SMITHSONIAN CONTRIBUTIONS TO BOTANY 0 NUMBER 65 

The Phareae and Streptogyneae 

(Poaceae) of Sri Lanka: 

A Morphological-Anatomical Study 

Thomas R. Soderstrom, Roger P. Ellis 

and Emmet J. Judziewicz 

SMITHSONIAN INSTITUTION PRESS 

Washington, D.C. 

1987 
ABSTRACT 

Soderstrom, Thomas R., Roger P. Ellis, and Emmet J. Judziewicz. The Phareae 

and Streptogyneae (Poaceae) of Sri Lanka: A Morphological-Anatomical Study. 

Smithsonian Contributions to Botany, Number 65, 27 pages, 8 figures, 1987.-A 

morphological-anatomical study of the herbaceous bamboos (Poaceae: Bambusoideae) 

of Sri Lanka is presented. The occurrence of Scrotochloa urceolata and Leptaspis 

zeylanica of the Phareae and Streptogyna crinita of the Streptogyneae on the island 

represents the easternmost region in which these tribes of animal-dispersed, rain 

forest grasses are found together, a fact of phytogeographic significance, since both 

groups are the only herbaceous bamboo tribes found in both the Old World and the 

New World. Morphologically, Leptaspis and Scrotochloa possess strongly pseudopetiolate, inverted, oblique1 -veined, usually broad leaves with an inner ligule and 

flowered spikelets; the mature female florets are in ated and covered with uncinate 

macrohairs that facilitate epizoochory, and the male spikelets have six stamens. 

Streptogyna has narrower, non-inverted, parallel-veined leaves that possess inner and 

outer ligules. The perfect, several-flowered spikelets have two or three stigmas and 

two stamens and are borne in a spikelike raceme; at maturity the florets may detach 

and adhere to animals by means of a complex of awns, retrorsely barbed stigmas, 

and rachilla internodes. Details of leaf anatomy indicate that both tribes are peripheral 

members of the Bambusoideae. 

Transverse sections of the blades reveal typically bambusoid features such as a 

complex midrib vasculature, prominent fusoid cells, at least rudimentary arm cells, a 

multi-layered inner vascular bundle sheath composed of small, thick-walled cells, and 

an outer bundle sheath of large, colorless cells. The epidermides of the Phareae and 

Streptogyneae are quite distinct from each other and from typical bamboos. The 

pharoid grasses, unlike bamboos, possess intercostal fibrous bands, dumbbell-shaped, 

horizontal silica bodies, and poorly developed bulliform cells. Streptogyna, while less 

anomalous, also possesses somewhat fiber-like intercostal cells. Bicellular microhairs 

and well-developed, minute epidermal papillae, both typically bambusoid features, 

are absent from the leaf-blades of both tribes. 

ff transverse veinlets. The in K orescence is an open anicle bearing unisexual, oneOFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the 

Institution’s annual report, Smithsonian Year. SERIES COVER DESIGN: Leaf clearing from the katsura tree 

Cercidiphyllum japonicum Siebold & Zuccarini. 

Library of Congress Cataloging in Publication Data 

Soderstrom, Thomas R. 

The Phareae and Streptogyneae (Poaceae) of Sri Lanka. 

(Smithsonian contributions to botany ; no. 65 

Bibliography: p. 

Includes index. 

Supt. of Docs. no. : SI 1.29 :65 

1. Grasses-Sri Lanka. 2. Grasses-Morphology. 3. Grasses-Anatomy. 4. Botany-Sri Lanka. 5. 

Botany-Morphology. 6. Botany-Anatomy. I. Ellis, Roger P. 11. Judziewicz, Emmet J. 111. Title. 

IV. Title: Streptogyneae (Poaceae) of Sri Lanka. 

QK1 .S2747 no. 65 581 s 86-600284 [QK495.G74] [584’.909549’3] 

V. Series. 
Contents 

Page 

Preface ...................................................... iv 

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

TribePHAREAE ............................................... 2 

Genus Scrotochloa ............................................ 3 

3 

Scrotochloa urceolata ......................................... 3 

Key to the Genera of the Phareae ............................... 3 

Key to the Species of Scrotochloa ............................... 

Morphology .............................................. 4 

Anatomy ................................................. 7 

Genus Leptaspis .............................................. 9 

Key to the Species of Leptaspis ................................ 10 

Leptaspis zeylanica .......................................... 10 

Morphology .............................................. 10 

Anatomy ................................................. 12 

T~~~~STREPTOGYNEAE .......................................... 12 

Genus Streptogyna ............................................ 13 

Key to the Species of Streptogyna ............................... 13 

Streptogyna crinita .......................................... 13 

Morphology ............................................... 13 

Anatomy ................................................. 15 

Phylogenetic Considerations ..................................... 17 

17 

18 

21 

ListofTaxa .................................................. 25 

Literature Cited ............................................... 26 

Morphological and Anatomical Diagnosis of the Bambusoideae ....... Relationships of the Phareae to the Bambusoideae ................. Relationships of the Streptogyneae to the Bambusoideae ............ 

... 

111 
Preface 

The impetus for this paper came through an invitation from Dr. F. Raymond 

Fosberg to prepare an extensive treatment of the grasses of Ceylon to be included 

in “A Revised Handbook to the Flora of Ceylon.” I gladly consented to do so, 

especially in view of the fact that Fosberg’s Flora of Ceylon Project, headquartered 

at the Smithsonian Institution, would provide me with round-trip air transportation 

to that far-away island and cover all expenses of a three-month stay collecting grasses. 

It occurred to me that it would be ideal if I could enlist the cooperation of other 

agrostologists, each visiting the island for a different three-month period to make 

general collections and be responsible for writing the treatments of a particular set 

of genera, especially in his field of expertise. This plan worked out admirably, and 

three leading agrostologists seized upon this opportunity. Dr. W. Derek Clayton of 

Kew travelled to Ceylon from January through March 1970, overlapping somewhat 

the period of March through May when Dr. Frank W. Gould of Texas A & M 

University and his wife, Lucile, visited the island. From July through September Dr. 

Michael Lazarides of C.S.I.R.O. in Australia collected in Ceylon. Dr. Norman Bor, 

who had published widely on the grasses of Southern Asia (1960) had kindly 

consented to identify the first set of specimens from Ceylon as they were assembled 

at Kew. 

My own trip to Ceylon had been made the year before, from October through 

December, when I went to make collections of the bamboos. Mrs. Gesina Berendina 

Threlkeld, who had made many illustrations for me previously, accompanied me to 

Ceylon to work with fresh material. When flowering material was not available, 

dissections of herbarium specimens were made later in Washington and illustrations 

of these rendered by Alice R. Tangerini. The world’s expert on bamboos and my 

mentor at the Smithsonian was Dr. F.A. McClure, who had agreed to prepare the 

bamboo treatment and also to go to Ceylon to collect. But shortly after our 

preliminary discussions in early 1969 he told me that he did not feel that his state of 

health would permit an arduous trip to Ceylon and he would not be able to go; 

furthermore he asked that I do the treatment with the assurance that he would help 

me along the way. Shortly after my return from Ceylon, my dear friend and mentor 

passed away on April 15, 1970. 

The unexpected death of Dr. Bor on December 22, 1972, was a great loss to the 

field of agrostology and to our project in particular. I was fortunate to find another 

collaborator, Dr. Gerrit Davidse of the Missouri Botanical Garden, to write up the 

genera for which Bor was responsible. Our newest collaborator travelled to Ceylon 

in 1974, where he made a large and impressive collection of grasses and other plants 

during his stay there from October to mid-December. 

My own assignment, the Bambusoideae, proved difficult from the beginning, as 

my previous studies had been confined to herbaceous bambusoid grasses, with little 

attention paid to the bamboos themselves during the time McClure was active. After 

McClure’s death, I was thrust into the study of bamboos by editing his manuscript 

entitled, “Genera of Bamboos Native to the New World (Gramineae: Bambusoideae),” which appeared in 1973. Almost a whole year was devoted to this task and 

that of sorting out his office, in which I had the wonderful assistance of his wife, 

Ruth Drury McClure. 

The state of taxonomy of the woody bamboos in general, not just those of Sri 

iv 
NUMBER 65 V 

Lanka, provided the impetus to undertake a broad survey of the leaf anatomy of the 

Bambusoideae; toward this end I began a collaborative effort in 1980 with Dr. Roger 

P. Ellis of the Botanical Research Institute in Pretoria, South Africa. This survey was 

a necessary step in understanding better the generic limits of the bamboos and in 

interpreting the genera of Sri Lanka. The results of this anatomical study are now 

being written up, as is the study of the Ceylonese bamboos themselves; and the 

Grasses of Ceylon volume is now being edited. 

The present paper, which is a small portion of the entire study, covers only the 

herbaceous bamboos of Sri Lanka. When we wrote the first draft of this paper there 

were two described genera: Streptogyna and Leptaspis. During the past two years, a 

graduate student at the University of Wisconsin (Madison), Emmet J. Judziewicz, has 

made a study of the genus Pharus, which is confined to the New World. He is now 

continuing his investigations on its Old World sister genus, Leptaspis and a further 

genus, which he segregated from it and called Scrotochloa. Judziewicz is presently at 

the Smithsonian Institution as a pre-doctoral fellow (September 1985-August 1986) 

to carry out research on several herbaceous tribes of Bambusoideae, including the 

Anomochloeae, Phareae, Streptochaeteae, and Streptogyneae. Because of the expertise that he has acquired in the Phareae and his present studies on the Streptogyneae, 

we have asked him to contribute to this paper. 

This publication is thus the result of a long series of events and, we hope, will be 

a worthy contribution to our understanding of these unusual herbaceous bamboos. 

We have attempted to present details of the morphology, along with those of leaf 

anatomy, of the two herbaceous tribes represented in Sri Lanka. More interesting, 

perhaps, than such details of the plants’ structure is the distribution of the genera 

and their Singhalese connection. As the reader will learn, we have not denied 

ourselves the opportunity to speculate on this intriguing question. 

T.R. Soderstrom 

19 September 1985 

The Phareae and Streptogyneae 

(Poaceae) of Sri Lanka: 

A Morphological-Anatomical Study 

Thomas R. Soderstrom, Roger P. Ellis 

and Emmet J. Judziewicx 

Introduction 

In the shaded understories of the world’s tropical forests 

occur seven or eight tribes and perhaps 150 species of 

herbaceous, broad-leaved grasses that, based on details of 

leaf anatomy and spikelet structure, are now generally 

considered to be allied to the woody Bambusoideae (Calder6n and Soderstrom, 1980). Three tribes of these herbaceous bamboos, the Streptochaeteae, Streptogyneae, and 

Phareae, have mature spikelets that are variously adapted 

for dispersal via the fur and feathers of animals. These 

epizoochorous adaptations may be an important reason why 

these probably ancient, relictual grasses have been able to 

survive to the present day (Soderstrom, 198 l), while distant 

cousins that lacked such adaptations have become extinct 

or nearly so. For example, Anomochloa marantoidea of the 

monotypic tribe Anomochloeae is now known only from a 

single forest in Brazil. 

Sri Lanka marks the easternmost outpost in which two of 

these epizoochorous tribes co-occur. Scrotochloa urceolata 

and Leptaspis zeylanica (both Phareae) and Streptogyna crinita 

(Streptogyneae) are present on the island, and it is noteworthy that these groups are the only tribes of herbaceous 

bamboos that are native to both hemispheres. The Phareae 

are found in the tropical regions of Latin America, Africa, 

Southeast Asia, Australia, and Oceania; the Streptogyneae 

grow in tropical Latin America, Africa, southern India, and 

Sri Lanka. The occurrence of these grasses on Ceylon poses 

a question of great phytogeographical interest, and two 

explanations may be advanced for their pantropical distributions. 

Thomas R. Soderstrom, Department of Botany, National Museum of Natural 

History, Smithsonian Institution, Washington, D.C., 20560. Roger P. Ellis, 

Botanical Research Institute, Private Bag XlOl, Pretoria, South Africa. Emmet 

J. Judziewicz, Department of Botany, University of Wisconsin, Madison, Wisconsin, 53706. 

Based on their resemblance to the woody bamboos, both 

the Phareae and the Streptogyneae are probably quite ancient taxa, and so it is tempting to explain their amphiAtlantic ranges on the basis of continental drift. In this 

scenario, the proto-pharoid and proto-streptogynoid stocks 

were present throughout the Gondwanaland super-continent, and upon the separation of South America from 

Africa during the Cretaceous (Raven and Axelrod, 19’74) 

new climatic and biological parameters, aided by genetic 

isolation, allowed natural selection to proceed in different 

directions on both sides of the newly-formed Atlantic 

Ocean. Phylogenetic differentiation proceeded to the genus 

level in the Phareae and to the species level in the Streptogyneae. At the beginning of the Paleocene, South America 

and Africa were separated by about 800 km, or about ’h of 

their present distance, while to the east the Indian subcontinent, including Sri Lanka, had completed its separation 

from Madagascar. In succeeding eras the original AfroIndian plants could then have been rafted northeastward; 

they probably migrated to Asia when that plate collided 

with the Indian plate in about the Middle Eocene. During 

this rafting period it is believed that India and Sri Lanka 

retained a warm, wet climate (R.O. Whyte, pers. comm.), 

and upon “impact” with Asia the pharoids could have spread 

eastward to Southeast Asia before the late Tertiary cooling 

and drying trend in world climate reduced their ranges to 

their present isolated sites at the southern tip of the Indian 

subcontinent. The streptogynoids either did not reach 

Southeast Asia or have since become extinct in the region. 

One difficulty with this hypothesis is that there is no evidence that the Poaceae were in existence during the Mesozoic; the earliest fossil grass pollen known is from the 

Paleocene and occurred in South America, Africa, and 

Australia (Muller, 198 1). 

A second explanation for the present distribution of the 

pharoid and streptogynoid grasses might invoke relatively 

1 
2 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

recent (late Tertiary), long-distance dispersal by migrating 

or stray birds (Carlquist, 1974) as the means by which these 

taxa attained their present wide ranges. This process might 

have been facilitated by the manifestly epizoochorous nature of the disseminules in both tribes. The pharoid female 

floret is a compact, uncinate-covered structure, generally 

less than 1 cm long, that detaches singly from the branches 

of the inflorescence. That the Phareae can certainly travel 

is evidenced by their presence on many isolated islands. 

Pharus lappulaceus grows on many of the Lesser Antilles 

and also on the tiny Swan Islands north of Honduras. 

Leptaspis angustqolia, a clearly specialized taxon, has 

n the Pacific Ocean, and L. zeylanica grows on 

islands in three oceans: Sao Tome in the Atlantic, the 

Comoro Islands, Madagascar, and Sri Lanka in the Indian 

Ocean, and New Britain, New Ireland, and Bougainville in 

the Pacific. The spikelets of Streptogyna are larger (2-3 cm 

long) and usually disarticulate as a group via a complex of 

awns and coiling stigmas, making the possibility less likely 

that a bird would complete a trans-oceanic journey with 

such a mass of large, foreign objects adhering to its feathers. 

The relatively awkward nature of this type of epizoochory 

may be reflected in the more continental distribution of the 

genus: the only islands from which Streptogyna is recorded 

are Trinidad and San Jose Island (Panama) in the New 

M’orld and Fernando Po (Hubbard, 1956) and Sri Lanka in 

the Old World, all of which are less than 100 km from a 

continent . 

The more likely method of dispersal of these grasses is 

continental drift, probably followed by over-water dispersal 

by birds when the American and African land masses were 

only a few hundred kilometers apart or bridged by island 

chains during the early Tertiary. The possibility remains 

that Leptaspis, Scrotochloa, and especially Streptogyna have 

continuously resided on Sri Lanka for tens of millions of 

years. To understand the full phytogeographic significance 

of the distribution of these extraordinary Singhalese grasses 

will require elucidation of the intra- and inter-tribal taxonomic relationships of all the tribes of herbaceous bamboos, 

based on careful anatomical and morphological studies. 

This study is a contribution toward that goal. 

the leaf-blade in cross-section, dried (herbarium) material 

was hydrated by boiling or treatment with Contrad 70. 

Both dried and field-preserved (in a formalin-acetic acid 

solution) material was then treated with hydrofluoric acid 

to remove silica, dehydrated Lvith 2-2-dimethoxypropane, 

embedded in paraffin, and sectioned on a rotary microtome 

at 10 or I 3 pni. Staining was effected by either the safraninfast green series or by chlorozol black E, and photographs 

were taken through a Leitz Ortholux compound microscope. Epidermal peels were prepared following the method 

of Tomlinson (1 96 l), then stained in safranin 0 or chlarozol 

black E and mounted in clear resin under weighted cover 

XIATERIALS AND METHODS-For anatomical studies Of 

slips. Pressed specimens were examined from the National 

Herbarium of Sri Lanka in Peradeniya (PDA), from the 

United States Yational Herbarium (US), and, for specimens 

of the pharoid genera from B, BR, GH, L, LE, NY, and P. 

ACKNOWLEDGMENTS.-The first author is grateful to Dr. 

F. Raymond Fosberg for the opportunity afforded him to 

carry out fieldwork in Sri Lanka as a participant in the 

Flora of Ceylon project; and to the Smithsonian Research 

Opportunity Fund that made it possible to travel to South 

Africa in 1983 to ivork in the laboratory of Dr. Ellis. We 

thank Stanley Yankowski of the Smithsonian for preparing 

many of the leaf anatomical slides used in this study; and 

Alice R. Tangerini (ART) of the same institution for the 

several fine and detailed line drawings that she prepared 

for this paper. Thanks are also due to Mrs. Gesina Berendina Threlkeld (GBT), who prepared illustrations in Ceylon 

for all the bambusoid species. 

Tribe PHAREAE 

PHAREAE Stapf, 1898:319 

TYPE GENus.-Pharus P. Browne. 

DIAGsosrs.-Herbaceous grasses of shaded forest understories. Leaves with a prominent pseudopetiole twisted 

180 O at the summit, thus bringing the morphologically 

abaxial surface into an upward-facing, functionally adaxial 

position; outer ligule absent; inner ligule small, membranous; blades with the lateral nerves diverging obliquely from 

the midnerve. Znjorescence: an open, terminal panicle, the 

rachis and branches covered with minute, uncinate hairs. 

Spikelets: unisexual, 1 -flowered, mostly paired, the female 

spikelets large, subsessile to short-pedicelled, the male spikelet small, short- to long-pedicelled. Female spikelets: glumes 

2, usually purple, shorter than the floret; lemmas indurate, 

covered wholly or in part by uncinate macrohairs; palea 2- 

nerved; lodicules apparently absent; ovary with a single style 

and 3 stigmas; fruit a caryopsis, the narrow hilum extending 

its entire length, the embryo small, basal. Male spikelets: 

membranous; glumes 2, shorter than the floret; lodicules 

0-3; stamens 6; basic chromosome number n = 12 (Hunziker, Wulff, and Soderstrom, 1982). 

The Phareae are an anomalous tribe of three well-defined 

genera and about a dozen species of tropical forest grasses. 

The genera are differentiated principally by the morphology of the mature female florets, which are covered with 

hooked hairs as an adaptation for external animal dispersal, 

and by the mode of disarticulation (if any) of the branches 

of the panicle. Two genera, Leptaspis and Scrotochloa, occur 

in Sri Lanka. Leptaspis may be the most primitive genus in 

the tribe, based on its persistent, non-disarticulating panicle 

branches and the presence of glume-like bracts subtending 

the 1st female glunie and also the branchlet on which the 

female/niale spikelet pair is borne. Scrotochloa is clearly 

advanced in its umbelliform panicles that detach from the 
NUMBER 65 3 

summit of the peduncle. A third genus, Pharus, occurs in 

the New World and appears to be intermediate in terms of 

specialization. 

DISTRIBUTION.-Three genera in the tropics of both 

hemispheres. 

Key to the Genera of the Phareae 

1. Mature female floret cylindrical, with strongly inrolled, usually free margins; axis 

of inflorescence prolonged into a naked or few-flowered bristle; male floret 

persistent; New World (7 species, Florida, Mexico to Argentina, Uruguay) .... 

........................................................ Pharus 

Mature female floret globose, inflated, with fused margins; axis of inflorescence 

not prolonged into a bristle; male floret deciduous; Old World .......... 2 

2. Mature female lemma urceolate, 13-nerved (at least at summit). the pore 

through which the style exits appearing terminal; some female spikelets 

solitary; main branches of inflorescence in verticils of 4-8, these and the 

associated node disarticulating as a unit from the summit of the peduncle at 

maturity; principal nodes of inflorescence 1 (rarely 2); female and male 

glumes blunt, caducous (2 species, Sri Lanka, India to Australia, Solomon 

Islands). .......................................... Scrotochloa 

Mature female lemma cochleate, strongly 7-nerved, the pore through which 

the style exits appearing lateral; female and male spikelets all paired; main 

branches of inflorescence borne singly, in pairs, or in verticils of 3, not 

disarticulating from the rachis at maturity; nodes of inflorescence 3-8; female 

and male glumes cuspidate, persistent (3 species, Guinea, Angola to Taiwan, 

Australia, Fiji) ....................................... Leptaspis 

1. 

2. 

Genus Scrotochloa 

Scrotochloa Judiiewicz, 1984:299. 

TYPE SPECIES.-Scrotochloa urceolata (Roxburgh) Judziewicz. 

DIAGNOSIS.-P~ants with hollow culms (or apparently 

solid in S. tararaensis), erect or with age becoming decumbent and rooting at the nodes. Leaves: sheaths somewhat 

compressed; blades narrow to broad. InJlorescence: longpedunculate, unibelliform, with one principal node and 4- 

8 primary branches, the entire structure at maturity disarticulating at the summit of the peduncle, the rachis not 

prolonged into a bristle. Spikelets: paired or the female 

solitar) ; female spikelet short-pedicelled, the male spikelet 

long-pedicelled. Female spikelets: borne on slightly clavate 

pedicels; glunies caducous, blunt to acute, 5-7-nerved; lemnias urceolate, lvith connate margins and a terminal pore 

through which the style exits, indurate and densely covered 

with uncinate macrohairs at maturity; stigmas subplumose. 

Male spikelets: caducous; lemmas more or less tubular but 

with free margins; lodicules apparently lacking; basic chromosome number unknown. 

DISTRIBUTION.-sri Lanka and southern India to Vietnam, Indonesia, New Guinea, Australia, and the Solomon 

Islands. 

SPECIES OF Scrotochloa IN SRI LANKA.- Scrotochloa urceolata. 

Key to the Species of Scrotochloa 

Leaf blades oblong, 4-8 cm wide, glabrous; female spikelets 4-6 mm long; range of 

the genus ............................................. S. urceolata 

Leaf blades linear, about 1 cm wide, usually puberulent beneath (adaxially); female 

spikelets 3-4 mm long; rare, Papua, New Guinea and Australia ... S. tararaensis 

Scrotochloa urceolata Leptaspis urceolata (Roxburgh) R. Brown in Bennett, 1838:23, pl. 6; 

Thwaites 1864:357; Hooker f., 1900:190-191; Senaratna, 1956:21- 

22; Bor, 1960:617,619. 

Leplaspis manillensis Steudel, [ 1855]:8. [Type: Philippines, Leyte, Cumzng 

1739. Holotype, P!, isotypes BM!, L!, LE!, P!.] 

Scrotochloa urceolata (Roxburgh) Judziewicz, 1984:299. 

Pharus urceolatus Roxburgh, 183261 1-6 12. [Type: Malaysia, Pulo Pinang, 

u?ithout collector, Herbarium Roxburgh. Holotype, BM!] 
4 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

MORPHOLOGY 

FIGURES 1, 2 

DESCRIPTION.-Phnts: with shallow rhizomes, the 

strongly ribbed internodes 1-4 cm long, the sheathed nodes 

each bearing 1 or 2 thick, hard, long primary (prop) roots, 

these 1-2 mm in diameter, naked for several cm before 

bearing secondary roots; rhizome continuous into the aerial 

axis (culm) of the plant, further culms often produced singly 

from the 2 or 3 rhizome nodes proximal to the main culm, 

resulting in formation of a clump of few individuals. Culms: 

to about 50 cni tall, covered by a thick, keeled layer of 

overlapping sheaths, the lowermost without blades, the 

succeeding ones with gradually larger blades. Leaves: 

sheaths elongate, glabrous, strongly ribbed, narrowed into 

a pseudopetiole about '/i the length of the blade, manifestly 

tessellate on the inner (adaxial) surface, glabrous except at 

the narrowed and irregular transition zone between sheath 

and pseudopetiole where shortly appressed-pubescent; ribs 

of the sheath continuous with those of the outer (abaxial) 

side of the pseudopetiole and lower (morphologically adaxial) face of the blade; blades broadly obovate, 15-25 cm 

long, 4-6 cm wide, flexuous, tapering at the base, acuminate 

at the apex; upper (abaxial) surface glabrous, darker green 

than the lower, the midvein prominent, elevated, green, the 

primary veins emanating from it along the lower half; lower 

(adaxial) surface glabrous, pale green, strongly tessellate, 

the broad midvein level or slightly depressed, stramineous, 

smooth, shiny; ligule about 0.5 mm long, glabrous on the 

inner (adaxial) surface, densely ciliate on the outer surface. 

Injlorescence: terminal on an exserted peduncle; rachis about 

12 cni long, strongly angled and densely covered by short 

uncinate hairs, bearing whorls of branches at the single 

principal node; primary branches of principal node about 6 

to 14 cni long, at first ascending, at maturity stiffly spreading or some reflexed, densely covered with short uncinate 

hairs; upper nodes of inflorescence greatly reduced, the 

second node bearing about 3 short primary branches, successive nodes indistinct. Inflorescence at maturity falling 

entire, disarticulating just below the principal node, the 

whorled branches persistent or occasionally disarticulating 

from the rachis. Primary inflorescence branches bearing 

short, thin secondary branches, these terminating in a male 

spikelet; belou this a pedicelled female spikelet. Female 

spzkelets: 4-6 mm long, when young obovate and symmetrical, purplish-brown; glumes caducous, slightly coriaceous, 

greatly wrinkled; 1st glume shorter than the 2nd, about 4/i 

its length, more or less obovate, indistinctly 7-9-nerved, 

glabrous; 2nd glume the length of the spikelet at anthesis, 

broadly obovate and with inflexed margins, 2-keeled, concave between the keels, indistinctly 7-nerved, with some 

transverse veinlets, glabrous; lemmas at anthesis shorter 

than the 2nd glume, more or less fusiform, narrowed above 

into a short neck with an opening through which the stigmas 

and tip of the palea emerge, densely covered with delicate 

uncinate hairs, obscurely nerved; lemmas at maturity expanding into a hardened, inflated, urceolate structure with 

a narrowed, stipe-like base and a coarse abaxial groove, 

densely covered with stout uncinate macrohairs except at 

the flattened, slightly beaked summit, evidently 13-nerved 

only at the summit; palea longer than the lemma, tonguelike, 2-keeled, the sides parallel, glabrous below, the emergent tip densely covered on both surfaces by uncinate hairs. 

Gynecium: ovary gradually narrowed into an elongate style, 

dividing above into 3 subplumose stigmas; vestigial andrecium present as 6 minute staminodes situated asymmetrically around the base of the ovary; caryopsis not welldeveloped in the material examined but apparently about 

'LJ the length, of the lemma, in front view more or less 

obtriangular, in lateral view strongly arched on the hilum 

(palea) side, deeply grooved, the broad hilum lying in the 

center of the groove; embryo about Ih the length of the 

fruit. Male spikelets: overtopping the female and terminating 

the entire inflorescence, 3-4 mm long, ovoid, stramineous; 

1st glume about 'h the length of the spikelet, triangular 

with a broad apex, glabrous, nerveless; 2nd glume twice as 

long as the first, broadly obovate with an irregular dentate 

margin, 3-nerved; lemma more or less tubular and completely enclosing the andrecium, narrowing at the summit, 

covered by tiny appressed uncinate hairs, 7-nerved with 

some transverse veinlets; palea slightly shorter than the 

lemma, narrow with parallel sides and bifid at the apex; 

lodicules lacking. Andrecium: anthers orange-yellow, about 

3 mm long, basifixed, the filament attached to the connective at the lower 'h of the anther; vestigial gynecium present 

as a tiny, rudimentary, 3-pronged structure in the center of 

the andrecium. 

SPECIMENS EXAMINED.-KANDY DISTRICT: Peradeniya 

Botanical Garden [cultivated?], without collector, anno 1903 

(NSW). KURUNEGALA DISTRICT: Kurunegala [as Kurunagalle], Aug 1847, Gardner s.n., C.P. 972 (PDA); Dolukanda, 

Soderstrom 2562 (US); [as Doluwa Kande], Dec 1883, Trimen 

s.n. (PDA); Hinadure [as Himidoor], May 18[5]5, without 

collector, C.P. 972 (PDA). KEGALLA DISTRICT: Ca. 40 miles 

SE of Kandy, across river from Kitugala, Could and N. 

Balakrishnan 13874 (PDA, US); Kelaniya River, near Kitulgalle, Kostermans 28395 (AAU). RATNAPURA DISTRICT: Sri 

Palabaddala, Waas 419 (NY, PDA, US); Gilimale, N. Balakrishnan 620 (PDA, US); Horagalkanda, Sinharaja, Waas 

FIGURE I.-Scrotochloa urceolata: a, habit of basal part of plant, showing 

decumbent culm with thick prop roots (X 0.6); 6, habit of upper part of 

plant (X 0.6); c, enlargement of section of blade to show transverse veinlets; 

d, ligule, with twisted pseudopetiole (X 4); e, pseudopetiole showing twisting 

at summit (X 2); inflorescence showing point of disarticulation from 

peduncle (X 0.6); g, enlargement of surface of female glumes to show 

uncinate macrohairs. All drawings based on Bahkrzshnan 620, from Sri 

Lallkd. 
NUMBER 65 5 
6 SMITHSONIAN CONTRIBUTIONS TO BOTANY 
NUMBER 65 7 

2016 (NY, PDA, US). GALLE DISTRICT: Hinidun-kanda, 

Jayasuriya et al. 1795 (PDA, US). DISTRICT UNKNOWN: Kekuna Ethula Mukalane, 3-2-[ 19124, de Silva s.n. (PDA); Kopa 

Kande, Marawa Kale, 28 Feb. 188 1, without collector (PDA); 

Kalugammana, J.M. Silva 46 (BM, NSW, NY). LOCALITY 

UNKNOWN: Walker [as Walk] 1404 (PDA); Walker s.n. (GH); 

C.P. 972 (BR, GH, LE, MEL, P, US). 

DIscussIoN.-Scrotochloa urceolata, the only widespread 

species in this small, recent segregate of Leptaspis, reaches 

the western limits of its range in the wet forests of southwestern Sri Lanka and southern India. Both this species and 

its relative, Leptaspis zeylanica, occur in shaded forests, 

where individuals may form clones by decumbent culms 

that root at the lower and middle nodes. Because of the 

paucity of collections from Sri Lanka it is not possible to 

give the blooming phenology of this species for the island, 

but based on African and Asian collections it appears that 

both pharoid genera exhibit a flowering peak in the local 

rainy season. 

The dispersal mechanism of Scrotochloa urceolata is quite 

specialized. The number of conspicuous or principal nodes 

in the rachis of the inflorescence is reduced to one, although 

often one or two naked, knob-like swellings are found on 

the peduncle between the uppermost foliage leaf and the 

whorl of panicle branches, indicating where additional panicle branches have been reduced and lost. At maturity the 

principal node of the inflorescence with its whorl of 

branches disarticulates from the summit of the peduncle 

(Figure Ij), and since the branches and female florets are 

covered with a dense indumentum of hooked macrohairs 

the entire structure is easily capable of adhering to animals. 

Unlike Leptaspis zeylanica, the inflated female florets are 

neither conspicuously ribbed nor brightly colored at maturity. 

The Singhalese specimens of S. urceolata at our disposal 

did not include young inflorescences or mature fruits, so 

some material from Sumatra (Bartlett 8223) and New 

FIGL'RE 2.--ScrotochIoa urceolata, dissection of spikelets: a, pair of spikelets: 

inale left, female right, on clavate pedicel (X 12); b, glumes, 1st (left) and 

2nd (right) of male spikelet (X 12); c, lemma of male spikelet (X 12); d, 

palea of male spikelet (X 18): e, andrecium with 6 stamens and pistillodium 

in center (X 12);f; 1 st glunie of female spikelet (X 12); g, 1st glume removed 

on female spikelet to show Ioung fusiform anthecium with stigmas beginning to exit through apical pore (x 12); h, 2nd glume of female spikelet, 

inner view (X 12): t, 2nd glunie of female spikelet, side view (X 12); J, 

lemma of young female spikelet covered with uncinate hairs and with 

stigmas and palea exiting through apical pore (X 12); k, tip of female palea 

enlarged (X 48): I, mature female spikelet, side view (X 6); m, mature female 

spikelet as viewed from above (X 6); n, gynecium showing the 3 subplumose 

stigmas (x 12); o, pistilodium (X 32); p, 6 staminodes at base of ovary (X 

3'2); 4, caryopsis showing broad linear hilum in groove (X 12): r, caryopsis 

showing basal embryo (X 12); s, palea of female spikelet (X 16). Drawings 

a-e and o based on Bartktt 8223, Sumatra; f-k,n,p, and s on Brass 32709, 

Kew Guinea: 1 and m on Balakrishnan 620; 9 and r on Gardner s.n. from 

Sri Lanka. 

Guinea (Brass 32709) was used to prepare portions of the 

species description and illustration. 

ANATOMY 

FIGURE 3 

(cf. Figures 7 and 8) 

DEsCRIPTIoN.-Leaf-blade in transverse section. Outline: 

blade flat, expanded, the margins somewhat reflexed; lamina thickness 175 pm. Ribs and furrows: absent, and no 

undulations associated with vascular bundles. Midrib outline: 

distinct abaxially projecting keel (Figure 3a), this representing the functionally adaxial side of blade as the pseudopetiole is twisted through 180" at its summit; symmetrical 

and semicircular or rounded in shape; no lacunae in parenchymatous ground tissue of keel. Midrib abaxial vascular 

bundles: 1 median and 2 minor vascular bundles present; 

median bundle with well-developed abaxial cap of sclerenchynia present, but with no girder linking it to the epidermis 

(Figure 3a), the fibrous tissue surrounding the phloem 

separated from the epidermis by a continuous layer of 

niesophyll cells; minor bundles also lacking girders. Midrib 

adaxial vascular bundles: 1 minor bundle, partially embedded in a thin, broad plate of sclerenchyma extending 

the width of the midrib. Vascular bundle arrangement in 

lamina: 9 first-order bundles present in leaf section, including single first-order bundle in keel. Number of third-order 

bundles between successive first-order bundles variable 

from midrib to margin: 5-7 present between midrib and 

first lateral first-order bundle, 10-1 2 separating central 

first-order vascular bundles and 5 or 6 between first-order 

bundles near margin. All bundles located in center of blade. 

Vascular bundle description: first-order bundles ovate, with 

broader side uppermost (Figure 36); lysigenous cavity present; metaxylem vessels circular, with unthickened walls, of 

about the same diameter as the outer bundle sheath cells. 

Third-order vascular bundles elongated vertically, tall, angular, and narrow; xylem and phloem tissue distinguishable. 

Vascular bundle sheaths of primary bundles: double sheath 

present. Outer sheath square, composed of 16-1 8 cells with 

straight, vertical sides (Figure 3b), entire, although adaxial 

and abaxial cells much smaller than lateral cells; no bundle 

sheath extensions present. Cells achlorophyllous, regular in 

shape and distinct from chlorenchyma cells, although virtually same size, square-shaped with straight radial and 

outer tangential walls, the walls without secondary thickening. Inner niestome sheath entire, consisting of at least 2 

layers of cells with uniformly thickened walls (Figure 3b). 

Sclerenchyma: girders not associated with vascular bundles 

but adaxial strands developed adjacent to all bundles (Figure 3b); minute abaxial strands sometimes associated with 

bundles. Thickened, lignified pairs of epidermal cells occurring throughout both epidermides, in surface view ap- 
8 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

FIGURE 3.-Leaf anatomy of Scrotochloa urceolata: a and 6, leaf-blade 

anatomy as seen in transverse section, the adaxial (downward-facing) surface 

facing up in these views; a, outline of midrib showing shape and vasculature 

(X 55): b, anatomical detail with fusoid cell shape, multi-layered mestome 

sheath and epidermal fibers in the intercostal zones visible (X 225); c and 

d, abaxial (upper) epidermis in surface view, the long axis of the leaf 

hori7ontal; c, general cellular arrangement sholcing little differentiation 

into costal and intercostal zones (X 90); a vein in located near the bottom, 

pearing as fibers (Figure 3c4, each pair enclosing a short 

or long cell; no sclerenchyma present between bundles 

except for these fibrous bands scattered throughout both 

epiderniides. Leaf margin with a small cap of fibrous tissue 

projecting into short, narrow point. Mesophyll: chlorenchyma not radiate, consisting of single layers of cells located 

immediately subjacent to both upper and lower epidermides; remainder of leaf thickness occupied by fusoid cell 

and many fibrous bands are visible in the upper portion; d, detailed 

structure of the intercostal fibrous bands showing their tapering and interconnecting ends and associated silica bodies, interference contrast, (X 225); 

e andf; adaxial (lower) epidermal structure. Note the strongly sinuous long 

cells; e, distinct stomata1 bands flanking two veins, the intercostal zones 

composed of alternating areas of files of fibrous bands and long cells (X 

9O);f; stomata1 band above vein (lower), fibrous bands and long cells (upper) 

(X 225). Based on Soderstrorn 2562 from Sri Lanka. 

cavities. Uniseriate columns of chlorenchyma connecting 

adaxial and abaxial layers of chlorenchyma cells between 

adjacent fusoid cavities. Cells of abaxial (upper) chlorenchyma layer somewhat palisade-like, vertically oriented, 

tightly packed, larger than adaxial cells; arm cells poorlydeveloped, with only relatively short and indistinct inwardfacing invaginations. Colorless parenchyma cells not present. Bullqorm cells: absent on both epidermides. Macrohairs, 
NUMBER 65 9 

prickles, minute papillae: absent on both epidermides. Abaxial 

epidermal cells: Long cells small, inflated, each with an 

individual cuticle on their outer tangential walls. Groups of 

fibrous bands occurring at regular intervals among files of 

typical long cells (Figure 3b); stomata not observed. Adaxial 

epidermal cells: intercostal long cells small, uniform in size, 

thin-walled, without distinct cuticle; groups of lignified fibrous bands interspersed among these normal long cells. 

Stomata occurring in bands on either side of vascular bundles, serving to indicate position of costal zones overlying 

the vascular bundles. 

Abaxial epidermis: Costal and intercostal zones sometimes 

difficult to distinguish in surface view, as vascular bundles 

often not connected to epidermis by sclerenchyma girders. 

Epidermal long cells: consisting of two intergrading types. 

Normal long cells elongate-rectangular (length/width ratio 

5:l; Figure 3d) with thin, often very sinuous lateral anticlinal walls and straight end walls, these grading into thickwalled, very elongate (length/width ratio over 100: I), lignified fibers with tapering ends, the latter occurring laterally in files of three contiguous cells, the central file 

containing costal-type silica bodies and small, short, thinwalled long cells, the two sandwiching lateral files of each 

group quite fibrous, exceedingly long (1.5-4 mm) and tapering, and either interlocking with another fiber or diverging into a V configuration, and making contact with 

normal intercostal long cells. Fibrous bands typically 6- 10 

between each costal zone, not continuous along leaf length 

but ending abruptly among normal intercostal long cells. 

Bulliform cells: absent. Stomata: infrequent in short, interrupted files (Figure 3c); subsidiary cells dome-shaped, sometimes with slightly flattened tops. Intercostal short cells: present only as interrupted files of silica cells interposed between 

the files of fibers in the fibrous bands; normal long cells not 

separated by short cells. Papillae: absent. Prickles: not present on specimens examined. Microhairs: none seen. Macrohairs: absent. Silica bodies: much narrower than other epidermal cells; small, horizontally elongated, round to oblong 

or somewhat dumbbell-shaped, usually single but sometimes 

paired and alternating with short to long cells between 

epidermal fibers; granules or vesicles present in all bodies. 

Costal cells: very narrow, with silica bodies present only as 

single files between epidermal fibers; of short to medium 

length and often appearing to be silicified. Files of fibers 

located below vascular bundles probably continuous along 

the whole length of associated bundle. 

Adaxial epidermis: Similar to abaxial epidermis, but with 

costal and intercostal zones well-demarcated, Stomata: occurring in bands of 3-4 cells on both sides of the costal 

zones (Figure 3e); subsidiary cells dome-shaped but appearing to be flat-topped, as stomata1 complexes are located 

below the level of the adjacent long cells (Figure 3J; stoniatal rows adjacent to one another, a single interstomatal 

long cell separating successive stomata in a file. Intercostal 

fibrous bands: present, fewer in number (5-7) than on 

abaxial epidermis, and with no fibrous cells transitional to 

normal long cells. Fibers tapering to long, sharp points, 

occasionally branching. Intercostal long cells: of normal type, 

shorter, wider, and slightly less sinuous than their abaxial 

counterparts (Figure 3c-j). 

SPECIMENS EXAMINED.-S. urceolata: Soderstrom 2562, Sri 

Lanka (US); Brass 29119, New Guinea (US). 

DIscussIoN.-The prominent fusoid cells and complex 

midrib vasculature observed in leaf cross-sections of this 

species are familiar bambusoid features, but the intercostal 

fibrous bands of Scrotochloa (Rao and Naidu, 1981; Renvoize, 1985; Figure 3) and its relatives, Leptaspis (Metcalfe, 

1960; Clifford and Watson, 1977; Palmer and Tucker, 

198 1) and Pharus (Metcalfe, 1960; Renvoize, 1985; Figure 

8) are without exact parallel in the family. Each band 

consists of lateral files of elongate, thick-walled, tapering 

fibers that invariably enclose a single central file of silica 

cells, prickles, or modified, small long cells. On the abaxial 

surface of Scrotochloa urceolata (Figure 3c) there appears to 

be a complete gradient between these fibers and typical 

thin-walled, sinuous long cells. On the adaxial surface of 

the species, however, as well as on the abaxial epidermides 

of all the Pharus species examined for this study (Figure 8), 

there is a fairly sharp demarcation between the two types. 

Thus, preliminary evidence indicates that Scrotochloa, although advanced morphologically, may be primitive with 

respect to this character. 

Genus Leptaspis 

Leptaspis R. Brown, 1810:211. 

TYPE SPECIES.-L. banksii R. Brown. 

DIAcNOSIS.-P~ants cespitose or spreading by decumbent, rooting culms; culms solid. Leaves: sheaths compressed; blades narrow and linear to broadly elliptic. Injlorescence: a long-pedunculate panicle bearing appressed or 

spreading, single or whorled, persistent branches. Spikelets: 

paired, the female large, subsessile, the male small, pedicelled. Female spikelets: sometimes subtended by a glumelike bract; true glumes 2, persistent, cuspidate; lemmas with 

fused margins, at maturity becoming bladder-like and forming a shell-shaped (cochleate) utricle, strongly 7-ribbed, 

covered with uncinate macrohairs, somewhat indurate, the 

style exiting through a lateral pore; palea narrow, longer 

than the lemma and exiting through the pore; stigmas 

subplumose. Male spikelets: glumes persistent, shorter than 

the deciduous floret; lemmas more or less tubular; lodicules 

0-3; basic chromosome number, n = 12 (Hunziker, Wulff, 

and Soderstrom, 1982). 

DISTRIBUTION.-Tropics of the Old World, from Guinea 

eastward to Madagascar, Sri Lanka, Taiwan, Australia, New 

Caledonia, and the Fiji Islands. 

SPECIES OF Leptaspis IN SRI LmKA.-Leptaspis reylanica. 
10 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Key to the Species of Leptaspis 

1. Main inflorescence branches in whorls of 3; leaf-blades 2.5-6 cm wide, glabrous; 

bract subtending 1st female glume present; Guinea, Sri Lanka, to New Guinea, 

Bougainville ........................................... L. xeylanica 

1. Main inflorescence branches borne singly at the nodes; leaf-blades 1-2.5 (-3.5) 

cm wide, glabrous or puberulent beneath (adaxially); bract subtending 1st female 

glume typically absent ........................................... 2 

2. Leaf-blades lanceolate, (1.5-) 2-3 (-3.5) cm wide, puberulent beneath; Taiwan, 

Indonesia to New Caledonia, Australia ..................... L. banksii 

2. Leaf-blades linear, about 1 cm wide, glabrous; Fiji Islands ... L. angustyolia 

Leptaspis zeylanica 

Leptaspis zeylanica Nees ex Steudel, 1853:8. [Type: Sri Lanka. Neotype, 

here designated: Sri Lanka, without locality or collector, C.P. 896, B!] 

Leptaspis cochleata Thwaites, 1864:357. [Type: Sri Lanka, Central Provinces. Lectotype [chosen by C.C. Mez in 19221: Sri Lanka, without locality 

or collector, C.P. 896, B!] Hooker f., 1900:191; Senaratna, 1956:22; 

Bor, 1960:617, fig. 73. 

Leptaspis conchzjera Hackel, 1887:211-212, pl. G, fig. A. [Type: Sao Tome, 

“prope IMorros de Monte Cafe ad 850 m (Moller) et prope Mongo ad 

480 m (Moller); Angolares (F. Quintas).” Holotype, Moller and Quintas 

148, M’, not seen: isotype, K, not seen; fragment of holotype, US! sheet 

no. 81844.1 

Leptaspis comorensis A. Camus, 1924:513. [Type: Comoro Islands, Humblot 

321. Holotype, P!; isotypes, BM!, K, not seen.] 

MORPHOLOGY 

FIGURE 4 

DESCRIPTION.-PlantS: with shallow rhizomes, the 

strongly ribbed internodes 1-6 cm long, the sheathed nodes 

each bearing a thick, hard, long, adventitious (prop) root, 

this bearing fibrous roots: rhizome continuous into the 

aerial axis (culm) of the plant, or new culms sometimes 

borne from a decumbent node. Culms: up to 1 m tall, covered 

by overlapping sheaths. Leaves: sheaths elongate, glabrous, 

strongly ribbed, narrowed to the ligule and continuous with 

the pseudopetiole, sparingly tessellate on the outer surface, 

glabrous, the ribs of the sheath continuous with those of 

the abaxial face of the blade; blades oblong-lanceolate, 10- 

20 cm long, 2.5-5 cm wide, flat, narrowed at the base into 

a pseudopetiole 1/~~~-1/~-) the length of the blade, the apex 

acute: upper (morphologically abaxial) surface glabrous except for the pilose adaxial surface of the pseudopetiole, the 

midvein slightly elevated, green, strongly ribbed, the primary veins emanating from it along the lower half, tessellate; lower (morphologically adaxial) surface glabrous, 

strongly tessellate, the broad midvein flush with the epidermis, stramineous, smooth, shiny; ligule about 0.25 mm long, 

membranous, densely ciliate on the abaxial surface. Peduncle: exserted, 5-10 cm long, densely covered with uncinate 

hairs. Inflorescence: a narrowly ovoid panicle to 30 cm long, 

the rachis strongly angled and covered with uncinate macrohairs, bearing whorls of branches at the nodes: primary 

branches ascending or held at an acute angle or sometimes 

elongate, lax, and horizontally positioned, covered with a 

fine mat of uncinate hairs, 3 (-5) branches to about 15 cm 

long radiating from the lower nodes and fewer and shorter 

branches from the upper nodes, pulvinate at the base on 

the upper surface, the branches not disarticulating at maturity. Branchlets bearing spikelets sometimes subtended by 

a deciduous, narrow, glume-like bract about 1 mm long 

(Figure 4e, arrow), terminating in a male spikelet and bearing about 1-2 mm below it a subsessile female spikelet. 

Female spikelets: subtended by a deciduous, lanceolate-triangular glume-like bract 3-4 mm long placed below and 

slightlv lateral to the 1st glume and separated from it by a 

short internode: glumes 2, subequal, broadly ovate with a 

cuspidate tip, about 2-2.5 mm long, 1(-3)-nerved, persistent, becoming horizontal and relatively indistinct under the 

expanded lemma; floret 4-3 mm long, ovate and symmetric 

when young, purplish-brown, at maturity greatly inflated, 

cochleate, the surface stramineous, pinkish, or purplish and 

covered with a dense mat of small uncinate hairs, strongly 

7-nerved, the nerves elevated: palea about half the length 

of the lemma, broader at the base and flat, becoming sulcate 

above between the 2 keels, bifid at the apex, glabrous; ovary 

glabrous; style 1, stigmas 3, subplumose; andrecium not 

seen in material examined; caryopsis not seen. Male spikelets: 

slightly overtopping the female, terminating the entire inflorescence, about 3.5 mm long, ovoid, purplish-brown, the 

glumes broadly ovate, narrowed abruptly to a cuspidate tip, 

subequal, about 1.2 mm long, glabrous, 1-nerved, persistent: lemmas broad, somewhat inflated, 3-nerved, covered 

with minute dark brown hairs, 3.3-3.5 mm long; palea 

FIGURE 4.--Leptaspis zeylanica: a, habit of plant showing decumbent culm 

with prop roots (X 0.6); 6, upper leaves of culm (X 0.6); c, inflorescence, 

showing primary branches in whorls of 3 (X 0.6); d, branches of inflorescence enlarged to show pulvini (X 5.5); e, pair of young spikelets (X 1 l), 

male left, female, right; note glume-like bract subtending the 1st female 

glunie, and second bract (arrow) subtending the branchlet hearing the malefemale spikelet pair;J andreciuni of 6 stamens with pistillodium in center 

and palea extending behind (X 23); g, mature spikelet pair, male on left, 

feniale with inflated lemma on right (X 7.5). Drawings a, c, and e based on 

Gardner s.n., Matale, Dec 1846, C.P. 896; b, d,J and g on Sumithraarachchi 

602, both from Sri Lanka. 
NUMBER 65 11 
12 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

shorter than the lemma, about 2.6 mm long, linear, bifid at 

the apex, membranous; lodicules 3, the anterior pair broad, 

rounded, glabrous, nerveless, about 0.3 mm long, the posterior reduced; stamens 6, the anthers orange-yellow, 2.1- 

2.6 mm long, basifixed, the filament attached to the connective at the lower Y5 of the anther; rudimentary gynecium 

not seen. 

SPECIMENS EXAMINED.-MATALE DISTRICT: Gammaduwa, Alston 670 (PDA); C.P. 896 (PDA), 0. C. [?] 1045 

(PDA); Matale, C.P. 896 (PDA); Gardner s.n., Dec 1846 

(PDA); C.P. 896 (US). KANDY DISTRICT: Hantane, Gardner 

1045 (NY); Boyagoda Kanda, near Galagedera, 7’23’N, 

80” 30’E, Sumithraarachchi 602 (B, PDA, US). LOCALITY 

UNKNOWN: C.P. 896 (BM, BR, LE, P); anno 1827-1830, 

Macrae 810 (BM). 

DIscussIoN.-Leptaspis zeylanica has one of the widest 

ranges of any herbaceous bamboo, extending nearly halfway around the globe (160’ of longitude), from the west 

coast of Africa to the Solomon Islands. The genus is unusual 

in the tribe in that neither the inflorescence nor its branches 

disarticulate at maturity, although the mature female florets 

readily detach from the glumes and adhere to clothing and 

presumably also fur and feathers. Label data of collectors 

on specimens from outside of Sri Lanka indicate that these 

shell-like, utriculate diaspores often have a showy, pink or 

purple color at maturity, and that the prominent ribs are 

white or dark-colored. Clearly, animal interactions with this 

grass must be complex, and our understanding of the subject would benefit from further study. 

Very few good Sri Lanka collections of this species were 

available for study. Most male florets had already fallen 

from our material, and it was difficult to find any with the 

stamens still present. Measurements of these organs were 

therefore taken from those of a plant collected in Cameroon 

(Mildbraed 7856, US). 

Steudel (1 853) described Leptaspis zeylanica as having 

“oblong leaves and pseudopetioles pubescent below toward 

the midrib, variable in having a composite raceme with 

subrotund, cuspidate valves [female florets] and a simple 

raceme with ovate-acuminate valves” [translated from the 

Latin]. In the same work he also described L. manillensis 

(with a “verticilled panicle” and “oblong valves”), since 

shown to be the same as Scrotochloa (Leptaspis) urceolata, 

with which the author was evidently not familiar. The two 

genera of Ceylonese Phareae are quite similar vegetatively 

in that both have oblong leaf blades that narrow below into 

twisted pseudopetioles. In S. urceolata, however, the pseudopetioles are completely glabrous, while in L. zeylanica 

they are densely pubescent on the inner surfaces. Also, the 

female florets in this species are subrotund, not oblong as 

in Scrotochloa, and the inflorescence does resemble a “composite raceme,” whereas Scrotochloa has an umbelliform 

panicle. It is evident that Thwaites (1 864) described Leptaspis cochleata because he mistakenly considered L. zeylanica 

to be synonymous with Scrotochloa (Leptaspis) urceolata. Leptaspis zeylanica Steudel thus takes precedence over the later 

name of Thwaites, and we here designate the Berlin specimen from Sri Lanka, labelled “C.P. [Ceylon Plants] 896,” 

to serve as the neotype. This specimen has also been chosen 

as the type of Leptaspis cochleata Thwaites by C.C. Mez in 

March 1922, as indicated by his annotation of the Berlin 

specimen. Sheets marked “C.P. 896” are found in many 

European herbaria, but since the “C.P.” series numbers 

were essentially species numbers it is impossible to be certain 

that they all come from the same locality. 

ANATOMY 

No preserved anatomical material of Leptaspis zeylanica 

was available for this study, but based on the descriptions 

and illustrations of African material of this species by Metcalfe (1 960), Jacques-Felix (1 962), Palmer and Tucker 

(1981), and research in progress, the leaf anatomy of this 

taxon appears to be quite similar to that of the species of 

Scrotochloa (Figure 3) and Pharus (Figures 7 and 8) examined. In transverse blade sections L. zeylanica is hardly 

distinguishable from its sister genera, but in epidermal views 

it rather surprisingly bears a closer resemblance to Pharus 

than it does to Scrotochloa. In common with all Pharus 

species, but unlike Scrotochloa, the abaxial (lower) blade 

surface of L. zeylanica exhibits prominent inflated interstomatal cells (see Palmer and Tucker, 1981), and the silica 

bodies are consistently dumbbell-shaped. As is typical of 

pharoid grasses, intercostal fibrous bands are prominent on 

at least one epidermis. 

Tribe STREPTOGYNEAE 

STREPTOGYNEAE C.E. Hubbard ex Calderon and Soderstrom, 1980: 18. 

TYPE GENus.-streptogyna P. Beauvois. 

DIAcNosIs.-Forest grasses forming cespitose clumps or 

spreading by rhizomes. Leaves: blades linear-lanceolate to 

broadly lanceolate, narrowed below to a pseudopetiole-like 

base, the nerves parallel, transverse veinlets not manifest, 

the midvein and secondary nerves clearly manifest on the 

lower surface; outer ligule present as a small hard rim with 

irregular margins; inner ligule short, membranous. Znjlorescence: an erect one-sided raceme. Spikelets: several-flowered; 

florets hermaphrodite, the upper ones reduced and not 

fertile, disarticulating between the fertile florets above the 

glumes, each floret falling attached to the extended curved 

rachilla segment above it; glumes 2, persistent, the lower 

shorter than the upper, the upper convolute and enclosing 

the floret at its base; lemmas narrow, elongate, awned, 

many-nerved; paleas strongly 2-keeled, sulcate between the 

keels; lodicules 3; stamens 2 or reportedly 3; ovary with a 

long style and 2 or 3 spiraling stigmas, these becoming 
NUMBER 65 13 

hardened and persistent, intertwined at maturity with the 

stigmas of other florets in the same spikelet and inflorescence; fruit a linear caryopsis, with a narrow hilum equaling 

its length; embryo small, basal. Basic chromosome number, 

n = 12 (Tateoka, 1958b). 

DIsTRIBuTIoN.-~ne genus of two species occurring in 

the tropics of Latin America, Africa, southern India, and 

Sri Lanka. The range of Streptogyna is strikingly paralleled 

by that of the centothecoid genus, Orthoclada. 

This is the only genus of herbaceous bamboos that is 

native to the tropics of both hemispheres and studies are 

underway to determine the relationships of the species to 

each other and to the other herbaceous bamboos. 

Genus Streptogyna 

Streptogyna Palisot de Beauvois, 18 12:80. 

TYPE SPECIES.-S. crinitu P. Beauvois. 

SPECIES OF Streptogyna IN SRI LANKA.-Strt?ptOgynU crinita. 

Key to the Species of Streptogyna 

Stigmas 2; plants rhizomatous; leaf-blades (lo-) 15-36 mm wide; callus of floret 

pilose; Paleotropical ........................................ S. crinita 

Stigmas 3; plants cespitose; leaf-blades 8-16 (-24) mm wide; callus of floret glabrous; 

Neotropical ................... ...................... S.americana 

Streptogyna crinita 

Streptogyna crinita Palisot de Beauvois, 1812:80 + pl. 16, fig. 8. [Type yide 

Hubbard, 1956): Nigeria, Palisot de Beauvois s.n. Holotype: P, not 

seen.] Thwaites, 1864:374; Bor, 1960:649. 

Streptogym gerontogaea Hooker f., 1900:301-302. [Type yide Hubbard, 

1956): Sri Lanka, without locality or collector, C.P. 922. Holotype, K, 

not seen.] Senaratna, 1956:34. 

MORPHOLOGY 

FIGURE 5 

DESCRIPTION.--CU~~~: erect 75-100 cm tall, each representing the aerial extension of an upturned sympodial 

rhizome, the culm itself producing at its base 1-3 additional 

rhizomes to 25 cm long, these with short internodes about 

1 cm long covered by the overlapping sheaths. Leaves: 

evenly distributed along the culm, the sheaths not overlapping; sheaths glabrous, strongly ribbed, extending upward 

along both sides of the blade pseudopetiole and contiguous 

with the inner ligule; blades up to 26 cm long, 2.5 cm wide, 

broadly lanceolate and tapering at both ends, acute at the 

tip, narrowed below to a pseudopetiolate base, narrower 

than the summit of the sheath, 6 primary nerves present on 

either side of the midrib; upper blade surface pale green, 

with scattered spinelike hairs, lacking manifest transverse 

veinlets, the midrib not pronounced; lower surface darker 

green than the upper, glabrous, transverse veinlets manifest, the midvein conspicuous, thick, shiny; outer ligule 

about 0.5 mm long, indurate; inner ligule about 1.2 mm 

long, the upper margin erose, ciliate on the abaxial (outer) 

surface, glabrous on the adaxial surface. Inflorescence: terminating the culm, racemiform, 20-22 cm long, secund, 

containing 20-25 overlapping spikelets; axis appressed-pubescent, rounded on the back, with the outer surface flat 

or grooved; rachis slightly twisted, bringing all spikelets into 

alignment. Spikelets: pale green, 4- or 5-flowered, slightly 

laterally compressed, the first floret most developed, with 

reduction upwards; 1st glume about 12 mm long, linearlanceolate, glabrous, 3-nerved, transversely veined, attached to the side of the thickened pedicel that supports the 

second glume; 2nd glume about 26 mm long, elliptic-lanceolate, glabrous, 17-nerved, the nerves of various thicknesses, not all extending the length of the glume, with 

numerous transverse veinlets and an antrorsely scabrous 

awn 1-2 mm long; lemma of lowest floret about 19 mm 

long, lanceolate, firm and thick except for the broad scarious margins, 9-nerved, the two halves tightly folded, sparingly appressed-pubescent on the lower half, the base extended beyond the attachment of the lemma and palea into 

a pubescent stipe (glabrous in the upper reduced florets), 

the midnerve thickening above into an antrorsely scabrous 

awn about 15 mm long, this becoming elongated and coiled 

at maturity; palea about 13 mm long, glabrous and bowedout below, narrowed above and puberulent, strongly 2- 

keeled, the keels close together and grooved between them; 

rachilla internodes elongated, glabrous, curved, with an 

oblique apex and base; lodicules 3, thin, narrowly obovate, 

glabrous, with a few tiny hairs at the tip, the anterior pair 

1.6-2.4 mm long, 1-5-nerved, the posterior one a little 

shorter, 1.6-1.8 mm long, 1-3-nerved. Andrecium: stamens 

2, the filament weak and ribbonlike, the anthers yellow, 

basifixed. Gynecium: ovary fusiform, long-ciliate on the upper third and lower part of the style; style long, flattened, 

with sparse appressed hairs; stigmas 2, strongly retrorsely 

barbed above, the barbed portions elongating and coiling 

with age, eventually becoming entangled with each other 

and with the awns of the lemmas; fruit a caryopsis about 15 

mm long, narrow, elongated, slightly tapering, the ciliate 

summit of the ovary persistent at its apex; hilum narrow, 

linear, extending the full length of the fruit; embryo about 

'/I I the length of the caryopsis. 
14 SMITHSONIAN CONTRIBUTIONS TO BOTANY 
NUMBER 65 15 

SPECIMENS EXAMINED.-KURUNEGALA DISTRICT: DOlukanda, Senaratna 2700 (PDA). MATALE DISTRICT: Matale, 

Dec 1846, Gardner s.n., C.P. 922 (PDA). COLOMBO DISTRICT: 

Henaratgoda, 3 Jan 1881, Ferguson s.n. (PDA). MONERAGALA DISTRICT: Buttala to Sirigala, 3 Mar 1907, Rock s.n. 

(PDA). 

DrscussIoN.-The stigmas of this genus are unusual, and 

perhaps unique in the grasses, in that they continue to grow 

after performing the usual function of pollen reception. S. 

crinita, especially, is unusual in that the stigmas develop 

hardened, retrorse barbs. The filaments of the stamens are 

weak and ribbon-like, and field observations will be needed 

to determine whether the anthers are exserted or not. 

Although only two stamens were observed in the florets of 

the material studied, both Bentham (1 88 1) and JacquesFklix (1962) report that this genus may also have three 

stamens. The description and illustration of the caryopsis 

\$.as based on a specimen from Cameroon (Africa) (Buesgen 

Hubbard (1956) pointed out that the name S. crinita had 

long been misapplied to the American species, and that 

Hooker (1900), unaware of this, renamed the Ceylonese 

species S. gerontogaea, basing that epithet on a Kew specimen 

labelled C.P. 922. Realizing that S. crinita applied to the 

Asiatic specimens and that the American species was without 

a name, Hubbard therefore described the latter as S. americana. As in the case of Leptaspis zeylanica, other sheets 

labelled “C.P. 922” cannot unequivocally be considered to 

represent type material. 

At maturity the antrorsely scabrous lemma-awns and all 

spikelets in the inflorescence are collectively bound together 

by the retrorsely barbed stigmas, which coil around each 

other. The entire mass then has the potential to disarticulate 

and adhere to passing forest animals. The pointed callus of 

the lemma and the persistent rachilla internode may also 

facilitate adherence to fur or feathers. The survival of 

Streptogyna in both hemispheres may have been due in part 

to this epizoochorous dispersal mechanism. The two species 

530). 

FIGURE 5.--Streptogyna crinita: a, base of plant showing sympodial habit of 

rhi7omes (X 0.6) b, leafy portion of mature culm terminating in young 

inflorescence (X 0.6); c, mature inflorescence (X 0.6); d, ligular region, 

showing inner and outer ligules (X 7); e, young spikelet (X 2.5);J glumes 

(X 3.5); g, spikelet without glumes (X 3.5); h, section of lemma awn showing 

antrorse scabrosity (X 30); t, base of lower fertile floret and succeeding 

rachilla segment (X 11); j, palea of fertile floret with succeeding rachilla 

segment (X 7); k, lodicules, at left the posterior lodicule and others the 

anterior lodicules (X 1.5); I, andrecium of 2 stamens with ribbonlike filaments and gvneciuni showing the hairy ovary and style and 2 stigmas (X 7); 

m, section of stigma showing retrorse scabrosity (X 30); n, caryopsis, showing 

small embryo at base and persistent hairy apex of ovary (X 5.5); 0, caryopsis, 

showing narrow, elongated hilum, and persistent hairy apex of ovary (X 

5.5). Drawing a based on Rock s.n., 8 Mar 1907, Sri Lanka; b-ion Senaratna 

2700, Sri Lanka; j, I, and m on Trimen s.n., Henaratgoda, 3 Jan 1881, Sri 

Lanka; k on Gardner sn., Dec 1826, Sri Lanka; n and o on Buesgen 530, 

Cameroon, Africa. 

are so similar in details of inflorescence and spikelet structure that they cannot be separated into two genera, and it 

is not obvious which taxon is more primitive. Studies of the 

anatomy and morphology of both species are underway. 

ANATOMY 

FIGURE 6 

DEScRIPTION.-Leafblade in transverse section. Outline: 

blade flat to broadly U-shaped with margins curved slightly 

upwards. Ribs and furrows: slight ribs and furrows present 

(Figures 64). Midrib outline: keel present, triangular, with 

complex vasculature; abaxially projecting. Midrib abaxial 

vascular bundles: large median bundle present, this connected to the epidermis by an anchor-shaped girder of 

sclerenchyma; two additional first-order bundles present, 

these connected to the epidermis by smaller sclerenchyma 

girders; smaller bundles 8, 5 of these variously oriented and 

embedded in the mass of fibrous tissue (Figure 6e) supporting the median bundle. Midrib adaxial vascular bundles: 

large first-order bundle present, this with a cap of fibers 

only barely touching the epidermis; minor bundles 2, without sclerenchynia girders. Vascular bundle arrangement in 

lamina: first-order bundles 13; third-order bundles 6 or 7 

between consecutive large bundles; all bundles located 

slightly towards the abaxial side of blade. Vascular bundle 

description: first-order bundles ovate with broadest side 

adaxial; phloem surrounded by fibers; lysigenous cavity and 

protoxylem vessel present; metaxylem vessels thickened, 

circular, with diameters greater than the outer bundle 

sheath cells; third-order bundles vertically elongated, elliptical; phloem easily distinguishable. Vascular bundle sheaths: 

outer bundle sheaths of first-order vascular bundles ovoid, 

consisting of about 20 cells, with narrow adaxial and wide 

abaxial interruptions (Figure 6b,fl; bundle sheath extensions absent; chloroplasts absent, the cells thus distinct from 

chlorenchyma cells; inner (mestome) sheath of first-order 

vascular bundles complete; cell layers 2 or 3 (Figure 6bf), 

the cells with uniformly thickened walls; outer sheath surrounding third-order bundles entire, consisting of 7- 1 1 

cells, a distinct gradation in size occurring between the large 

lateral outer bundle sheath cells and the very small adaxial 

cells, which are about the same size as inner sheath cells 

(Figure 66). Sclerenchyma: small trapezoidal adaxial girders 

developed in association with all vascular bundles. Mesophyll: 

arm cells relatively conspicuous (Figure 6f); no tendency 

toward a palisade-like arrangement of adaxial chlorenchyma cells displayed; chlorenchyma subjacent to adaxial 

epidermis 2 or 3 cell layers thick, and that subjacent to 

abaxial epidermis 1 or 2 layers thick; fusoid cells distinct 

and clearly demarcated, short and ovoid in shape, successive 

fusoid cells separated by 3 or more arm cells; colorless 

parenchyma cells absent. Bull$orm cells: present on adaxial 
16 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

FIGURE 6.-Leaf anatom) of the genus Streptogyna: a-d, S. americana: a, 

outline of midrib showing shape and complex vasculature of the keel (X 

60); b, anatomical detail showing fusoid cell shape and multi-layered inner 

bundle sheath of first-order vascular bundles (X 240); c, abaxial epidermis 

showing poorly differentiated costal zones (X 150); d, abaxial epidermis 

illustrating fiber-like long cells in centre of intercostal zones and absence of 

papillae and epidernial appendages (X 240); e andf, S. crinita: e, outline of 

leaf blade in region of keel (X 60); J detail of leaf blade anatomy with 

double inner bundle sheath (X 240). Streptogym americana from Soderstrom 

and Sucre 1906, Brazil; S. crinita from Linder 1012, Liberia. 

surface only, in discrete, fan-shaped groups between all 

vascular bundles, occupying about one-third of the blade 

thickness, each group consisting of 3 or 4 cells with the 

outer tangential walls shorter than the inner walls; lateral 

walls straight (Figure 6bf). Adaxial epidermal cells: bulliform 

cells present; outer tangential wall of all epidermal cells, 

except bulliform cells, covered by distinct, continuous cuticle; macrohairs, prickles, and papillae not seen. Abaxial 

epidermal cells: bulliform cells absent; outer tangential wall 

with continuous cuticle; macrohairs and papillae absent; 

prickles present. 

Abaxial epidermis. Intercostal long cells: markedly elongated, particularly in center of intercostal zones; cells somewhat fiber-like, with tapering ends and much more than 3 

times longer than wide (Figure 6c,d); side walls parallel, end 

walls vertical; horizontal anticlinal walls only slightly undulating; shape of all abaxial long cells (both costal and intercostal) remarkably similar and constant throughout abaxial 
NUMBER 65 17 

epidermis; most long cells separated from horizontally adjacent neighbors by single short cells or silico-suberose 

couples; interstomatal cells with relatively sinuous walls. 

Stomata: 4 or 5 irregular horizontal files of stomata present 

on either side of costal zones, some files present in adjacent 

files of intercostal long cells, the two stomatal zones in each 

intercostal zone separated by up to 10 files of fiber-like long 

cells; individual stomata in a file separated by 1 or 2 interstomatal long cells, these elongated and where adjoining 

one another separated by paired short cells (Figure 6d); 

subsidiary cells uniformly low-domed-shaped, their papillae 

small, indistinct or absent. Intercostal short cells: paired or 

rarely solitary, present between virtually all intercostal long 

cells; cork cell tall and narrow, with a somewhat crenate 

outline; silica body saddle-shaped but vertically elongated. 

Papillae: absent except for minute and indistinct papillae 

present only on subsidiary cells. Prickles: none seen. Microhairs: none seen. Macro-hairs: absent. Silica bodies: vertically 

elongated, tall saddle-shaped; costal and intercostal silica 

bodies of similar shape, of same width as associated long 

cells; invariably associated with cork cells, these cork-silica 

cell pairs separated by elongated long cells. Costal zones: 

very narrow, 1-3 cells wide, consisting of parallel-sided, 

elongated long cells with slightly thickened walls. 

Adaxial epidermis: Similar to abaxial epidermis, except 

that 3 or 4 files of colorless, equidimensional, hexagonal 

bulliform cells are present in center of intercostal zones, 

these angular, straight-walled, and interlocking with one 

another. A few small prickles present on edges of files of 

bulliform cells. 

SPECIMEN EXAMINED.-S. crinita: Linder 101 2, Liberia 

(K). 

DrscussIoN.-The multi-layered mestome or inner 

sheath observed in Liberian material is also clearly illustrated by Jacques-Felix (1 962) for African S. crinita, but 

Tateoka’s (1958a) drawing of a Sri Lanka specimen shows 

only a single-layered inner sheath, and the multi-layered 

condition is not mentioned by Metcalfe (1960), who also 

examined the Linder collection cited above, or by Renvoize 

(1 985), who studied material from Ghana. 

The structure of the adaxial chlorenchyma tissue is not 

palisade-like in either of the specimens we examined (Figure 

6b,f), or in the drawings of S. crinita published by Tateoka 

(1 958a) and Jacques-Felix (1 962). The unfixed specimen of 

S. crinita examined in this study had chlorenchyma with 

distinct arm-like invaginations and closely resembles the 

condition shown in the plate of Jacques-Felix (1 962). The 

Ceylonese specimen studied by Tateoka (1 958a) apparently 

lacks well-developed arm cells, but perhaps the drawing 

may simply lack this detail. It is possible that Asian and 

African S. crinita specimens, then, show slight but distinct 

differences in arm cell development and in the nature of 

the inner bundle sheath; clearly, more material of this 

species and its New World congener needs to be examined 

with regard to these characters. The Brazilian specimen of 

S. americana (Figure 66) studied lacks distinct arm cells and 

its adaxial and abaxial chlorenchyma cells are only two 

layers and one layer thick, respectively. 

Bulliform cell groups are well developed in Streptogyna 

and the fusoid cavities of both species are fully developed 

across the full width of the leaf. This led Metcalfe (1 956) 

to suggest bambusoid affinities for the genus. 

The epidermal structure of Streptogyna is of particular 

interest in that it differs somewhat from the typical bambusoid configuration. The extremely long, fiber-like cells 

in the centers of the abaxial intercostal zones of S. americana 

(Figure 6c) have not been referred to before; the epidermis 

illustrated by Jacques-Felix (1962) for S. crinita does not 

appear to possess this type of cell (although the drawing 

does not include a full intercostal zone), and Renvoize’s 

(1 983) drawing of this epidermis shows elongate cells with 

sinuous walls. In transverse sections of S. americana examined (Figure 6a) there is no indication that these cells are 

actually fibers; indeed, they closely resemble normal long 

cells when viewed in this plane. This unusual cell type may 

conceivably indicate a relationship with the pharoid grasses 

and it will be interesting to determine whether they occur 

consistently in one or both Streptogyna species. 

Streptogyna possesses few epidermal appendages, although 

prickles have been reported in S. crinita by Metcalfe (1 960), 

Jacques-Felix (1 962), Palmer and Tucker (1 98 l), and Renvoize (1 985), the last author illustrating them as abundant 

on the abaxial epidermis. In the present study no prickles 

were observed on the abaxial epidermis of S. crinita, although a few were present on the adaxial surface. Very 

scattered delicate, spinelike macrohairs are present in the 

leaves of many African collections (e.g., Fosberg 40539, 

Ivory Coast, US), but the absence of microhairs and distinct, 

minute papillae in the genus is supported by all workers 

who have studied its anatomy. This condition is rare in 

bambusoid grasses. 

Phylogenetic Considerations 

MORPHOLOGICAL AND ANATOMICAL DIAGNOSIS OF THE 

BAMBUSOIDEAE 

Given the importance of leaf anatomy in delimiting the 

graminoid subfamilies and the broad sense in which the 

Bambusoideae is now interpreted, it is difficult to present 

an unambiguous morphological diagnosis of the group. 

Soderstrom’s (1 98 1) characterization of the main morphological features of the subfamily, excluding the Oryzeae, 

includes the following very general tendencies that are 

found in most tribes: Leaf blades broad, transverselyveined, pseudopetiolate; pseudospikelets present; lodicules 

3; stamens 3 or 6; stigmas 2 or 3; fruit a caryopsis with a 

long, linear hilum and small embryo; and seedling with 
18 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

coleoptile not elevated from the caryopsis, the first seedling 

leaves bladeless. We emphasize that there are many exceptions to even this skeletal summary of bambusoid morphology, particularly in outlying tribes such as the Oryzeae and 

Phareae. 

Anatomical characteristics of the leaf-blade are now 

widely recognized as being very important in the diagnosis 

of the five subfamilies of the Poaceae that are now generally 

accepted by most agrostologists. Each of these subfamilies 

can be characterized by a unique combination of leaf blade 

anatomical features possessed by their constituent representatives, and the delimitation of subfamilies is now firmly 

based upon differences in leaf blade anatomy (Watson and 

Clifford, 1976; Clifford and Watson, 1977; Renvoize, 

1981). The bambusoid type of leaf anatomy has been defined as follows by Metcalfe (1956, 1960), Calderon and 

Soderstrom (1 973), Soderstrom (1 981), and Renvoize 

(1 98 1) and further elaborated upon by our own work. 

Outline: leaf-blade flat and expanded, the two halves of 

the lamina often asymmetrical about the midrib, this asymmetry evident in transverse section by the S-shaped midrib 

and the difference in shape of the two margins, which differ 

in the degree of tapering as well as in the degree of development of the lateral adaxial ribs. 

Transverse veinlets (or commissural veins) usually present 

and conspicuous, connecting the parallel, first- and thirdorder longitudinal vascular bundles. 

ibfidribs invariably well developed and conspicuous, often 

in the form of prominent, asymmetrical keels with colorless 

parenchyma ground tissue and containing complex vascular 

systems, with bundles located in two planes close to both 

the abaxial as well as the adaxial epidermides; keel bundles 

usually embedded in and supported by elaborate systems of 

sclerenchyma tissue. 

Bundle sheaths always double; outer (parenchyma) sheath 

composed of a single layer (at least laterally) of large cells 

with few chloroplasts; inner (mestome) sheath conspicuous, 

one or usually two cell layers thick, the cells small and with 

uniformly thickened walls. 

Chlorenchyma cell arrangement without exception nonradiate, with a lateral cell count greater than four; the 

anatomy is, therefore, non-Kranz, with the C3 photosynthetic pathway being operational (Brown, 1977); chlorenchyma always composed of arm cells arranged in a few 

horizontal layers adjacent to and parallel with the upper 

and lower epidermides; chlorenchyma with invaginations or 

arms projecting inwards towards the fusoid cells or fusoid 

cell cavities; fusoid cells and fusoid cell cavities located on 

either side of each vascular bundle, enclosed between the 

adaxial and abaxial layers of arm cells and in contact with 

the outer bundle sheaths; adjacent fusoid cells separated by 

narrow columns (1-several cells wide) of arm cells. 

Epidermal structure complex, far from uniform throughout the subfamily, with many different types of epidermal 

appendages present. 

Long cells uniform in type with thickened, usually very 

sinuous anticlinal walls; in outline, the cells elongate-rectangular with parallel side walls; bulliform cells equidimensional, hexagonal, typically present on adaxial epidermis. 

Stomata with subsidiary cells either dome-shaped or triangular; shape of subsidiary cells often obscured by overarching papillae. 

Papillae common in most tribes, often abundant on epidermal long cells; many small, cutinized papillae typically 

occurring on each cell, these often overarching the stomata. 

Microhairs usually present, finger-like and bicellular; both 

cells elongated, more or less equal in length, uniform in 

diameter, the distal cell with a rounded apex and not 

tapering to a point. 

Silica bodies variable in shape and usually transversely 

elongated in the direction of the long axis of the leaf; tall, 

saddle-shaped types predominate but cross-shaped, olyroid 

types, and horizontally-elongated dumbbell-shaped types 

also occur. 

Short cells paired, or sometimes in short rows. 

RELATIONSHIPS OF THE PHAREAE TO THE BAMBUSOIDEAE 

Until the past quarter-century there has been little taxonomic consensus on the correct subfamilial placement of 

the pharoid genera. Some early authors, perhaps noting the 

rice-like appearance of the female spikelets of several common species of Pharus, placed the group in the Oryzeae 

(Kunth, 1835). Bentham (1881) stressed the similarity of 

the indurate female lemmas of Pharus and Olyra to the 

panicoid grasses and therefore placed them hesitantly in the 

Paniceae. Following the anatomical studies of Brandis 

(1 907) and especially Metcalfe (1 956, 1960), however, it 

became apparent that the Phareae were more closely related 

to the true bamboos than to any other grass group, and 

later workers (Calderon and Soderstrom, 1980) have placed 

the tribe in the Bambusoideae, or near to the bamboos in 

the Olyroideae (Pilger, 1954; Jacques-Felix, 1962). 

MoRPHoLoGY .-In gross morphology, all three genera 

of pharoid grasses resemble the core group of the bamboo 

subfamily in possessing pseudopetiolate, usually broad leaf 

blades with evident transverse veinlets. Those species with 

very narrow blades lacking evident commissural veins (Leptaspis angustfolia, certain races of Pharus lappulaceus, and 

Scrotochloa tararaensis) are clearly specialized taxa that have 

been derived from broad-leaved ancestors. 

The Phareae differ from all other bambusoids in their 

obliquely veined, inverted leaf blades. Too much emphasis 

must not be placed on these features, however, since oblique 

venation has been independently derived in at least one 

other subfamily of grasses. Setaria paniculijiera and related 

species in the Panicoideae have this type of venation, yet 

they otherwise fit comfortably into a genus and subfamily 

with parallel-veined leaves. Maclurolyra tecta has semi-inverted leaf blades (Calderon and Soderstrom, 1973), yet 
NUMBER 65 19 

other morphological and anatomical data clearly place the 

genus in the Olyreae. 

In critical details of spikelet structure, too, the Phareae 

resemble the bamboo core group in possessing six stamens 

and three stigmas, and at least some species have male 

spikelets with three lodicules, though the latter structures 

are atypical in their lack of hairs and vascular bundles. The 

fruit in the tribe is a caryopsis with a long, linear hilum and 

a small embryo, again features that are typically bambusoid, 

although the first seedling leaf is usually not transitional in 

size to the adult blades (Soderstrom, 1981), and so in this 

respect does not resemble a typical bamboo. Sections of the 

embryos of pharoid genera have not been made for this 

study, but Reeder (1 962) reports that Pharus, at least, has 

an embryological formula that does not differ from the four 

genera of woody bamboos that he investigated. Hunziker, 

Wulff, and Soderstrom (1 982) report a basic chromosome 

number of n = 12 for the group, again consistent with the 

Bambusoideae. 

of comparison with Scrotochloa and Leptaspis, and to illustrate the cohesiveness of the Phareae, we also examined 

blade cross-sections and epidermides of several species of 

Pharus (Figures 7 and 8). 

In transverse section, the leaf outline of the pharoid 

grasses is symmetrical about the midrib and both margins 

taper to a distinct pointed apex. This differs significantly 

from the condition in the woody bamboos. The Olyreae 

also lack a marked asymmetry in the midrib outline and yet 

are widely considered to belong to the Bambusoideae; 

therefore, although the Phareae deviate from the subfamily 

definition with regard to this feature, little emphasis should 

be accorded this difference. In fact, this asymmetric tendency is only clearly applicable to the woody core group of 

the subfamily, and is rarely noted in non-woody genera. 

The midrib of the Phareae is in the form of a prominent 

keel with a complex vasculature (Figures 3a; 7a,d). This is 

characteristic of all the bambusoid grasses and strongly 

suggests affinities with this subfamily. The pharoid keel 

structure differs from the Bambuseae, however, in being 

symmetrical and semicircular and in lacking an elaborate 

system of sclerenchyma in which the vascular bundles are 

embedded. The pharoid keel projects abaxially (upwards), 

not adaxially as in the Olyreae, but it must be realized that 

it is functionally adaxially located due to the 180" twisting 

of the pseudopetiole, which results in the inversion of the 

blade. Thus, both pharoid and olyroid leaves effectively 

have adaxially projecting midribs, an unusual condition in 

the Poaceae. The advantage, if any, of this upward-facing 

central support of the blade in both of these groups of 

umbrophilic grasses is not clear, but it is interesting to note 

that selection has produced an apparent convergence in this 

evolutionarily somewhat distant pair of grass groups. 

The usually prominent transverse veins in Leptaspis, Pharus, and Scrotochloa conform to the condition in the subfamLEAF ANATOMY IN TRANSVERSE SECTION.-For purposes 

ily. These veins occur in many other grasses, however, 

particularly those from shaded forest habitats as in Zeugites 

of the Centotheceae (Camus, 1945), and perhaps they reflect a common ecological adaptation without phylogenetic 

significance. 

The double vascular bundle sheaths of the Phareae (Metcalfe, 1960; Renvoize, 1985; Figures 3b; 7c,e) are typically 

bambusoid. Of particular interest is the multi-layered inner 

sheath of small, uniformly thickened cells, a condition 

known only in the Bambusoideae. This feature, then, 

strongly links the two groups; all other subfamilies have but 

a single inner sheath of cells with endodermal-like thickenings. 

The arm and fusoid cells of both Leptaspis and Scrotochloa, 

along with Pharus, are strictly bambusoid features which 

indicate close relationships. Again, these structures in the 

Phareae diverge considerably from the typical condition in 

the Bambusoideae. The arm cell wall invaginations are 

poorly developed and are best observed in the palisade-like 

abaxial chlorenchyma (Figure 7c). This tendency again reflects the torsion of the leaf blade in the pharoids; the 

abaxial side of the leaf is functionally adaxial (upwardfacing), hence the palisade-like nature of the arm cells. Arm 

cells are usually best developed in the adaxial chlorenchyma 

in typical bambusoid grasses. The fusoid cells of the Phareae 

are interesting in that they do not appear to collapse into 

narrow plate-like structures with narrow lumina as they do 

in the other bambusoid grasses. Instead, even at maturity, 

they remain large, inflated, transversely elongated, and 

bladder-like, with exceptionally thin walls (Page, 1947; Rao 

and Naidu, 1981). In transverse sections, the fusoid cells 

are tightly packed along either side of each vascular bundle 

and extend halfway to the adjacent vascular bundle (Figure 

7e). Fusoid cavities are, therefore, not observed in leaf 

sections of the Phareae; the actual cells are always sectioned. 

This feature can clearly be seen in some epidermal preparations, particularly in macerations in which all of the mesophyll tissue is not cleanly removed. 

LEAF BLADE EPIDERMAL ANATOMY.-The anatomical 

features of the leaf blade in transverse section thus show 

that the Phareae closely resemble the bamboo core group 

or Bambuseae. This clear indication conflicts with the epidermal evidence, however, as the pharoid epidermis is 

unique in the Poaceae and differs substantially from the 

typical bambusoid condition. In fact, pharoid epidermal 

characteristics give little indication of even graminoid affinities and remain the major reason why there is still disagreement among agrostologists as to the taxonomic placement of the group. 

The intercostal zones of both epidermides of the Phareae 

are occupied by two distinct types of cells: normal intercostal 

long cells and groups of fibrous bands. The normal type of 

long cell is typically bambusoid, with thickened, very sinuous anticlinal walls. The presence of these striking fibrous 

bands (Metcalfe, 1960; Renvoize, 1985; Figures 3, 8), each 
FIGURE ’i.-Leafari;ituniy of the pcnus Pharus as seen in transverse sections; 

the ad;ixi;il (dowi~w;rrd-facing) sul-face fa(-cs upwards in these views: a-c, P. 

lappulaceus; a, outline of midrib showing complex vax-ulature (X 66); b, 

tapering srlerencliynia cap of the leaf inai-gin arid tiarrow lateral fusoid 

c-ells; note the absciire of interc-ostal fibrous bands on the adaxial surface, 

and their paucity 011 the abaxial srrrfacc (X 165); c, detail of first-ordetv;isculal- I)uiitllc with nicstome slieath consisting of several layers as well as 

fusoid and ai-111 c ell structure; iibitxial long cells quitc bullifor-

d-f, 1’. ~QW$~~U.T subsp. elongatus; d, outline of keel (X 106); e

region with fimid cclls and lirs- and third-ordrr vascular 

abuntlmicr of. intei-costal fibrous bands (arrows) on both sur

f, dclail of first-oder vascukir bundlc, fusoid crlls and chl

264). 1’. lappulaceus from Sudcrstrom 1805, Puerto Kico and 

subsp. elongalus from (;alderon and Dressler 2152. Panama. 
NUMBER 65 21 

of which is composed of a file of short cells positioned 

between a pair of fibers, is of extreme taxonomic importance, and their phylogenetic significance is undoubtedly 

great. These intercalating fibers, or fiber-like tracheids (Rao 

and Naidu, 1981) are unique and have not been reported 

in any other representative of the Poaceae, although the 

occurrence of leaf epidermal tracheids in other families 

(e.g., Theophrastaceae) is well documented in the literature. 

The possession of this unique feature tempts one to postulate that the pharoid grasses are not closely allied to any 

present day grass taxon, but the evidence of the leaf in cross 

section strongly suggests bambusoid affinities and too much 

significance should not be attached to one single outstanding characteristic. 

Perhaps correlated with the prominence of the intercostal 

fibrous bands, bulliform cells are absent from the epidermides of Leptaspis and Scrotochloa. In the species of Pharus 

in which the adaxial epidermis lacks these bands, however, 

the intercostal long cells farthest from the veins are somewhat larger than those closer to the veins and could be 

interpreted as poorly developed bulliform cells (Renvoize, 

1985; Figure 7b-c). Bulliform cells are common in the 

woody core group of the subfamily. 

The stomata1 subsidiary cells of Leftaspas, Scrotochloa, and 

Pharus are dome-shaped (Figure 3j) and conform to the 

bambusoid type. This subsidiary cell shape is not, however, 

exclusive to the Bambusoideae, being found also in the 

Panicoideae and Arundinoideae (Renvoize, 198 l), and consequently no great importance should be attached to this 

character state. 

Though common in the woody bamboo core group, 

minute, cutinized, epidermal papillae are poorly developed 

or totally absent in the pharoid grasses as they are in other 

peripheral bambusoids such as Anomochloa (Anomochloeae), 

Streptochaeta (Streptochaeteae), and Streptogyna (Streptogyneae). The absence of papillae, therefore, does not imply 

that the Phareae cannot be classified with the Bambusoideae 

but, again, indicates a peripheral position for this anomalous 

group. 

Microhairs appear to be absent from the leaves of the 

Phareae, corroborating the observations of Metcalfe (1 960), 

Jacques-F&x (1 962), Palmer and Tucker (198 l), and Renvoize (1985). Thus, Pharus, Scrotochloa, and Leptaspis join 

Streptogyna and Puelia in being the only bambusoids without 

microhairs, structures that are often considered to be universally present in non-festucoid grass genera Uohnston and 

Watson, 1977). This strengthens the case for removing 

these peripheral groups from the bambusoid nucleus. 

The silica bodies of the Phareae are quite different from 

the diagnostic bamboo type. In the pharoids these bodies 

are horizontally elongated and dumbbell-shaped, an exceptional configuration in the Bambusoideae. Pharoid silica 

bodies are closely associated with the unique epidermal 

fibrous bands, and thus the shape of these structures may 

be largely determined by their close association with these 

fibers. 

Based on epidermal structure, it is not possible to accommodate this tribe within the core of the bamboo subfamily, 

but based on leaf blade cross-sectional anatomy, the Phareae 

undoubtedly belong with this group rather than with any 

of the other subfamilies. If a broad view is taken of the 

circumscription of the Bambusoideae, then the Phareae can 

be accommodated together with the other herbaceous bamboo tribes and the Oryzeae outside the bambusoid core yet 

within a wider concept of the subfamily. The Phareae, then, 

constitute a separate tribe within the Bambusoideae sensu 

lato with diagnostic leaf blade anaiomical characters as listed 

below. 

Midrib symmetrical, keels semi-circular, abaxially projecting; vasculature complex. 

Inner bundle sheath multiple-layered around the primary 

vascular bundles; cells small, uniformly thickened. 

Arm cells invaginations poorly developed but most evident 

on the adaxial side of abaxially located mesophyll cells. 

Fusoid cells prominent; do not appear to collapse at maturity. 

Bulliform cells absent on the abaxial surface; poorly developed or absent on the adaxial surface. 

Intercostal epidermal fibers common in both adaxial and 

abaxial epidermides in both costal and intercostal zones, 

except for certain species of Pharus, which lack adaxial 

intercostal fibers; always in pairs enclosing a file of short or 

modified long cells. A unique feature of this group. 

Stomata more common on adaxial epidermal surface; 

subsidiary cells more or less dome-shaped. 

Papillae absent on both surfaces. 

Microhairs appear to be absent. 

Silica bodies horizontally elongated; round, oblong, rectangular, or most characteristically saddle-shaped. 

RELATIONSHIPS OF THE STREPTOGYNEAE TO THE 

BAMBUSOIDEAE 

Streptogyna has been variously classified by different authors. Early agrostologists noted the similarity of its spikelets 

to those of the pooid grasses, and thus placed the genus in 

the Festuceae (Kunth, 1835, as Festucaceae; Bentham, 

1881). This disposition was long accepted, and as late as 

1954 Pilger placed Streptogyna in this tribe, albeit in its own 

subtribe, the Streptogyninae. The anatomical studies of 

Metcalfe (1 956, 1960) gave preliminary evidence that Streptogyna might be close to the bambusoids and led other 

workers to modify their placement of the group, JacquesFelix (1962) putting the genus in its own “Serie” (corresponding roughly to a subfamily), and Tateoka (1 958a) 

grouping it with the pharoids. From this diverse classifactory history it is obvious that the taxonomic placement of 

Streptogyna has caused considerable difficulty in the past, 
22 SMITHSONIAN CONTRIBUTIONS TO BOTANY 
NUMBER 65 23 

but the genus is now generally placed in its own tribe within 

the Bambusoideae (Calderon and Soderstrom, 1980). 

M~RPH~L~cY .-At first glance, the narrow-leaved Streptogyna species appear to be quite unlike any bamboo. Similarities between the two groups do exist, however. Both 

groups have pseudopetiolate, tessellate leaf blades with an 

outer ligule, features otherwise rare in the Poaceae, and 

there is also agreement in such technical features as number 

of lodicules (three in each group) and basic chromosome 

number (n = 12; Hunziker, Wulff, and Soderstrom, 1982). 

The partial embryo structural formula given by JacquesFelix (1 962) is similar to that of the woody bamboos. Only 

in the apparent lack of a transitional first seedling leaf, at 

least in S. americana (Soderstrom, 1981), does the genus 

depart significantly from the usual bambusoid type. 

The outline in transverse section of the leaf blade of Streptogyna is not asymmetrical, as in the woody core group of 

the subfamily. This is particularly evident in that part of 

the lamina immediately adjacent to the midrib and the keel 

itself. As noted, this symmetrical nature of the two halves 

of the lamina also occurs in the Phareae and other herbaceous bamboos, which may all be included in the Bambusoideae in its broadest sense. The copious sclerenchyma 

associated with the median abaxial vascular bundle is a 

typical bambusoid characteristic (Metcalfe, 1956), and some 

of the minor bundles are actually embedded in this sclerenchyma tissue, a condition also illustrated by Jacques-Felix 

(1962). The adaxially located midrib bundles of both Streptogyna species are also embedded in fibrous tissue and 

Metcalfe (1 956) considers the vasculature of the midrib of 

the genus to resemble that of the true bamboos. 

The outer vascular bundle sheath is composed of relatively large, thin-walled cells that lack chloroplasts, and the 

multi-layered inner bundle sheath, with small cells having 

uniform wall thickenings (Figure 6b,f), are features confined to the Banibusoideae and in this respect Streptogyna 

confornis to the classical bambusoid condition. 

The mesophyll of Streptogyna is bambusoid in the presence of fusoid cavities on either side of each vascular bundle 

and in S. crinita small arm-like extensions are present in the 

chlorenchynia. Fusoid cells and arm cells are confined to 

the Banibusoideae and it was on the basis of this observation 

that Metcalfe (1 956) suggested affinities between StreptoANATOMY OF LEAF BLADE IN TRANSVERSE SECTION.- 

gyna and the bamboos. The leaf-blade anatomy as seen in 

transverse section, therefore, diverges very little from the 

bambusoid condition and confirms the assignment of the 

Streptogyneae to the Bambusoideae. 

LEAF BLADE EPIDERMAL ANATOMY .-The intercostal 

long cells of the specimens of Streptogyna examined (Figure 

6c,d) are unusual in not having markedly sinuous walls; in 

fact, the exceptionally long, tapering, fiber-like central long 

cells found on the abaxial epidermis of S. americana are 

hardly bamboo-like. More study of this feature is required, 

as Jacques-Felix (1 962) and Renvoize (1 985) illustrate and 

describe the long cells of S. crinita as moderately sinuous 

and Metcalfe (1 960) describes them as coarsely sinuous. 

The lack of microhairs and wrell-developed papillae in the 

genus is most unusual in the subfamily, and is paralleled 

only by their absence in the Phareae and Puelia. The 

vertically orientated silica bodies somewhat resemble the 

banibusoid type but they are not as well-developed as they 

are in most bambusoid tribes. Fan-shaped, well-developed, 

typically bambusoid clusters of bulliform cells are present 

on the adaxial surface of the blade. In summary, Streptogyna 

has many cross-sectional and several epidermal features that 

indicate banibusoid affinities, and retention of this tribe in 

the Banibusoideae appears justified on present evidence if 

the concept of the subfamily is broadened to include bamboo-like grasses that cannot be accommodated in the woody 

core of the group. 

The Streptogyneae constitutes a small but distinct tribe 

within the Banibusoideae and has the following leaf anatomical characteristics. 

Midrib symmetrical, abaxially projecting; keel triangular, 

with complex vasculature; vascular bundles at least partially 

embedded in sclerenchymatous tissue. 

Inner bundle sheath multiple-layered around the firstorder vascular bundles; cells small, uniformly thickened. 

Arm cells invaginations poorly to moderately well-developed. 

Fusoid cells well-developed across the width of the leaf 

blade. 

Bullijorm cells well-developed adaxially, in fan-shaped 

groups of 4 or 5. 

Epidermal long cells central files of intercostal zones with 

exceptionally long, tapered, fiber-like cells. Long cells with 

straight to sinuous anticlinal walls. 

FIGERE 8.-Abaxial (upward-facing) epidermal structure of the genus 

Pharus as seen in surface view; note prominent intercostal fibrous bands, 

each composed on two files of elongate, tapering fibers that enclose a row 

of short cells: a and 6, P. lappulaceus; a, intercostal fibrous bands, long cells 

and infrequent stomata along a costal zone (center) (X 135): 6, costal zone 

with files of fibers and dumbbell-shaped silica bodies, flanked on each side 

by a row of stomates. The normal intercostal long cells have sinuous walls 

(X 220); c and d, P. parvifolius subsp. elongatus; c, arrangement of costal 

(upper and lower) and intercostal zones, the latter with fibrous hands (X 

85); d, intercostal zone showing tapering ends of fibrous bands (X 135); e 

andf, P. lat2folius; e, costal (upper) and intercostal zones (X 85); f, detail of 

tapering ends of epidermal fibers, interference contrast (X 220); g and h, 

P. uirescens; g, general appearance of epidermis showing two dark, narrow, 

costal zones (X 55); h, detailed structure of intercostal epidermal fibers and 

associated silica cells, interference contrast (X 220). P. lappulaceus from 

‘Jenturi 7895, Argentina; P. paruifolaus subsp. elongatus from Calderon and 

Dressler 2152, Panama; P. latifolius from Soderstrom and Sucre 1886, Brazil; 

and P. virescens from Irwin et a/. 55044, Surinam. 
24 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Stomata dome-shaped; not overarched by papillae. 

Papillae poorly developed or absent on both surfaces. 

Microhairs absent. 

A final decision on the phylogenetic classification of the 

Phareae and the Streptogyneae will require an evaluation 

of all the relevant anatomical characters in combination in 

all of the tribes of herbaceous bamboos. These anatomical 

criteria should also be considered in conjunction with other 

proven and conservative taxonomic characters such as seedlings (Soderstrom, 1981), embryos (Reeder, 1962), and 

cytology (Hunziker, Wulff, and Soderstrom, 1982). 
List of Taxa 

ANOMOCHLOEAE C.E. Hubbard in Hutchinson 

Anomochloa Brongniart 

Leptaspis R. Brown 

A. niarantoidea Brongniart 

L. angustifolia Summerhayes and Hubbard 

L. banksii R. Brown 

L. cochleata Thtvaites 

L. comoroensis A. Camus 

L. conchifera Hackel 

L. manillensis Steudel 

L. urceolata (Roxburgh) R. Brown in Bennett 

L. 7eylanica Nees ex Steudel 

Maclurolyrd tecta Calderon and Soderstrom 

Olyra Linnaeus 

Orthoclada Palisot de Beauvois 

PHAREAE Stapf in Thiselton-Dyer 

Pharus P. Browme 

P. lappulaceus Aublet 

P. latifolius Linnaeus 

P. parvifolius Nash 

P. parvifolius subsp. elongatus Judziewicz 

P. urceolatus Roxburgh 

P. virescens Doell in Martius 

Puelia Franchet 

Scrotochloa Judziewicz 

S. tararaensis (P. Jansen) Jud7ieiricz 

S. urceolata (Roxburgh) Jud~iewici 

Setaria paniculifera (Steudel) Fournier 

STREPTOCHAETEAE C.. Hubbard in Hutchinson 

STREPTOGYNEAE C.E. Hubbard ex Calderon and Soderstrom 

Streptochaeta Schrader ex Nees 

Streptogyna Palisot de Beauvois 

S. americana C.E. Hubbard 

S. crinita Palisot de Beauvois 

S. gerontogaea J.D. Hooker in Trimen 

Zeugites P. Browne 

2.5 
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