REmmS.4teirachne is a small genus with only two 

species: S. diandra and S. barbata (Trin.) Renvoize. They are 

primarily found growing in wet depressions in open savannah 

and cerrado habitats. Clayton and Renvoize (1 986) suggested 

that Steirachne may be most closely related to a group of seven 

small, Old WorldAustralian genera centered near Ectrosiopsis 

(Ohwi) Jansen. Anatomically, all have linear, elongated 

microhairs and triangular vascular bundles (Decker, 1964) 

rather than the bulbous microhairs that are more common in 

Eragrostis and other eragrostoid genera (Clayton and Renvoize, 1986; Judziewicz, 1991). Superficially, Steirachne can 

be differentiated from Eragrostis by the following combination 

of characters: florets disarticulating as a unit with segments of 

the rachilla, the later often with an apical tuft of hairs; florets 

with a setulose surface; florets loosely imbricate; cleistogamous spikelets present, often in the lower leaf sheaths; 

glumes persistent; and caryopses that are narrowly elliptical 

and somewhat beaked at the apex. 

31. Swulleniu Soderstr. & H.F. Decker, Madroiio 17:88. 

1963.-’Qqe: Swallenia alexandrae (Swallen) Soderstr. 

and H.F. Decker. 

Plants perennial; lacking stolons; rhizomatous. Flowering 

culms erect (25-60 cm tall, forming extensive masses, 1 m or 

more across, on sand dunes); caespitose; hairy; pilose (nodes 

lanate). Leaves cauline; not distinctly distichous (short and 

crowded); without auricles. Sheaths longer than internodes; 

with smooth margins; ciliate (villous at throat and collar). 

Lisle a line of hairs. Leaf blades linear (5-10 cm long, 3-5 

mm wide, strongly nerved); flat; pungent. Inflorescence a 

panicle (4- 10 cm long, narrow, branches short-appressed); 

exserted or partially included in upper sheath. Main axis 
NUMBER 87 41 

scabrous. Primary branches appressed to main axis; terminating 

in a spikelet; with appressed secondary branches. Pedicels 

hairy; pilose; scabrous. Disarticulation above glumes; lemma 

and palea falling as a unit. Callus hairy. Spikelets 10-15 mm 

long (nearly as wide); solitary; laterally compressed; pedicellate. Glumes about equalling spikelets; more or less equal; 

smooth; glabrous. First glume 7-nerved (some nerves faint). 

Second glume about same length as lower lemma; unawned; 

7- 1 1 -nerved (some nerves faint). Rachilla pronounced between florets; hairy. Florets 3-7 per spikelet. Sterile florets 

present; above fertile florets. Lemma entire; unawned; hairy; 

villous; smooth; 5-7-nerved; chartaceous; with hairy nerves. 

Palea hairy; not extending into awns; chartaceous; margins not 

enfolding fruit; ciliate; smooth. Lodicules truncate. Stamens 3. 

Anther reddish purple. Stigmas 2. Caryopsis terete; with 

persistent style bases. Caryopsis with relatively short and blunt 

style bases. Base chromosome number of x = 10. 

DISTRIBUTION.-North America. United States (Californian 

Region) (endemic to California sand dunes). Native to the New 

World. 

REMARKS.-The single species in this genus, Swallenia 

alexandrae, is known only from the Eureka Dunes in 

southeastern California, where it occurs in extensive masses, 

one meter or more in diameter, deeply embedded in siliceous 

sand (Henry, 1979). The species is listed as federally 

endangered in the United States and rare in California (Smith 

and York, 1984). Swallen (1950) recognized the unique 

features of this species and described it as a monotypic genus, 

Ectosperma Swallen. The generic name was invalid because it 

had been used in 1903 for an algal genus; therefore, Soderstrom 

and Decker (1963) named it after Jason R. Swallen (1903- 

199 l), a Smithsonian Institution (Washington, D.C.) agrostologist. Swallen (1950) suggested that Swallenia belonged in the 

Festuceae, possibly linked to the Aveneae. Anatomical work on 

Swallenia performed by Metcalf (1960) led Stebbins and 

Crampton (1 96 1) to place it in the subtribe Monanthochloinae 

(= Aeluropodinae), which includes Allolepis, Distichlis, Jouvea, Monanthochloe, and Reederochloa (Clayton and Renvoize, 1986). Swallenia shares the following characteristics 

with other members of the subtribe: 5-7-nerved, chartaceaous 

lemmas, and ligule a line of hairs. Swallenia can be separated 

from other members of the Monanthochloinae by possessing 

caryopses with short and blunt style bases and hermaphroditic 

flowers. 

32. Tetrachne Nees, F1. Africae Austr. 375. 1841.-Tpe: 

Plants perennial; lacking stolons; rhizomatous. Flowering 

culms erect (30-90 cm tall); caespitose; glabrous. Leaves 

cauline or mostly basal; without auricles. Sheaths shorter than 

internodes; with smooth margins; not ciliate (with few hairs at 

comers). Ligule a line of hairs. Leaf blades linear (5-20 cm 

long, 1-4 mm wide); flat or involute; not pungent. InfloresTetrachne dregei Nees. 

cence a panicle (8-20 cm long with 6-16 secund, racemose 

primary branches); exserted. Main axis smooth. Primary 

branches appressed to main axis; terminating in a spikelet. 

Pedicels glabrous (up to 0.5 mm long); smooth. Disarticulation 

above glumes; lemma and palea falling as a unit. Callus 

glabrous. Spikelets 3-6 mm long; solitary; strongly laterally 

compressed; subsessile (closely imbricate in 2 rows on 

racemose primary branches). Glumes present (keeled); shorter 

than spikelets; more or less equal; smooth; glabrous. First 

glume 1-nerved. Second glume shorter than lower lemma; 

unawned; 1 -nerved. Rachilla pronounced between florets; 

glabrous. Florets 5-6 Der spikelet. Sterile florets present; below 

fertile florets (2 lowest florets sterile and without paleas). 

Lemma entire (strongly keeled); unawned; glabrous; smooth; 

3-5-nerved (lateral nerves indistinct); membranous; with 

glabrous nerves. Palea glabrous; not extending into awns; 

membranous; margins not enfolding fruit; smooth. Lodicules 

truncate. Stamens 3. Anther yellow or reddish purple. Stigmas 

2. Fruit with free Dencarp (somewhat tardily). Achene terete. 

Base chromosome number of x = 10. 

DISTRIBUTION.-North America, South America (Argentina) and Africa. United States (Central Atlantic Region). 

Introduced to the New World (a monotypic genus from Africa, 

introduced as a forage grass in the United States and 

Argentina). 

RErvfmKs.-Etrachne can be differentiated from all other 

eragrostoid genera by possessing inflorescences with onesided, racemose primary branches along a central axis, each 

with two rows of spikelets, and the presence of sterile florets 

below the fertile ones. The laterally compressed spikelets with 

strongly keeled lemmas of Tetrachne suggested a close 

relationship with Uniola. Clayton and Renvoize (1986) 

suggested that Uniola is a basal member of a clade that gave 

rise to Tetrachne, Entoplocamia Stapf, and Fingerhuthia Nees, 

all members of the Uniolinae. Morphologically, Tetrachne is 

very similar to Eleusine and Dactyloctenium, members of the 

Eleusininae. All three genera share laterally compressed 

spikelets with strongly keeled lemmas, fruits with free 

pericarps, and spikelets that are two ranked along the primary 

inflorescence branches. These branches are arranged digitately 

or subdigitately in the Eleusininae and racemosely in Tetrachne. Whatever the case may be, Tetrachne seems somewhat 

centrally located between the Eleusininae and the Uniolinae. 

Etrachne dregei is native only in southern Africa and 

Pakistan, where it can form dense stands when grazed 

(Gibbs-Russell et al., 1990). 

33. Trichoneura Andersson, Kongl. Svenska Vetenskapsakad. 

Handl. 1853:148. 1855.-Tme: Trichoneura hookeri 

Andersson, nom. illeg. (Calamagrostis pumilia Ho0k.f.). 

Plants annual or perennial; lacking stolons; lacking rhizomes. Flowering culms erect (30-100 cm tall); caespitose; 

glabrous. Leaves cauline; without auricles. Sheaths shorter than 
42 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

internodes; with smooth margins (minutely scabrous); not 

ciliate. Ligule P membrane. Leaf blades linear (3-30 cm long, 

2.5-8 mm wide); flat (loosely involute on drying, acuminate); 

not pungent. Inflorescence a panicle (5-40 cm long, with 

unbranched racemose primary branches); exserted. Main axis 

scabrous (often puberulent). Primary branches spreading from 

main axis (occasionally appressed to main axis); terminating in 

a spikelet. Pedicels glabrous; scabrous. Disarticulation above 

glumes; lemma and palea falling as a unit. Callus glabrous. 

Spikelets 7-lo(-14) mm long; solitary; terete; subsessile or 

pedicellate (short pedicellate). Glumes about equalling spike- 

&; more or less equal; scabrous; glabrous. First glume 

1-nerved. Second glume about same length as lower lemma; 

mucronate or awned; 1 -nerved. Rachilla pronounced between 

florets; glabrous (a few hairs at top). Florets (4-)=(-9) per 

spikelet. Sterile florets present; above fertile florets. Lemma 

emarginate; awned; glabrous; scabrous; 3-nerved; membranous; with hairy nerves. Palea glabrous ( pilose between 

keels); not extending into awns; membranous; margins not 

enfolding fruit; smooth. Lodicules rounded. Stamens 3. Anther 

reddish purple. Stigmas 2. Caryopsis dorsiventrally compressed. Base chromosome number of x = 10. 

DISTRIBUTION.-North America, South America (Ecuador 

and Peru), Africa, Asia, and Pacific Islands. United States 

(Texan Region) and Mexico. Native to the New and Old 

worlds (8 species). 

REMARKS.-The following three species (four taxa) are 

autochthonous in the New World: Trichoneura elegans 

Swallen, I: lindleyana (Kunth) Ekman, I: Iindleyana var. 

albemarlensis (Rob. & Greenm.) J. Reeder, and I: weberbaueri Pilg. (Matthei, 1973; Nicora and Rugolo de Agrasar, 

1987). These species occur in open, usually sandy or stony 

habitats. Trichoneura is characterized by possessing emarginate lemmas with three prominent hairy nerves and spikelets 

with 5-8 florets. The genus is reminiscent of Erioneuron; 

however, we believe Trichoneura may be closely allied to, or 

derived from ancestors similar to Leptochloa and Gouinia, as 

suggested by Clayton and Renvoize (1986). 

34. Tridens Roem. 8z Schult., Syst. Veg. 2:34, 599. 1817.- 

Type: Tridens quinquefida (Pursh) Roem. & Schult., 

nom. illeg. (Poa seslerioides Michx.) (= I: jlavus (L.) 

Hitchc. (Poaflava L.)). 

Plants perennial; lacking stolons; rhizomatous or lacking 

rhizomes. Flowering culms erect (20- 170 cm tall); caespitose; 

glabrous. Leaves cauline; without auricles. Sheaths shorter than 

internodes; with smooth margins; not ciliate. Ligule a ciliate 

membrane or a line of hairs. Leaf blades linear (6-25 cm long, 

1-8 mm wide); flat or involute; not pungent. Inflorescence a 

panicle (5-35 cm long, occasionally a raceme); exserted. Main 

axis smooth or scabrous. Primary branches appressed, spreading, or divaricate from main axis; terminating in a spikelet; with 

spreading secondary branches. Pedicels glabrous; smooth or 

scabrous. Disarticulation above glumes; lemma and palea 

falling as a unit. Callus glabrous. Spikelets (3-)4-lo(-13) mm 

long; solitary; laterally compressed; pedicellate. Glumes 

shorter or about equalling spikelets; very unequal or subequal; 

smooth, glabrous. First glume I-nerved (rarely 3-nerved). 

Second glume shorter or about same length as lower lemma; 

unawned; 1 -3(-9)-nerved. Rachilla pronounced between 

florets; glabrous. Florets (3-)44(-16) per spikelet. Sterile 

florets present; above fertile florets. Lemma emarginate; 

mucronate (lateral nerves sometimes excurrent to a mucro); 

hairy; pubescent; smooth; 3-nerved; hyaline or membranous; 

with hairy nerves (hairy on nerves below, glabrous above, 

except I: albescens (Vasey) Woot. and Standl. occasionally 

glabrous below). Palea glabrous or hairy; not extending into 

awns; hyaline or membranous; margins not enfolding fruit; not 

ciliate (sometimes ciliate on keels); smooth. Lodicules adnate 

or not adnate to palea; rounded. Stamens 3. Anther reddish 

purple. Stigmas 2. Caryopsis dorsiventrally compressed. Base 

chromosome number of x = 10. 

DISTRIBUTION.-North America, Central America, South 

America (Bolivia and Argentina), and Africa. United States 

(Southwestern Region, Central Plains Region, Texan Region, 

and Southeastern Region) and Mexico. Native to the New and 

Old Worlds. 

REhbmKs.-Tridens consists of about 17 species endemic to 

the New World and one species from Angola (Tateoka, 1961; 

Clayton and Renvoize, 1986). The genus for many years was 

composed of a loose assemblage of species with a diverse 

geography. It was not until Burbidge (1946a, 1946b, 1953) 

found sufficient anatomical evidence to separate Triodia R. Br., 

an Australian endemic, from Tridens that the genus began to 

approach a phylogenetic unit or clade. Based on anatomical 

evidence, Burbidge ( 1946a, 1946b) thought Triodia would be 

better placed in the Danthonieae. For many years Erioneuron 

was included within Tridens (Hitchcock, 1913; Hitchcock and 

Chase, 1951; Pilger, 1954), and only after careful morphological, anatomical, and cytological investigations did Tateoka 

(1961) decide to use Nash’s (1903) Erioneuron for five taxa. 

The distinctive features of an emarginate lemma with a 

mucronate apex and hairy lateral nerves, 4-1 1 florets per 

spikelet, and ligules being either a ciliate membrane or a line of 

hairs, led Clayton and Renvoize (1986) to suggest that Tridens 

lies at the junction of several divergent lines. Our data on 

overall morphology suggests phenetic relationships with 

Erioneuron, Leptochloa, Munroa, Neesiochloa, Tnchoneura, 

and Tripogon. Erioneuron and Munroa have already been 

suggested to lie in the Munroinae, where the base chromosome 

number is either 7 or 8. In a cpDNA analysis involving 17 

genera of the Eragrostideae, I: jlavus and I: muticus (TOK.) 

Nash shared a common ancestor with and were basal to an 

extremely weakly supported clade containing Tripogon, Leptochloa, and Scleropogon (Duvall et al., 1994). 
NUMBER 87 43 

35. Triphis P. Beauv., Essai Agrost. 81. 1812,Type: 

Plants annual or perennial; lacking stolons; rhizomatous. 

Flowering culms erect (45-80 cm tall); caespitose; glabrous or 

hairy; pubescent (appressed-pubescent at nodes). Leaves 

cauline; without auricles. Sheaths shorter than internodes; with 

scabrous margins; not ciliate. Ligule a line of hairs. Leaf blades 

linear (4-15 cm long, 1-4 mm wide); flat or involute; not 

pungent. Inflorescence a panicle (3-1 1 cm long); exserted or 

partially included in upper sheath. Main axis scabrous. Primary 

branches spreading from main axis; terminating in a spikelet; 

with appressed secondary branches. Pedicels glabrous; scabrous. Cleistogamous spikelets present (in upper sheaths and at 

base of lower sheaths). Disarticulation above gIumes; lemma 

and palea falling as a unit. Callus hairy. Spikelets 6-10 mm 

long; solitary; laterally compressed; pedicellate. Glumes 

shorter than spikelets; unequal; scabrous (scabrous at midnerve 

with margins lacerate); glabrous. First glume 1 -nerved. Second 

glume about same length as lower lemma; unawned; l-nerved. 

Rachilla pronounced between florets; glabrous. Florets 2-4 Der 

spikelet (widely spaced on slender, long, rachilla internodes). 

Sterile florets present; above fertile florets. Lemma lobed (with 

notch 0.5-1 mm deep); awned (generally 1-2.5 mm long); 

hairy; villous; smooth; 3-nerved; membranous; with hairy 

nerves (lateral nerves conspicuously silky hairy). Palea hairy 

(silky villous on upper l/2); not extending into awns; 

membranous; margins not enfolding fruit; smooth. Lodicules 

truncate. Stamens 3 (none in cleistogenes). Anther reddish 

purple. Stigmas 2. Caryopsis dorsiventrally compressed (with 

reddish, striate pericarp). Chromosome number of n = 20. 

DISTRIBUTION.-North America and Central America. Canada, United States (Southwestern Region, Northern Plains 

Region, Central Plains Region, Texan Region, and Southeastern Region), Mexico, and Central America. Native to the New 

World. 

REMARKS.-Triplasis consists of three taxa in two species, 

T. americana, an annual with a short-awned lemma, I: 

purpurea (Walt.) Chapm., and T purpurea var. caribensis Pohl 

(1 972), a perennial with an awn longer than the lemma. Both 

species occur in sandy soils along streambanks and along the 

borders of forests. In a numerical analysis of morphological 

features, Phillips (1 982) found that Triplasis consistently 

formed a group within Tridens, sometimes in association with 

Trichoneura. Clayton and Renvoize (1986) suggested that 

Triplasis was derived from ancestors similar to Tridens. By 

possessing lobed lemma apices, a pronounced rachilla, and a 

chromosome number based on 10/20, Triplasis seems well 

placed near Leptochloa, Trichoneura, Tridens, and Tripogon. 

The occurrence of cleistagamous spikelets and disarticulating 

Triplasis americana P. Beauv. 

culms in Triplasis also is seen in Leptochloa, Gouinia, and 

Tridens (Pohl, 1980). 

36. Tripogon Roem. & Schult., Syst. Veg. 2:34, 600. 

1817.--Type: Tnpogon bromoides Roem. and Schult. 

Plants perennial; lacking stolons; rhizomatous. Flowering 

culms erect (5-55 cm tall); caespitose; glabrous. Leaves 

mostly basal (old sheaths persistent, shredded); without 

auricles. Sheaths shorter than internodes; with smooth margins; 

not ciliate (summit with minute tuft of white hairs). Ligule a 

ciliate membrane. Leaf blades filiform or linear (3-10 cm long, 

0.5-2.0 mm wide); involute; not pungent. Inflorescence a 

raceme (3- 10 cm long); exserted. Main axis scabrous (slender 

triangular). Rachis terminating in a spikelet. Disarticulation 

above glumes; lemma and palea falling as a unit. Callus 

glabrous. Spikelets 3-1 5(-25) mm long; solitary (spreading 

from main axis); laterally compressed; subsessile ( pedicels 

0.1-0.4 mm long). Glumes shorter than spikelets; unequal; 

scabrous (on keel); glabrous; about same length as lower 

lemma. First glume l-nerved. Second glume unawned; l(-3)- 

nerved. Rachilla pronounced between florets; glabrous. Florets 

(3-)5-12(-19) per spikelet. Sterile florets present; above 

fertile florets. Lemma -; awned (lateral nerves often 

excurrent as mucros); glabrous (except for tuft of hairs at base); 

scabrous (on central nerve and awn); 3-nerved; membranous; 

with glabrous nerves. Palea not extending into awns; membranous; margins not enfolding fruit; minutely ciliate; smooth. 

Lodicules truncate. Stamens 1-3. Anther yellow. Stigmas 2. 

Caryopsis terete. Base chromosome number of x = 10. 

DISTRIBUTION.-North America, Central America, South 

America, Africa, and Asia. United States (Texan Region), 

Mexico, and West Indies (Cuba). Native to the New World. 

REms.-In the New World, Tripogon consists of the 

widespread I: spicatus (Nees) Ekman and the more local I: 

ekmanii Nicora & Rugolo, from Paraguay and northeastern 

Argentina (30 species world-wide). The latter species differs 

from the former by having lanate vascular traces near the base 

of the culms and longer lemmas, paleas, rachillas, and anthers 

(Nicora and Rugolo de Agrasar, 1991). The genus seems to be 

most diverse in India, Burma, and Ceylon, where 13 species 

occur (Bor, 1960); however, there are at least eight species 

centered in Africa (Phillips and Launert, 1971). Although each 

species of Tripogon has a particular set of environmental 

requirements, T spicatus and quite a few others in the genus 

seem to prefer granitic substrates, often in the crevice of rocks. 

The genus is unique in the Eragrostideae in having an 

inflorescence that is a true raceme. Tripogon also differs from 

many other Eragrostideae by having lemmas with glabrous 

lateral nerves. By possessing emarginate lemma apices, a 

pronounced rachilla, and a chromosome number based on 10, 
44 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Tripogon seems well placed near Leptochloa, Trichoneura, and 

Tridens. Clayton and Renvoize (1986) suggested that Tripogon 

evolved from ancestors very similar to Leptochloa. 

37. Uniola L., Sp. P1. 71. 1753.-Lectotype: Uniola paniculata L. (see Nash in N.L. Britton and A. Brown, Ill. F1. N. 

U.S. ed. 2. 1:248. 1913). 

Plants perennial; stoloniferous; rhizomatous (long, thick). 

Flowering culms erect (0.5-2.5 m tall); caespitose; glabrous. 

Leaves cauline; not distinctly distichous (distichous at base in 

U. pitteri Hack.); without auricles. Sheaths longer than 

internodes; with smooth margins; not ciliate (except villous in 

throat and on margins, becoming glabrate in age). Ligule a line 

of hairs. Leaf blades linear (20-70 cm long, 8-15 mm wide, 

tough in texture); flat or conduplicate (coriaceous, tapering to a 

point); not pungent; without thickened margins (strongly 

ridged on adaxial surface). Inflorescence a panicle (10-60 cm 

long, narrow and dense); exserted. Main axis smooth. Primary 

branches appressed or spreading from main axis (branches 

drooping or nodding with age); terminating in a spikelet; with 

appressed or spreading secondary branches. Pedicels glabrous; 

smooth. Disarticulation below glumes. Callus glabrous. Spikelets 8-30(-50) mm long; solitary; strongly laterally compressed; pedicellate. Glumes shorter than spikelets; more or 

less equal; smooth; glabrous. First glume 3-5-nerved. Second 

glume shorter than lower lemma; unawned; 2-5-nerved. 

Rachilla pronounced between florets; glabrous. Florets (3-)& 

- 20(-30) per spikelet. Sterile florets present; above or below 

fertile florets (lower 2-6 empty and without paleas then sterile 

above fertile florets). Lemma entire; unawned (sometimes 

slightly mucronate); glabrous; smooth (keel sermlate); 3-9- 

nerved; coriaceous; with glabrous nerves. Palea glabrous; not 

extending into awns; chartaceous; margins not enfolding fruit; 

ciliate (to ciliolate); smooth. Lodicules truncate. Stamens 3. 

Anther yellow. Stigmas 2. Fruit with free pericarp. Achene 

terete. Base chromosome number of x = 10. 

DISTRIBUTION.-North America, Central America, West 

Indies, and South America (Colombia and Ecuador). United 

States (Texan Region, Southeastern Region, Midsouth Region, 

and Central Atlantic Region) and Mexico. Native to the New 

World. 

REMAmx-Yates (1966a, 1966b, 1967) investigated Uniola sensu lato and concluded that the genus was divisible into 

two distinct groups, one belonging to Chasmanthium, placed in 

the tribe Centotheceae, and the other in Uniola. Yates (1966b) 

further recognized Leptochloopsis Yates, a weakly supported 

segregate that was erected to show the affinity of U. virgata 

(Poir.) Griseb. and U. condensata Hitchc. to various 

species of Leptochloa. Uniola virgata and U. condensata are 

perhaps sister taxa but their placement in a separate genus at 

this time seems unwarranted. Uniola, as currently circumscribed, contains four species that are primarily centered along 

the Caribbean and Pacific coasts. The genus is characterized by 

strongly keeled, coriaceous lemmas, disarticulation of entire 

spikelets as a unit, and between 6-20 florets per spikelet. The 

laterally compressed spikelets with strongly keeled lemmas of 

Uniola suggested a close relationship with Tetrachne. Clayton 

and Renvoize (1 986) suggested that perhaps Uniola is a basal 

member of a clade that gave rise to Tetrachne and two other 

members of the Uniolinae. 

38. Vaseyochloa Hitchc., J. Wash. Acad. Sci. 23:452. 1933.- 

Plants perennial; lacking stolons; rhizomatous (slender, 

creeping or knotty). Flowering culms erect (50-100 cm tall); 

caespitose; glabrous. Leaves cauline; without auricles. Sheaths 

longer than internodes; with smooth margins; not ciliate. 

Ligule a ciliate membrane. Leaf blades linear (1 5-35 cm long, 

2-5 mm wide); flat or involute; not pungent. Inflorescence a 

panicle (5-20 cm long); exserted. Main axis scabrous. Primary 

branches spreading firom main axis (loosely contracted, at 

maturity branches drooping); terminating in a spikelet; with 

appressed or spreading secondary branches. Pedicels glabrous; 

scabrous. Disarticulation above glumes; lemma and palea 

falling as a unit. Callus hairy. Spikelets 10-18 mm long; 

solitary; laterally compressed (sometimes subterete); pedicellate. Glumes shorter than spikelets; very unequal; smooth; 

glabrous. First glume 3-5-nerved. Second glume shorter than 

lower lemma; unawned; 7-9-nerved. Rachilla pronounced 

between florets; hairy. Florets 6-1 1 per spikelet. Sterile florets 

present; above fertile florets. Lemma entire; unawned; hairy; 

pubescent or pilose (especially below); smooth; 7-9-nerved; 

chartaceous; with glabrous nerves. Palea glabrous; not extending into awns; chartaceous; margins not enfolding hit 

(splitting down to center at maturity); smooth. Lodicules 

truncate. Stamens 3. Anther reddish purple. Stigmas 2. 

Caryopsis terete (deeply concave on ventral side); with 

persistent style bases. Caryopsis with pronounced, sharppointed style bases. Chromosome number of n = 30,34. 

DISTRIBUTION,-North America. United States (Texan Region). Native to the New World. 

REMARKS.-A monotypic, North American genus, J! 

multinervosa is recorded from Texas and is probably present in 

Tamaulipas, Mexico (Gould, 1975). This species occurs on 

sands of river banks and coastal dunes and in sandy, open 

grasslands. Vasey (1 891 :235-236) originally described this 

enigmatic grass in another genus and stated, “I place this 

species doubtfully in Melica L., although it differs in several 

particulars from any species of that genus with which I am 

acquainted.” Hitchcock (1928) later transferred it to Triodia, at 

the time a genus containing most of the North American 

species of Tridens. Without any explanation, Hitchcock (1933) 

decided to place this species in its own genus, hence 

Vaseyochloa, after the original author. The relationship of 

Vaseyochloa to other members of the Eragrostideae is 

somewhat problematic. Clayton and Renvoize (1986) sugType: Vaseyochloa multinervosa (Vasey) Hitchc. 
NUMBER 87 45 

gested Vuseyochlou is related to Coeluchyrum Hochst. & Nees, 

an African genus of about eight species that has a caryopsis 

with a deeply concave ventral surface similar to Vaseyochlou. 

Based on phenetic characteristics, Neesiochloa, Nqruudiu, 

Steirachne, and Swalleniu are similar to Vuseyochlou by having 

pronounced rachillas that are hairy and having at least 6 florets 

per spikelet. In addition, Swulleniu has persistent style bases at 

the summit of the caryopsis, a character that also is found in 

Vaseyochlou. Besides Swallenia, which seems to clearly have 

affinities with other members of the Monanthochloinae, 

relationships among the other three species (Neesiochloa, 

Neyruudiu, and Steirachne) are not well understood. 

Classification 

Based primarily on morphological characteristics, we have 

attempted to place the genera of Eragrostideae into natural 

groups. We have included the naturalized genera along with the 

autochthonous genera, even though many of the remaining 

genera in each of the subtribes may be centered in other 

continents. By using results from our phenetic analysis and 

review of the literature (Peterson et al., 1995), especially on 

data from cpDNA restriction site comparisons (Duvall et al., 

1994), the New World Eragrostideae is appropriately divided 

into seven subtribes: Eleusininae, Eragrostidinae, Monanthochloinae, Muhlenbergiinae, Munroinae, Sporobolinae, and 

Uniolinae (see Table 1). Diagnostic, fully comparative descriptions for each subtribe are given in Peterson et al. (1995). 

Dactyloctenium and Eleusine are the New World representatives of the Eleusininae. An inflorescence with digitate primary 

branches is the diagnostic characteristic for this subtribe. 

Additional significant characters that define the Eleusininae 

include the presence of a free pericarp and a membranous 

ligule. The Eleusininae obviously arose in the Old World 

tropics, quite possibly in East Africa, where species diversity of 

Dactyloctenium and Eleusine is greatest. The few species 

represented in the New World of these two genera suggest 

migration from the Old World has occurred recently. 

The Eragrostidinae is, at best, an unnatural grouping of 

convenience, because the relationships among these 15 genera 

are poorly understood (Table 1). However, based on the full 

range of characters used herein, these genera are presently 

excluded from other subtribes. More than one floret per 

spikelet, fruit with an adnate pericarp, and base chromosome 

number of 10, 20, or 30 distinguishes the Eragrostidinae from 

the Eleusininae, Munroinae, Sporobolinae, and the Uniolinae. 

Important characters that can be used to separate the 

Eragrostidinae from most of the Monanthochloinae and 

Muhlenbergiinae include leaf arrangement (distichous in 

Monanthochloinae), sexuality (dioecious in Monanthochloinae, except Swalleniu), lemma texture (relatively thick 

in Monanthochloinae), and number of lemmata1 nerves 

(3-nerved in Muhlenbergiinae). No characters exclusively 

distinguish the Eragrostidinae from the Muhlenbergiinae. 

TABLE l.-Subtribal classification of the New World Eragrostideae. 

ELUSININAE Dumort., Anal. Fam. 63. 1829. w: Eleusine 

Dactyloctenium 

Eleusine 

Eragrostis 

Gouinia 

Leptochloa 

Neeragrostis 

Neesiochloa 

Neyraudia 

Redjieldia 

Scleropogon 

Sohnsia 

Steirachne 

Trichoneura 

Tridens 

Tnplasis 

Tripogon 

Vaseyochloa 

ERAGROSTIDINAE Resl, Rel. Haenk., 1:273. 1830. Type: Eragrostis 

MONANTHOCHLOINAE Potztal, Willdenowia 5472. 1969. Type: Monanthochloc? 

Allolepis 

Distichlis 

Jouvea 

Monanthochloe 

Reederochloa 

Swallenia 

MUHLENBERGIINAE Pilger, Nat. Pfl..-Fam. ed. 2, 14d:168. 1956. Type: 

Muhlenbergia 

Bealia 

Blepharoneuron 

Chaboissaea 

Lycurus 

Muhlenberp'a 

Pereilema 

nud.; Sida 16541. 1995. Qpe: Munroa 

Blepharidachne 

Dasyochloa 

Erioneuron 

Munroa 

Calamovilfa 

c?ypsis 

Sporobolus 

Tetrachne 

Uniola 

MUNROINAE Parodi ex P.M. Peterson, Gram. bonaer., ed. 4:28. 1946, nom. 

SFQROBOLINAE Benth., J. Linn. SOC. Bot. 19:30. 1881. m: Sporobolus 

UNIOLINAE Clayton, Kew Bull. 37:417. 1982. me: Uniola 

Eventually, as new data become available we suspect that many 

of these 15 taxa will be aligned within other current subtribes or 

placed within new, smaller monophyletic assemblages. 

The Uniolinae is a curious, small subtribe that includes only 

four genera worldwide (Clayton and Renvoize 1986), three 

distributed in Africa and Uniola centered along the subtropical 

and tropical coastal regions of North and Central America. The 

presence of 5-20 florets per spikelet, fruit with a free pericarp, 
46 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

and ligule a line of hairs are characters, when used in 

combination, that serve to distinguish the Uniolinae from the 

other subtribes. Characters of secondary significance include a 

3-9-nerved lemma, primary inflorescence branches racemose 

or paniculate, and lemma entire at the apex. The Uniolinae 

shows some affinities with the Eleusininae because both 

subtribes contain species with free pericarps, laterally flattened 

spikelets, and spikelets that are two-ranked along primary 

inflorescence branches. 

Calamovilfa, Cvpsis, and Sporobolus are the New World 

members of the Sporobolinae, which is exclusively defined by 

the presence of a 1-nerved lemma. Secondary diagnostic 

characters include one floret per spikelet and a line of hairs for 

a ligule. The Sporobolinae are closely linked to the Eleusininae 

and Uniolinae, as all three subtribes possess fruits with free 

pericarps. Our analysis does not indicate a close affinity 

between the Muhlenbergiinae and the Sporobolinae even 

though both have a one-flowered spikelet. Origin of the 

Sporobolinae probably lies in Africa or the Eastern Mediterranean, where species diversity is greatest. There are at least 39 

indigenous species of Sporobolus from southern Africa 

(Gibbs-Russell et al., 1991). 

Allolepis, Distichlis, Jouvea, Monanthochloe, Reederochloa, 

and Swallenia are the New World members of the Monathochloinae (Table 1). For most taxa, the presence of 

distichous leaf arrangement, thick textured lemmas, and the 

dioecious habit distinguishes this tribe. Secondary diagnostic 

characters include florets 2-25 per spikelet, fruit with an 

adnate pericarp, and lemmas entire at the apex. Numerous 

morphological and anatomical adoptions, i.e., distinctly distichous leaf arrangement and bicellular microhairs with enlarged 

bases, are found in some members of this subtribe. These 

adaptations are in direct response to the environment because 

most of the species occur in saline habitats. Based on our 

phenetic analyses and those by Soderstrom and Decker (1963, 

1964, 1965), the Monanthochloinae seems to be a good 

monophyletic unit. The Monanthochloinae is primarily New 

World in distribution; only Aeluropus Trin. is restricted to the 

Mediterranean, northern China, Ethiopia, and Sri Lanka. 

The distribution of the Muhlenbergiinae is almost entirely 

New World; only approximately eight of the 160 species of 

Muhlenbergia are known to occur in southern Asia. The six 

genera of the Muhlenbergiinae (Bealia, Blepharoneuron, 

Chaboissaea, Lycurus, Muhlenbergia, Pereilema) are charac - 

terized by 1-3 florets per spikelet, 3-nerved lemmas, true 

caryopses, and a base chromosome number of 8 or 10. These 

characters do not adequately distinguish the Muhlenbergiinae 

from the Munroinae. The Munroinae, however, always has 

2-12 florets per spikelet and the lemma apex is usually 

emarginate to cleft, whereas the Muhlenbergiinae usually has a 

single floret per spikelet and the lemma apex is mostly entire. 

Evidence from molecular data supports this subtribe as being 

monophyletic (Duvall et al., 1994). 

The Munroinae consists exclusively of the following New 

World genera: Blepharidachne, Dasyochloa, Erioneuron, and 

Munroa (Peterson et al., 1995). Diagnostic characteristics of 

the subtribe include lemmas with emarginate to cleft apices and 

a base chromosome number of x = 7 or 8. Molecular studies 

support the conclusion that the Munroinae evolved from a 

common ancestor (Duvall et al., 1994). 
Literature Cited 

Airy Shaw, H.K. 

1965. Diagnoses of New Families, New Names etc. Kew Bulletin, 18:272. 

Anton, A.M. 

1977. Notas criticas sobre Gramineas de Argentina. Kurtziana, 1051-67. 

Anton, A.M., and A.T. Hunziker 

1978. El genero Munroa (Poaceae): Synopsis morfologica y taxonomica. 

Boletin de la Academia Nacional de Ciencias Cordoba, 52: 

229-252. 

Avdulov, N.P. 

1931. Karyo-systematsche untersuchungen der Familie Gramheen. Bulletin of Applied Botany, Genetics, and Plant Breeding, supplement 

44:l-428. [English translation, 1975, at US.] 

1991. Sporobolus (Gramineae) in Malesia. Blumea, 35393-458. 

18 12. Essai d ‘une nouvelle Agrostographie, ou nouveata genres des 

Graminees, avec figures representant les caractires de tous les 

genres. 182 pages. Paris. 

Beetle, A.A. 

1943. The North American Variations of Distichlis spicata. Bulletin of the 

Torrey Botanical Club, 70:638-650. 

1955. The Grass Genus “Distichlis.” Revista Argentina de Agronomia, 

I98 I. Noteworthy Grasses from Mexico, IX. Phytologia, 49:33-43. 

1987. Noteworthy Grasses from Mexico, V. Phytologia, 37:317-407. 

Bentham, G. 

1881. Notes on Gramineae. Journal of the Linnean Sociev, Botany, 19: 

Bews, J.W. 

1929. 

Baaijens, G.J., and J.F. Veldkamp 

Beauvois, P.B. 

22:86-94. 

14-134. 

The Worlds’s Grasses: Their Diflerentiation, Distribution, Economics, and Ecology. 408 pages. New York: Longmans, Green, and 

Company. 

Bor, N.L. 

1960. The Grasses of Burma, Ceylon, India. and Pakistan (Excluding 

Bambuseae). 767 pages. Oxford: Pergamon Press. 

1968. Gramineae. In C.C. Townsend, E. Guest, and A. Al-Rawi, editors, 

Flora of Iraq, 9: 588 pages. Bagdad: Ministry of Agriculture. 

Brown, R. 

18 10. Prodromus Florae Novae Hollandiae 

Burbidge, N.T. 

1946a. Foliar Anatomy and the Delimitation of the Genus Triodia R. Br. 

Blumea, supplement 3:83-89. 

1946b. Morphology and Anatomy of the Western Australian Species of 

Triodia R. Br., 11: Internal Anatomy of Leaves. Transactions ofthe 

Royal Society of South Australia, 70:221-233. 

1953. The Genus Triodia R. Br. (Gramineae). Australian Journal of 

Botany, 1 : 121-1 84. 

Bush, B.F. 

1903. A New Genus of Grasses. Transactions of the Academy of Sciences, 

St. Louis, 13:175-178. 

Camus, A. 

1926. Le genre Redfieldia a Madagascar. Bulletin, Societe Botanique de 

France, 73: 1023-1024. 

Caro, J.A. 

198 1. Rehabilitation del genero Dasychloa (Gramineae). Dominguezia, 

2:1-17. 

Clayton, W.D., S.M. Phillips, and S.A. Renvoize 

1974. Gramineae (part 2). In R.M. Polhill, editor, Flora of Tropical East 

Africa, pages 177-450. Rotterdam: A.A. Balkema. 

Clayton, W.D., and S.A. Renvoize 

1986. Genera Graminum, Grasses of the World. Kew Bulletin Additional 

Series, 13: 389 pages. London: Royal Botanic Gardens. 

Conzatti C. 

1946. Flora Taxonomica Mexicana. Volume 1, 1064 pages. Distrito 

Federal Mexico: Sociedad Mexicana de Historia Natural. 

1885. Manual of Botany of the Rocky Mountain Region. 452 pages. New 

York Ivison, Blakeman, Taylor, and Company. 

1974. A Flexible Program for Generating Identification Keys. Systematic 

Botany, 2350-57. 

1980. A General System for Coding Taxonomic Descriptions. Taron, 

Coulter, J.M. 

Dallwitz, M.J. 

29~4 1-46. 

Davidse, G., and R.W. Pohl 

1992. New Taxa and Nomenclatural Combinations of Mesoamerican 

Grasses (Poaceae). Novon, 2:81-110. 

1964. An Anatomic-Systematic Study of the Classical Tribe Festuceae 

(Gramineae). American Journal ofBotany, 51:453-463. 

1810. Extrait d’un memoire sur quelques nouveau genres de la famille des 

GraminCes. Nouveau Bulletin des Sciences par la Societe Philomatique de Paris, 2:187-190. 

1960. A New Genus of Gramineae. Bothalia, 7:387-390. 

1866. Etude sur la genre Cvpsis et sur ses especies Francaises. Bulletin, 

Societe Botanique de France, 13:3 17-326. 

1994. Alliances of Muhlenbergia (Poaceae) within New World Eragrostideae Are Identified by Phylogenetic Analysis of Mapped Restriction Sites from Plastid DNAs. American Journal of Botany, 

Decker, H.F. 

Desvaux, A.N. 

De Winter, B. 

Duval-Jouve, J. 

Duvall, M.R., P.M. Peterson, and A.H. Christenesen 

81 ~622-629. 

Fournier, E. 

1877. Sur les Arundicacees du Mexique. Bulletin, Societe Botanique de 

France, 24: 177. 

1886. Gramineae. In Mexicanas Plantas. . . . 2: 1-160. Paris. 

Gibbs-Russell, G.E., L. Watson, M. Koekemoer, L. Smook, N.P. Barker, H.M. 

1990. Grasses of Southern Africa. Memoirs of the Botanical Survey of 

South Africa, 58:l-437. 

Gould, F.W. 

1968. Grass Sytematics. 382 pages. New York McGraw-Hill Book Co. 

1975. The Grasses of Texas. 653 pages. College Station, Texas: Texas 

A & M University Press. 

1983. Grass Systematics. 397 pages. College Station, Texas: Texas A&M 

University Press. 

Hackel, E. 

1887. Gramineae. In H.G.A. Engler and K.A.E. Prantl, Die Narurlichen 

Pfanzenfamilien. 11: 1-97. Leipzig. 

1890. The True Grasses. 228 pages. New York Henry Holt and Company. 

[Translated from H.G.A. Engler and K.A.E. Prantl, Die Naturalichen Pfanzenfamilien. by F.L. Scribner and E.A. Southworth.] 

The Genus Cvpsis (Gramineae) in the United States. Systematic 

Botany, 4:267-280. 

Anderson, and M.J. Dallwitz 

Gould, F.W., and R.B. Shaw 

Hammel, B.E., and J.R. Reeder 

1979. 

47 
48 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Harvey, L.H. 

1948. Eragrostis in North and Middle America. 270 pages. Doctoral 

dissertation, University of Michigan, Ann Arbor, Michigan. 

Henry, M.A. 

1979. A Rare Grass on the Eureka Dunes. Fremontia, 7(2):3-6. 

Herrera-Arrieta, Y., and J. Bain 

1991. Flavonoids of the Muhlenbergia montana Complex. Biochemical 

Systematics and Ecology, 19:665-672. 

Correlation between Generated Morphological Character Data and 

Flavonoid Content in the Muhlenbergia montana Complex. Canadian Journal of Botany, 71 :8 16-826. 

Systematics of Gramineae: A Cluster Analysis Study. Taxon, 

Herrera-Arrieta. Y., and W.F. Grant 

1993. 

Hilu, K.W., and K. Wright 

1982. 

3 1 :9-36. 

Hitchcock, A.S. 

1913. Mexican Grasses in the United States National Herbarium. Conh’- 

butions from the United States National Herbarium, 17: 181- 189. 

1920. The Genera of Grasses of the United States. Bulletin, Unitedstates 

Department of Agriculture, 772: 1-307. 

1926. Eragrostis hypnoides and E. reptans. Rhodora, 28:113-115. 

1927. The Grasses of Ecuador, Peru, and Bolivia. Contributionsfrom the 

United States National Herbarium, 24:29 1-556. 

1928. New Species of Grasses from the United States. Proceedings of the 

Biological Society of Washington, 41:157-164. 

1933. New Species and New Names of Grasses from Texas. Journal of the 

Washington Academy of Sciences, 23:449-456. 

1935a. Muhlenbergia (Poales) Poaceae (pars). North American Flora, 

1935b. Manual of the Grasses of the United States. United States 

Department of Agriculture Miscellaneous Publication, 200: 1040 

pages. 

17~431-476. 

Hitchcock, A.S., and A. Chase 

1951. Manual of the Grasses of the United States. United States 

Department of Agriculture Miscellaneous Publication, 200: 105 1 

pages. [Second edition, revised by A. Chase.] 

1934. Gramineae. In J. Hutchinson, The Families of Flowering Plants, 

2: 199-229. London: Macmillan. 

1947. Urochondra setulosa (Trin.) C.E. Hubbard. Hooker’s Icones 

Plantarum, 35(3):1-11, plate 3457. 

1979. A Synoptical Revision of Blepharidachne (Poaceae). Brittonia, 

Hubbard, C.E. 

Hunziker, A.T., and A.M. Anton 

3 1~446-453. 

Judziewicz, E.J. 

1991. Family 187, Poaceae. In A.R.A. GBrtsvan Rijn, editor, Flora of the 

Guianas, Series A: Phanerogams. 127 pages. Konigstein, Germany: 

Koeltz Scientific Publishing. 

Koch, S.D. 

1978. Notes on the Genus Eragrostis (Gramineae) in the Southeastern 

United States. Rhodora, 80:390-403. 

Kunth, K.S. 

1816. Nova Genera et Species Plantarum. In F.H.A. Humboldt and A.J.A. 

Bonpland, Voyage am Regions Equinoxiales du Nouveau Continent, 

fait en 1799-1804, part 6 (Botanique), section 3, 1:141-142, 

plate 45. 

1833. Enumeratio Plantarum. . . . Volume 1, 606 pages. Stutgardia and 

Tubingae. 

Link, G.M. 

1833. Hortus Regius Botanicus Berolinensis, 2: 1-376. Berlin: G. Reimer. 

Lorch, J. 

1962. A Revision of Crypsis Ait. s.1. (Gramineae). Bulletin of the Research 

Council ofIsrael, 1 l(D):91-116. 

Trichoneura Andersson (Gramineae) nuevo genero para la flora 

Matthei, O.R. 

1973. 

Chilena. Boletin de la Sociedad de Biologia de Concepcion, 

46:37-39. 

McNeill, J. 

1979. Diplachne and Leptochloa (Poaceae) in North America. Brittonia, 

3 1 :399-404. 

1983. Flora Novo Galiciana: A Descriptive Account of the Vatcular Plants 

of Western Mexico. Volume 14,436 pages. Ann Arbor: University of 

Michigan Press. 

1960. Anatomy of the Monocotyledons, I: Gramineae. 73 1 pages. Oxford: 

Clmdon Press. 

Mez, C. 

1921. Gramineae novae vel minus cognitae. Repertorium Specierum 

Novarum Regni Vegetabilis, 17:203-214. 

1985. A Biosystematic Study of the Muhlenbergia repens Complex 

(Poaceae). Doctoral dissertation, Texas A& M University, College 

Station, Texas. 

1986. Vegetative Apomixis in Muhlenbergia repens (Poaceae). Sida, 

1987. Anatomical Study of the Muhlenbergia repens Complex (Poaceae: 

Chloridoideae: Eragrostideae). Sida, 12(2):347-359. 

1996. Morphological Variation and Synopsis of the Muhlenbergia repens 

Complex (Poaceae). Sida, 17:349-365. 

Nash, G.V. 

1898. New or Noteworthy American Grasses, VIII. Bulletin of the Torrey 

Botanical Club, 25:83-89. 

1903. Erioneuron. In J.K. Small, Flora of the Southeastern United States, 

143-144. New York Published by the author. 

1829. Calotheca. In C.F.P. von Martius, Flora Brasiliensis, Agrostologia 

Brasiliensis, 2:471. 

Nicora, E.G. 

1962. Revalidacion del genm de Gramineas “Neerapstis” de la flora 

Norteamericana. Revista Argentina de Agronomia, 29: 1- 1 1. 

1987. Los Generos de Gramineas de America Austral. 61 1 pages. Buenos 

Aires: Editorial Hemisfeno Sur S.A. 

1991. Una nueva especie de Tripogon Roemer h Schultes (Poaceati 

Eragrosteae), Tripogon ekmanii E. Nicora & Rugolo. Candollea, 

McVaugh, R. 

Metcalf, C.R. 

Morden, C. W. 

Morden, C.W., and S.L. Hatch 

11~282-285. 

Nees, C.G.D. 

Nicora, E.G., and Z.E. Rugolo de Agrasar 

46:533-535. 

Nuttall, T. 

1848. Descriptions of Plants Collected by Mr. William Gambel in the 

Rocky Mountains and Upper California. Proceedings of the National 

Academy of Sciences in Philadelphia, 4:23. 

Ortiz, J.J. 

1991. Schenckochloa (Poaceae, Chloridoideae, Eragrostideae), un genero 

nuevo del Noreste de Brasil. Candollea, 46:241-249. 

1993. Estudio sistematico del genero Gouinia (Gramineae, Chloridoideae, 

Eragrostideae). Acta Botanica Mexicana, 23: 1-33. 

Parodi, L.R. 

1934. Contribucion a1 estudio de las Gramineas del genero Munroa. 

Revista del Museo del La Plata, 34:171-193. 

1954. Nota preliminar sobre el genero Monanthochloe (Gramineae) en la 

Argentina. Physis, 20(59): 1-3. 

1988. Chromosome Numbers in the Annual Muhlenbergia (Poaceae). 

Madrono, 35:320-324. 

1989. A Re-evaluation of Bealia mexicana (Poaceae: Eragrostideae). 

Madrono, 36:260-265. 

Peterson, P.M., and C.R. Annable 

1990. A Revision of Blepharoneuron (Poaceae: Eragrostideae). Systematic 

Botany, 195 15-525. 

Peterson, P.M. 
NUMBER 87 49 

1991. Systematics of the Annul Species of Muhlenbergia (PoaceaeEragrostideae). Systematic Botany Monographs, 3 1: 1-109. 

1992. A Revision of Chaboissaea (Poaceae: Eragrostideae). Madrono, 

39:8-30. 

Peterson, P.M., C.R. Annable, and V.R. Franceschi 

1989. Comparative Leaf Anatomy of the Annual Muhlenbergia (Poaceae). 

Nordic Journal of Botany, 8575-583. 

Peterson, P.M., and J.T. Columbus 

1997. Allelic Variation in the Amphitropical Disjunct Scleropogon 

brevifolius (Poaceae: Eragrostideae). BioLlania, special edition, 

6:473-490. 

Peterson, P.M., M.R. Duvall, and A.H. Christensen 

1993. Allozyme Differentiation among Bealia mexicana, Muhlenbergia 

argentea, and M. lucida (Poaceae: Eragrostideae). Madroiio, 40: 

148-160. 

Peterson, P.M., and Y. Herrera A. 

1996. Allozyme Variation in the Amphitropical Disjunct, Chaboissaea 

(Poaceae: Eragrostideae). Madrorio, 42:427-449. 

Flavonoids of the Annual Muhlenbergia. Biochemical Systematics 

and Ecologv, 15:647-652. 

1995. Subtribal Classification of the New World Eragrostideae (Poaceae: 

Chloridoideae). Sida, 16529-544. 

Plantarum novarum Chilensium. Linnaea, 29:96-110. 

Peterson, P.M., and L.H. Rieseberg 

1987. 

Peterson, P.M., R.D. Webster, and J. Valdes-Reyna 

Philippi, R.A. 

Phillips, S.M. 

1858. 

1972. A Survey of the Genus Eleusine in Africa. Kew Bulletin, 

1982. A Numerical Analysis of the Eragrostideae (Gramineae). Kew 

Bulletin, 37:133-162. 

A Revision of the African Species of Tripogon. Kew Bulletin, 

27:251-270. 

Phillips, S.M., and E. Launert 

1971. 

Pilger, R. 

1954. Das System der Gramineae unter Auschluss der Bambusoideae. 

Botanisches Jahrbucher fur Systematik, 76:28 1-384. 

1956. Gramineae 11, Unterfamilien: Micraioideae, Eragrostideae, Oryzoideae, Olyroideae. In H. Melchoir and E. Werdermann, editors, Die 

Naturalichen Pflanrenfamilien, second edition, 14: 1-168. 

25:30 1-322. 

Pohl, R.W. 

1969. Muhlenbergia. Subgenus Muhlenbergia (Gramineae) in North 

America. American Midland Naturalist, 82:5 12-542. 

1977. Eragrostis contrerasii, a New Grass Species from Central America 

(Gramineae: Chloridoideae). Iowa State Journal of Research, 

1980. Flora Costaricensis, Family 15, Gramineae. Fieldiana, Botany, 

5 1(3):323-325. 

4: 1-608. 

Presl, J.S. 

1830. 

Rafinesque, C.S. 

18 19. 

In Reliquiae Haenkeanae.. . , 1:207-356. Prague. 

Prodrome: Des nouveaux genres de plantes observes in 18 17 er 18 18 

das l’interieur de Etats-Unis d’America. Journal de Physique, de 

Chimie et d ’Histoire Naturalle, 89: 104. 

Neogenyton, or Indication of Sixty-six New Genera of Plants of 

North America. 4 pages. Lexington, Kentucky. 

Reeder, C.G. 

1985. The Genus Lycurus in North America. Phytologia, 57:283-291. 

Reeder, J.R. 

1957. The Embryo on Grass Sytematics. American Journal of Botany, 

1967. Notes on Mexican Grasses, VI: Miscellaneous Chromosome 

1971. Notes on Mexican Grasses, IX: Miscellaneous Chromosome 

1825. 

44:756-768. 

Numbers. Bulletin of the Torrey Botanical Club, 94: 1-17. 

Numbers-3. Brittonia, 23:105-117. 

1976. Systematic Position of Redfieldia (Gramineae). Madrono, 23: 

434-438. 

Reeder, J.R., and M.A. Ellington 

1960. Calamovilfa, a Misplaced Genus of Gramineae. Brittonia, 12: 

71-77. 

1988. Aneuploidy in the Muhlenbergia subbrjlora Complex (Gramineae). 

Phytologia, 65:155-157. 

Reeder, J.R., and C.G. Reeder 

Reeder, J.R., and L.J. Toolin 

1987. Scleropogon (Gramineae), a Monotypic Genus with Disjunct 

Distribution. Phytologia. 62:267-275. 

Reichenbach, L. 

1828. Conspectus Regnum Vegetabilis per gradus naturales evoluti . . . Pars I. 294 pages. Leipzig. 

Grasses: An Introduction to the Study of Fodder and Cereal 

Grasses. 635 pages. New Delhi: Indian National Science Documentation Center. [Translated from Russian. Published for the Smithsonian Institution and the National Science Foundation, Washington, 

D.C.] 

Ross, R. 

1966. The Generic Names Published by N.M. von Wolf. Acta Botanica 

Neerlandica, 15: 147-161. 

Roshevits, R. Yu 

1980. 

Rydberg, P.A. 

1906. Flora of Colorado. Bulletin of the Colorado State University 

Agricultural Experiment Station, 100: 1-447. 

Sanchez, E. 

1974. Anatomia foliar de las especies Argentinas de 10s generos Eleusine 

Gaertn. y Dactyloctenium Willd., Gramineae, subfamilia Eragrostoideae, tribu Eragrosteae. Darwiniana, 18526-538. 

1983a. Estudios anatomicos en Blepharidachne Hackel (Poaceae, Eragrostideae, Eragrosteae). Revista del Museo Argentino de Ciencias 

Naturales “Bernadino Rivadavia ” e Instituto Nacional de Investigacion de las Ciencias Naturales (Botanicas), 4(3):73-87. 

1983b. Dasyochloa Willdenow ex Rydberg (Poaceae), Genero monotypico 

de North America. Lilloa, 36:131-138. 

Estudio taxonomico sobre el genero Lycurus (Gramineae). Parodiana, 4:267-3 10. 

1789. In C. Linnaeus, Genera Plantarum . . . , eighth edition, 1:44-45. 

Frankfurt A.M.: Vamntrapp and Wenner. 

1899. New Species of North American Grasses. United States Department 

of Agriculture, Division of Agrostologv, 16: 1-6. 

1984. Inventory of Rare and Endangered Vascular Plants of California. 

Third edition, 178 pages. California Native Plant Society, Special 

Publication No. I. 

Sanchez, E., and Z.E. Rug010 de Agrasar 

1986. 

Schreber, J.C.D. 

Scribner, F.L. 

Smith, J.P., Jr., and R. York 

Soderstrom, T.R. 

1967. Taxonomic Study of the Subgenus Podosemum and Section 

Epicampes of Muhlenbergia (Gramineae). Contributions from the 

United States National Herbarium, 34(4):75- 189. 

1963. Swallenia, a New Name for the California Genus Ectospenna 

(Gramineae). Madrono, 17:88. 

1964. Reederochloa, A New Genus of Dioecious Grasses from Mexico. 

Brittonia, 16:334-339. 

1965. Allolepis: A New Segregate of Distichlis (Gramineae). Madrono, 

Sohns, E.R. 

1953. Chaboissaea ligulata Foum.: A Mexican Grass. Journal of the 

Washington Academy of Sciences, 43:405-407. 

1956. Calamochloa: A Mexican Grass. Journal of the Washington 

Academy of Sciences, 46: 109- 1 12. 

Soderstrom, T.R., and H.F. Decker 

18:33-39. 
50 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Stapf, 0. 

1898. Gramineae. In W.T. Thiselton-Dyer, editor, Flora Capensis, 7(2-4): 

310-791. London. 

1961. A Suggested Revision of the Grass Genera of Temperate North 

America. Recent Advances in Botany, 1: 133-145. 

Steudel, E.T. 

1840. Nomenclator Botanicus, I: Typis et Sumptibus. 852 pages. Stuttgartia et Tubingae: J.G. Cottae. 

Sutton, D.D. 

Leaf Anatomy on the Subfamily Eragrostoideae. Michigan Academician, 5:373-383. 

The Grass Genus Gouinia. American Journal oflotany, 22:31-41. 

The Awnless Annual Species of Muhlenbergia. Contributions from 

the United States National Herbarium, 29:203-208. 

Ectosperma, a New Genus of Grasses from California. Journal of the 

Washington Academy of Sciences, 40: 19-21. 

A Biosystematic Study of Tridens (Gramineae). American Journal 

of Botany, 48: 565-573. 

Synopsis of the Genus Calamovilfa (Gramineae). Castanen, 3 1: 

Stebbins, G.L., and B. Crampton 

1973. 

Swallen, J.R. 

1935. 

1947. 

1950. 

Tateoka, T. 

1961. 

Thieret, J.W. 

1966. 

Thurber, G. 

1863. 

145- 152. 

Graphephorum. In Enumeration of the Species of Plants Collected 

by Dr. C.C. Parry, and Messrs. Elihu Hall and J.P. Harbour, during 

the Summer and Autumn of 1862, on and Near the Rocky 

Mountains, in Colorado Territory, lat. 39"-41", by Asa Gray. 

Proceedings of the Academy of Natural Sciences of Philadelphia, 

1863:78. 

The General Botanical Collections. In Reports of Explorations and 

Surveys, to Ascertain the Most Practicable.. . Route for a Railroad 

from the Mississippi River to the Pacific Ocean (Report on the 

Botany), 4(5):1-167. 

Species graminum. Memoires de 1 'Acadernie Imperiale des Sciences 

de St. Petersburg, series 6, 1 :363. 

Contribucion a1 conocimiento de las especies Argentinas de genero 

Gouinia Foumier. Lilloa, 34:57-88. 

Torrey, J. 

1857. 

Trinius, K.B. 

183 I. 

Turpe, A.M. 

1975. 

Tzvelev, N.N. 

1968. Sistema zlakov (Poaceae) flory SSSR. Botanicheski? Zhurnal, 

53:311. 

A Biosystematic Study of the Genus Erioneuron Nash (Poaceae: 

Eragrostideae). Doctoral dissertation, Texas A & M University, 

College Station, Texas. 

Valdes-Reyna, J., and S.L. Hatch 

Lemma Micromorphology in the Eragrostideae (Poaceae). Sida, 

Valdes-Reyna, J. 

1985. 

1991. 

141531-549. 

Van den Borre, A,, and L. Watson 

1994. The Infrageneric Classification of Eragrostis (Poaceae). Taxon, 

Vasey, G. 

43~383-422. 

1887a. New Species of Mexican Grasses. Bulletin of the Torrey Botanical 

1887b. Redfieldia, a New Genus of Grasses. Bulletin of the Torrey Botanical 

1890. In J.M. Coulter, Upon a Collection of Plants Made by Mr. G.C. 

Nealley, in the Region of the Rio Grande, in Texas, from Brazos 

Santiago to El Paso County. Contributions to the United States 

National Herbarium, 1 :29-65. 

1891. A New Grass: Melica multinervosa. The Botanical Gazette, 

1899. Gramineae. In T.S. Brandegee, A Collection of Plants from Baja 

California. Proceeding9 of the California Academy of Science, 

Club, 14:8-10. 

Club, 14:133-134. 

235-236. 

2:210-214. 

Villamil, C.B. 

1969. El genero Monanthochloe (Gramineae), estudios morfologicos y 

taxonomicos con especial referencica a la especie Argentina. 

Kurtziana, 5:369-391. 

Watson, L., H.T. Clifford, and M.J. Dallwitz 

The Classification of Poaceae: Subfamilies and Supertribes. Australian Journal of Botany, 33:433-484. 

The Grass Genera ofthe World. 1038 pages. Wallingford, United 

Kingdom: C.A.B. International. 

Botany. In C. King, Geological Exploration of the 40th Parallel, 5: 

525 pages. Washington, D.C.: Government Printing Office. 

1988. Genera of the North American Paniceae (Poaceae: Panicoideae). 

Systematic Botany, 13(4):576-609. 

1992a. Old World Genera of the Paniceae (Poaceae: Panicoideae). Sida, 

1992b. Character Significance and Generic Similarities in the Paniceae 

1985. 

Watson, L., and M.J. Dallwitz 

1992. 

Watson, S. 

187 I. 

Webster, R.D. 

l5( l):9-40. 

(Poaceae: Panicoideae). Sida, 15(2): 185-2 13. 

New World Genera of the Paniceae (Poaceae: Panicoideae). Sida, 

Webster, R.D., J.H. Kirkbride, and J. Valdes-Reyna 

1989. 

13(4):393-4 17. 

Webster, R.D., and J. Valdes-Reyna 

1988. Genera of the Mesoamerican Paniceae (Poaceae: Panicoideae). Sida, 

13(2): 187-221. 

de Winter, B. 

1966. 

Wolf, N.M. von 

1776. 

Yates, H.O. 

1966a. Morphology and Cytology of Uniola (Gramineae). The Southwestern Naturalist, 1 1: 145- 189. 

1966b. Revision of the Grasses Traditionally Refered to Uniola, I: Uniola 

and Leptochloopsis. The Southwestern Naturalist, 1 1 :372-393. 

1967. Revision of Grasses Traditionally Referred to Uniola, 11: Chasmanthium. The Southwestern Naturalist, 11 :415-455. 

Styppeiochloa de Winter, gen. nov. Bothalia, 9: 134-137. 

Genera Plantarum Vocabulis Characteristicis Dejnita. 177 pages. 

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