SMITHSONIAN CONTRIBUTIONS TO BOTANY NUMBER 90 

Seed Micromorphology of 

Neotropical Begonias 

A. de Lange 

and E Bournan 

Smithsonian Institution Press 

Washington, D.C. 

1999 
ABSTRACT 

Lange, A. de, and F. Bouman. Seed Micromorphology of Neotropical Begonias. Smithsonian 

Contributions to Botany, number 90,49 pages, 1 figure, 21 plates, 1999.-The seeds of about 

235 Neotropical Begonia species, representing almost all recognized American Begonia sections, were studied using scanning electron microscopy. The seeds show an appreciable diversity in size, shape, and micromorphology, which is helpful in the delimitation of sections and 

sometimes also of species. Mean seed length varies from 235pm in Begoniafilipes to 1450 pm 

in B. fiuticosa; most seeds have a length between 300 pm and 600 pm. The shape of the seeds 

varies from almost globular to narrowly elliptic, and the length to width ratio ranges from 1.2 

in B. hexandra to 8.1 in B. fruticosa. Further differences exist in the shape of the testal cells, 

the undulation of the anticlinal walls, the bulging of the outer periclinal walls, and the pattern 

and roughness of the cuticle. 

Five of the 15 mainly Brazilian, five of the 12 Andean and Guianan, and one of the eight 

middle American sections have a seed structure that is characteristic at the sectional level. All 

these sections have a relatively restricted geographical distribution, and they may differ in 

growth form or habitat. Most species of the other sections, including the larger and more 

widely distributed sections Begonia, Gireoudia, and Knesebeckia, have seeds conforming to 

the ordinary seed type. 

In a number of the sections, the structural differences of the seeds are nicely correlated with 

differences in growth form and/or in means of dispersal. In contrast to the African begonias, 

the great majority of the Neotropical begonias have anemoballistic dispersal. Seeds may be 

adapted to wind dispersal by extended micropylar and/or chalaza1 ends with inflated, air-filled 

cells, such as in the Brazilian sections Solananthera, Trendelenburgia, and Enita and in the 

Andean section Rossmannia, or by a more pronounced surface with deep, collapsed testal cells, 

such as in sections Gobenia and Scheidweileria. Zooballistic dispersal by passing animals is 

supposed to be present in section Casparya. The seeds of sections Casparya and Trachelocarpus have very pronounced cuticular patterns and may be secondarily dispersed by rain wash or 

by adhering to animals. 

No distinct indications for an intercontinental relationship between Neotropical, African, and 

Asiatic sections could be established. 

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

recorded in the Institution's annual report, Annals of the Smithsonian Institution. SERIES COVER 

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

Library of Congress Cataloging-in-Publication Data 

De Lange, A. (Anton) 

Seed micromorphology of neotropical begonias / A. de Lange and F. Bouman 

Includes bibliographical references. 

1. Begonias-Seeds-Morphology. 2. Scanning electron microscopy. 

I. Bouman, F. 11. Title. 111. Series. 

QKl.S2747 no. 90 

[QK495 .B4] 

580 s-dc21 

[583'.6271467] 

p. cm. - (Smithsonian contributions to botany ; no. 90) 

99-30195 

CIP 

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

National Standard for Permanence of Paper for Printed Library Materials 239.48-1 984. 
Contents 

Page 

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

Acknowledgments .................................................. 2 

Material and Methods ............................................... 2 

Description of Seeds of Neotropical Begonias ................................ 3 

1 . Sections Mainly Confined to Brazil and Some Adjacent Countries ........... 3 

1.1. Section Trachelocarpus A . DC .................................... 3 

1.2. Section Solananthera A . DC ..................................... 3 

1.3. Section Trendelenburgia (Klotzsch) A . DC .......................... 4 

1.4. Section Scheihveileria (Klotzsch) A . DC ........................... 4 

1.5. Section Ewaldia A . DC ......................................... 5 

1.6. Section Enita Brade ............................................ 5 

1.7. Section Pritzelia (Klotzsch) A . DC ................................ 6 

1.8. Section Philippomartia A . DC .................................... 7 

1.9. Sections Steineria (Klotzsch) A . DC . and Bradea Toledo .............. 7 

1.10. Section Tetrachia Brade ........................................ 8 

1.11. Section Gaerdtia (Klotzsch) A . DC ................................ 8 

1.12. Section Latistigma A . DC ....................................... 8 

1.13. Section Pereira Brade .......................................... 9 

2 . Sections Mainly Confined to the Andean and Guianan Regions .............. 9 

2.1. Section Casparya (Klotzsch) A . DC ............................... 9 

Begonia urticae Group ........................................ 9 

Begonia ferruginea Group ..................................... 10 

Begonia trispathulata Group ................................... 10 

Begonia pectennervia Group ................................... 11 

Begonia antioguensis ......................................... 11 

Begoniahexandra ........................................... 11 

Begonia diversistipulata Group ................................. 12 

UngroupedSpecies .......................................... 12 

2.2. Section Rossmannia (Klotzsch) A . DC ............................. 12 

2.3. Section Hydristyles A . DC ....................................... 12 

2.4. Section Warburgina 0 . Kuntze ................................... 13 

2.5. Section Gobenia A . DC ......................................... 13 

2.6. Section Meionanthera A . DC ..................................... 14 

2.7. Sections Lepsia (Klotzsch) A . DC . and Tittelbachia (Klotzsch) A . DC .... 14 

2.8. Section Eupetalum (Lindley ex Klotzsch) A . DC., Including the Former 

Section Huszia (Klotzsch) A . DC ................................ 14 

2.9. Section Apteron C . DC .......................................... 15 

2.10. Section Barya (Klotzsch) A . DC .................................. 15 

3 . Sections Occurring both in Brazilian and in Andean Regions ................ 16 

3.1. Section Pilderia A . DC ......................................... 16 

3.2. Section Australes Smith & Schubert ............................... 16 

Regions ........................................................ 16 

4.1. Section Urniformia Houghton ex Ziesenhenne ....................... 17 

4.2. Section Gireoudia (Klotzsch) A . DC ............................... 17 

4.3. Section Hexaptera Ziesenhenne .................................. 17 

4.4. Section Dissepbegonia Ziesenhenne ............................... 18 

4 . Sections Mainly Confined to the Central American, Mexican, and Caribbean 

... 

111 
iv SMITHSONIAN CONTRIBUTIONS TO BOTANY 

4.5. Section Podandra A . DC ........................................ 18 

4.6. Section Weilbachia (Klotzsch & Oersted) A . DC ..................... 18 

5 . Section Mainly Occurring in both Andean and Middle American Regions ..... 19 

5.1. Section Ruizopavonia A . DC ..................................... 19 

6 . Sections with a Wide Neotropical Distribution ........................... 20 

6.1. Section Doratometra (Klotzsch) A . DC ............................. 20 

6.2. Section Begonia Baranov & Barkley .............................. 20 

BegoniaobliquaGroup ....................................... 21 

Begonia cucullata-Begoniafischen Group ....................... 21 

Ungrouped Species .......................................... 22 

Section Knesebeckia (Klotzsch) A . DC ............................. 22 

Section Donaldia (Klotzsch) A . DC ............................... 23 

Discussion ............................................................ 23 

SeedMorphology .................................................... 23 

Delimitation and Interrelationships of Neotropical Sections ................... 24 

Possible Intercontinental Relationships .................................... 25 

Seed Structure in Relation to Dispersal and Growth Form ..................... 26 

Literature Cited ........................................................ 28 

6.3. 

6.4. 
Seed Micromorphology of 

Neotropical Begonias 

A. de Lange 

and I;: Bouman 

Introduction 7 hi I urn mi cropyl e 

The genus Begonia L. represents one of the larger genera of 

flowering plants and has a complicated taxonomic history. Generic concepts in the family Begoniaceae have changed much; 

about 50 genus names have been put into synonymy with Begonia. According to current opinions, the family comprises 

only the genera Begonia, Hillebrandia, and Symbegonia, although Symbegonia was classed under Begonia by Mabberley 

(1989). Hillebrandia sandwicensis Oliver, of the monotypic 

genus Hillebrandia, is endemic to Hawaii. 

According to Smith et al. (1 986) and Golding (1 992), Begonia comprises almost 1400 species arranged into 78 sections 

(Baranov and Barkley, 1974), some of which are dubious or 

under discussion. Each section is restricted to a single continent 

except sections Begonia and Knesebeckia, which have an 

American-Asian distribution. 

The seeds of Begoniaceae are characterized at the family level by the presence of a transverse ring of so-called collar cells. 

These cells are usually elongated and border the micropylar-hilar part of the seed. During germination, this part separates 

along preformed rupture lines and is lifted off like a seed lid or 

operculum (Figure l), and the walls between the collar cells 

split to clear the way for the emerging seedling (Bouman and 

de Lange, 1983). The seeds of begonias show an appreciable 

diversity in size, shape, and micromorphology. The most common “ordinary” Begonia seeds mostly measure between 300 

pm and 600 pm long. As far as is known, the extremes are 

found among the African begonias: the smallest seeds are recorded from B. iucunda Irmscher, with a mean seed length of 

A. de Lange and F. Bouman, Hugo de Vries-Laboratory, University of 

Amsterdam, Kruislaan 318, 1098 SM Amsterdam, the Netherlands. 

Review Chairperson: Warren L. Wagner, Department of Botany, 

National Museum of Natural History, Smithsonian Institution, Washington, D.C., 20560-0166. 

Reviewers: K. Burt-Utley, Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana: D.C. Wasshausen, 

Department of Botany, Smithsonian Institution, Washington, D. C. 

t 

opercul urn 

col I ar cel I 

other testa cel I 

FIGURE. 1 .-Diagram of a Begonia seed with various parts labelled. 

220 pm, and the largest are from B. ebolowensis Engler, with a 

mean length of 2240 pm (de Lange and Bouman, 1992). 

The African begonias have received considerable attention 

by De Wilde and colleagues during the last 15 years (de Wilde, 

1985, 1992). Using a multidisciplinary approach (including 

karyology, pollen morphology, stigma morphology (Panda and 

de Wilde, 1995), placentation, seed morphology, and leaf anatomy (Sosef, 1994)), sections have been revised and intersectional relations have become clearer. A comparative scanningelectron-microscopy (SEM) study proved seed micromorphology to be a very useful additional character set, especially at 

the sectional level (de Lange and Bouman, 1992). The African 

begonias showed a considerable diversity in seed size and 

1 
2 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

structure. Moreover, differences in seed structure appeared to 

be distinctly related to the means of seed dispersal. In contrast 

to the general opinion that wind dispersal is the predominant 

means of dispersal in Begonia (van der Pijl, 1972), the seeds of 

the majority of the African Begonia species are dispersed by alternative ways. Animals may eat the fleshy, often colored 

fruits; seeds also may be dispersed by mud on the legs of passing animals or by rain wash (de Lange and Bouman, 1992). 

The taxonomy of the Neotropical begonias is far from settled. During his long botanical career, Lyman B. Smith, in cooperation with Bernice G. Schubert and later Dieter C. 

Wasshausen, published a series of contributions to regional or 

national floras. Taxonomic revisions at the sectional level, 

however, unfortunately are lacking, with the exception of the 

study by Burt-Utley (1 985) on the Central American and Mexican species of section Gireoudia. Because of the lack of a recent, updated revision of the Neotropical Begonia sections we 

have mainly followed the publication of Baranov and Barkley 

(1974) for sectional classifications and for the determination of 

their type species. It is important, however, to realize that their 

work was in large part based on published descriptions and did 

not involve critical examination of many species. A number of 

new sections described later have been added. For the sectional 

affiliation of species, we have used the publication of Barkley 

and Golding (1974) supplemented with data from later publications on newly described species. 

In the Neotropics, about 600 Begonia species are recognized. 

According to Baranov and Barkley (1 974), these are arranged 

in 47 sections; however, four of these sections, Auriformia, 

Zrmscheria, Quadriperigonia, and Saueria, have since been 

eliminated due to synonymy. The monotypic section Dasystyles is of uncertain origin and is based on cultivated specimens. Twenty of the sections dealt with in the present paper 

have held generic status in the past (e.g., Casparya, Gireoudia, 

Huszia, Pritzelia, Scheidweileria). 

For convenience, we have arranged the sections discussed 

herein according to six areas of geographical distribution. Thirty-five sections have a restricted geographical distribution, 

with the species of 15 sections confined mainly to Brazil and 

some adjacent countries, 12 sections confined to the Andean 

and Guianan regions, and eight sections confined to the Central 

American, Mexican, and Caribbean regions. The species of 

seven sections have a wider distribution: two sections occur in 

both Brazilian and Andean regions, one section occurs in both 

Andean and Central American regions, and four sections have 

a more extended Neotropical distribution. 

The possibility of a sectional classification within the genus 

Begonia has been questioned repeatedly. Smith and Schubert 

(1 946) discussed the use of placental form as the basis for division into sections but in subsequent publications ignored sections altogether. In her description of the begonias of Madagascar, Keraudren-Aymonin ( 1983) also renounced classifying 

species into previously recognized sections. The studies on African begonias, however, clearly demonstrated the sensibleness 

and usefulness of a sectional division. Sosef (1994: 11) made a 

strong plea to taxonomists always to denote the section to 

which any given species belongs. 

Our study aims at a better insight into the diversity of seed 

structure of Neotropical begonias and the adaptive characters 

for dispersal. Moreover, it may provide arguments for sectional 

delimitation. 

ACKNOWLEDGMENTS.-The authors are much indebted to J. 

Doorenbos (Department of Horticulture, Wageningen, the 

Netherlands), who sparked our enthusiasm for Neotropical begonias and who supplied us with a number of seed samples 

from his former collection of cultivated species. Moreover, he 

critically reviewed the manuscript and especially added valuable data to the descriptions and relationships of the sections. 

We thank the late Lyman B. Smith (National Museum of Natural History (NMNH), Smithsonian Institution, Washington, 

D.C.) for his indications of taxonomic problems on sectional 

delimitation. Dieter Wasshausen (NMNH) is gratefully acknowledged for his interest and hospitality during the first author’s visit to the United States National Herbarium. 

We thank J.J.F.E. de Wilde and M.S.M. Sosef of the Department of Plant Taxonomy, Wageningen Agricultural University, 

for their stimulating discussions on Begonia systematics. The 

directors and curators of herbaria cited in the text are gratefully 

acknowledged for providing facilities to study their collections 

or for loan of material. 

M.G. Bouman and N. Devente assisted in the typing of the 

manuscript, F.D. Boesewinkel and J. Dahmen processed several thousands of SEM photographs, and W. Takkenberg provided technical assistance with SEM (Hugo de Vries-Laboratory, 

Amsterdam). The Netherlands Organization for Scientific Research financed the visit of the first author to the herbaria of 

Washington, D.C., and St. Louis, Missouri. 

MATERIAL AND METHODS.-Most of the seed material was 

collected by visits to and/or by loan from the following herbaria: AAU, AMD, B, COL, CR, G, GENT, K, L, MO, P, PDA, 

PRE, RB, SP, U, US, and WAG. Moreover, seeds were received from the American Begonia Society Seed Fund (ABS), 

the former collection of cultivated begonias at the Department 

of Horticulture, Wageningen (WAG), and from the collections 

of L. Goldsmith (University of Vermont (VT)) and R. Ziesenhenne (Santa Barbara, California). Of the seeds received from 

Ziesenhenne, vouchers are present in his personal herbarium. 

No vouchers are available for the seeds obtained from ABS. 

For the smaller sections, seeds of all available species were 

collected and studied. For the larger sections, seeds of a number of representative species were chosen. Mature seeds were 

sputter-coated with gold-palladium for 2 to 3 minutes and were 

observed using either a Cambridge Stereoscan MK 2a or an IS1 

DS-130. Dirty seeds were cleaned by soaking in water with a 

detergent and by subsequent ultrasonic vibration. 

Seed size was determined from SEM measurements of usually six seeds. The seed width was measured at the widest apparent point. All mentioned mean sizes are arithmetically determined. 
NUMBER 90 

Description of Seeds of Neotropical Begonias 

In the descriptions of Neotropical Begonia seeds, we emphasize those sections with a characteristic seed structure that 

sometimes can be related to special growth forms or to methods of seed dispersal. Sections with seeds conforming to the ordinary seed type are dealt with more briefly. Although variation in seed micromorphology between sections can provide 

taxonomic information, in view of the issue of correct identifications and the sometimes complicated nomenclature, detailed 

comparative studies are most valuable when done in close cooperation with taxonomists. 

The results are presented according to the main geographical 

distributions of the sections for reason of surveyability and are 

not intended to suggest evolutionary relationships. 

1. SECTIONS MAINLY CONFINED TO BRAZIL AND 

SOME ADJACENT COUNTRIES 

Of the 15 Brazilian or mainly Brazilian sections, five (Enita, 

Scheidweileria, Solananthera, Trachelocarpus, Trendelenburgia) share a unique seed structure that is characteristic at the 

sectional level. Seeds of the species within each of these sections can be distinctly discerned from those of all other sections. Of nine remaining sections, the seeds of all or most species have a more ordinary structure. No seeds were available 

from B. schlumbergerana Lemaire of the monotypic section 

Plurilobaria. This section is questionable because it is based 

on a dubious type species described from a cultivated specimen, probably related to section Ewaldia (Warburg, 1894). 

1.1. Section Trachelocarpus A. DC. 

PLATE 1 a-c, e, f 

This taxon was first described by Klotzsch as the genus Trachelanthus in 1855. C. Mueller (1857) changed the name to 

Trachelocarpus, and subsequently A. De Candolle (1 859) reduced its status to sectional level. The section now comprises 

six species, restricted to Brazil. The taxonomically correct section type (Doorenbos et al., 1998) is Begonia depauperata 

Schott (=B. rhizocarpa Fischer ex A. DC.). Seeds were not 

available for B. angraensis Brade, B. fulvo-setulosa Brade, or 

B. velloziana Walp. 

The species of the section are characterized by a rhizomatous 

habit and almost equal-sided lanceolate leaves. Moreover, the 

inflorescences are unisexual: the male ones are stalked cymes; 

the female ones are reduced to a single subsessile flower. The 

ovary and fruit have three narrow wings joining a beak-like 

elongation bearing tepals and styles with stigmas. All species 

are epiphytic, creeping herbs. 

TYPE SPECIES.-Begonia depauperata (Plate le). 

Seed Structure: Seeds ellipsoid to narrowly ellipsoid, 

750-830 pm in length, 305-330 pm in width, mean 800 pm x 

320 pm, 1ength:width ratio 2.5. Collar cells relatively short, 

175-280 pm in length, mean 205 pm, number in seed circumference about 14. Ratio of collar-cell length to seed length 

1 :4.0. Other testa cells polygonal, arranged in rows of about 10 

cells. Anticlinal walls straight to slightly curved. Testa cells 

shallow, with collapsed outer periclinal walls forming ridges 

parallel to anticlinal boundaries. Operculum obtusate, composed of many irregularly arranged small cells. 

Anticlinal boundaries straight or 

sometimes sunken. Cuticle with net-like structure of upright or 

folded-over pleats. Cuticular striae usually occurring only locally, especially on anticlinals or in patches on smaller apical 

cells of operculum. 

Specimen Examined: 

B. depauperata, BRAZIL: Campos Goer 140 (B). 

OTHER SPECIES OBSERVED (Plate la-c, f ).-Seed Structure 

and Micromorphology: Begonia herbacea Vellozo and B. 

lanceolata Vellozo (syn. B. attenuata A. DC.) have seed structures that resemble those of B. depauperata in general morphology and cuticular structure. Seeds of B. herbacea have a 

mean size of 850 pm x 370 pm. Seeds of B. herbacea var. ellipticifolia Irmscher are slightly longer, 855-935 pm (mean 

910 pm x 370 pm), have a 1ength:width ratio of 2.5, and the 

anticlinal boundaries of the collar and testa cells are much 

more distinctly sunken. The seeds of B. lanceolata have a mean 

size of 1030 pm x 410 pm. 

Specimens Examined: 

B. herbacea var. ellipticifolia, BRAZIL: Ule 4240 (B). 

B. herbacea var. herbacea, BRAZIL: Loefgren s. n. (B); LisedecB. lanceolata, BRAZIL: L.B. Smith & Pereira 15343 (US). 

Seed Micromorphology: 

ceales s.n. (B). 

1.2. Section Solananthera A. DC. 

PLATE ld,g,h 

The section Solananthera was established by A. De Candolle 

in 1859. It contains three species restricted to Brazil. The species are epiphytic, climbing subshrubs. The section is characterized by the presence of porate anthers and two-divided placentas, the lobes of which cling to each other. The seeds of the 

three species have been described in detail (de Lange and Bouman, 1986). 

TYPE SPECIES.-Begonia solananthera A. DC. (Plate Id). 

Seed Structure: Seeds narrowly elliptic to narrowly obovate, mostly straight, sometimes J- or C-shaped. Mean seed 

size 755 pm x 145 pm, 1ength:width ratio 5.2. Mean length of 

collar cells 250 pm, with collar-cell length : seed length ratio of 

3.0. Other testa cells elongated, anticlinal walls finely undulated. Outer cell walls convex. Operculum obtuse, funnel-like, 

with sunken hilum. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticular pattern consisting of long linear undulated striae. 

Specimen Examined 

B. solananthera, BRAZIL: cult., Dept. Horticulture (WAG). 

OTHER SPECIES OBSERVED (Plate lg,h).-Seed Structure 

and Micromorphology: Begonia radicans Vellozo and B. in- 
4 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

tegerrima Sprengel have seed structures that resemble those of 

B. solananthera in shape, general morphology, and cuticular 

pattern. Mean seed sizes are 1060 pm x 170 pm and 885 pm x 

155 pm, respectively, and the length :width ratios are 1 : 6.2 and 

1 : 5.7, respectively. The seeds of B. radicans also strongly resemble those of B. fruticosa of section Trendelenburgia. The 

periclinal walls of the testa cells are collapsed, with the exception of those at the chalaza of B. radicans. 

B. integerrima var. integerrima, BRAZIL: E. Pereira 606 (RB). 

B. radicans, BRAZIL: H. Luederwaldt s.n. (SP); A.P. Duarte 

Specimens Examined: 

3377 (RB). 

1.3. Section Trendelenburgia (Klotzsch) A. DC. 

PLATE 2a, f 

The taxon Trendelenburgia was first described by Klotzsch 

as a genus in 1855 on the basis of one of the early Begonia collections by Ludwig Riedel in 1839. A. De Candolle (1864) 

changed the status to sectional level. Most probably the section 

is monotypic, with B. fruticosa as the type species. 

The section is characterized by three-celled fruits with three 

equal-sized, very narrow wings and undivided placentas. The 

plants are slender-stemmed shrubs with a tendency to climb 

and with simple, pinnately veined leaves. Begoniafi-uticosa occurs in Argentina and southern Brazil. 

TYPE SPECIES.-Begonia fruticosa A. DC. (Plate 2a,f). 

Seed Structure: Seeds narrowly ellipsoid, extended micropylar and chalaza1 ends composed of bulging, air-filled cells. 

Testa cells covering central, embryo-containing part collapsed. 

One or both sides of seeds may be curved, rendering seeds Jor slightly S-shaped. Seed length 1310-1540 pm, width 

160-200 pm, mean 1450 pm x 180 pm, 1ength:width ratio 8.1 

(slenderest seeds ever encountered in Begonia). Seeds of above 

described collection (Martins 8380) the biggest. Seeds of collections Herb. Brasil 171 7, Kummrow 1636, a!.d Herb. Brad 

850 with mean lengths of 1060 pm, 1005 pm, and 965 pm, respectively, and 1ength:width ratios of 7.3, 5.4, and 6.3, respectively. Ratio of embryo-containing part to seed length 1 :2.4. 

Collar cells strongly elongate, 275-380 pm in length, mean 

325 pm, number in seed circumference about 10. Collar-cell 

length to seed length ratio 1 :4.5. Longitudinal anticlinal walls 

of collar mostly undulated along entire length. Other testa cells 

of central part of seed also distinctly elongated and with undulated walls. Cells of operculum adjacent to collar elongated. 

Hilum sunken. 

Anticlinal boundaries of operculum and chalaza sunken, those of central part of seed somewhat 

less so. Cuticle smooth, locally with faint, striate ornamentation, cuticle of central part of seed reflecting underlying pits. 

Larger pits present at bases of anticlinal walls. 

B. fruticosa, BRAZIL: R. Kummrow I636 (MO); H.F. Martins 

Seed Micromorphology: 

Specimens Examined: 

8380 (US); H. Schenck, Herb. Brazil 850, 171 7 (B). 

1.4. Section Scheidweileriu (Klotzsch) A. DC. 

PLATE 2b-e,g, h 

The section Scheidweileria was described by Klotzsch as a 

genus in 1855. The section comprises six species, one of 

which, B. luxurians, is well known as a collector’s plant. They 

are shrubs or small trees with compound, palmately veined 

leaves containing cystoliths and with large inflorescences that 

are dichotomous at the bases. The female flowers are characterized by five tepals, stigmas as helical bands with three turns, 

and undivided placentas. No seeds were available for B. semidigitata Brade. 

Most species of the section are limited to Brazil, but B. 

parviflora Poeppig & Endler has a wider distribution, extending to southern Central America. 

TYPE SPECIES.-Begonia pentaphylla Walpers (Plate 2b,c). 

Seed Structure: Seeds ellipsoid to narrowly ellipsoid, 

600-680 pm in length, 220-300 pm in width, mean 640 pm x 

265 pm, 1ength:width ratio 2.4. Collar cells elongate, 180-280 

pm in length, mean 225 pm, number in seed circumference 

about 12. Ratio of collar-cell length to seed length 2.8. 

Longitudinal anticlinal walls of collar straight. Other testa 

cells polygonal, with straight anticlinal walls. Testa cells at 

chalaza with higher anticlinal walls and becoming deep due to 

collapse of outer periclinal walls. Chalaza usually flattened on 

one side, probably from contact with inner surface of fruit wall, 

resulting in cell crumpling. Border between collar and operculum abrupt. Operculum nipple-shaped, with collapsed cells. 

Anticlinal boundaries flat. Cuticular pattern variable, that of collar cells mainly linear, that of remaining testa cells with shorter linear, undulated, or short zigzag striae. Locally, patches with less pronounced, mainly linear 

pattern. 

Specimen Examined: 

B. pentaphylla, BRAZIL: B. and C. Maguire and J. Murca Pires 

44596 (US). 

OTHER SPECIES OBSERVED (Plate 2d,e,g,h).-The seeds of 

other species observed are characterized by a flattened chalaza 

with deep testa cells as described above for B. pentaphylla, but 

they show distinct differences in seed lengths. 

Seed Structure and Micromorphology: The seeds of B. 

parvijlora are 270-350 pm in length, 155-180 pm in width, 

with a mean of 3 15 pm x 170 pm, and have a length: width ratio of 1.9. They most resemble the ordinary type of begonia 

seed. 

The seeds of B. luxurians Scheidweiler and B. digitata Raddi 

are longer and closely resemble each other. Begonia Iuxurians 

seeds (Hoehne 2370) are 580-640 pm in length and 180-200 

pm in width, with a mean of 610 pm x 185 pm and a 

1ength:width ratio of 3.3. The collection de Burros 1139 has 

smaller seeds, with a mean of 485 pm x 195 pm. Begonia digitata seeds are 595-655 pm in length and 165-210 pm in width, 

with a mean of 625 pm x 185 pm and a length: width ratio of 

2.9. The operculum in B. digitata and B. luxurians is broadly 

Seed Micromorphology: 
NUMBER 90 5 

nipple-shaped, sometimes obtusate, and has a sunken hilum 

(Sellow s.n. and Martinelli C.S. 8045, respectively). 

The seeds of B. incisoserrata A. DC. vary appreciably in 

size, being 370-500 pm in length and 170-215 pm in width, 

with a mean of 425 pm x 185 pm and a length : width ratio of 

2.4. 

The species of the section have straight or slightly curved anticlinal walls except B. parvijlora, in which all specimens 10- 

cally have slightly undulated anticlinal walls in the collar and 

testa. The species have a cuticular pattern as described for B. 

pentaphylla. 

Specimens Examined: 

B. digitata var. digitata, BRAZIL: Martinelli & Maas 3271 (U); 

Sellow s.n. (P); L.B. Smith cs. 6691 (US). 

B. incisoserrata, BRAZIL: A.C. Brade 20096 (B); G. Hatschbach & R. Kummran 45532 (US). 

B. luxurians var. luxurians, BRAZIL: D. de Burros 1139 (B); 

F.C. Hoehne 2370 (B); G. Martinelli, Kautsky, & Leme 

8045 (US). 

B. parvifora, COLOMBIA: Ed. Andre K 284 (K); J. Cuatrecasas 

11311 (us); Kill@ 7837 (us). ECUADOR: Holguer Lug0 S 

1808 (MO). 

1.5. Section Ewaldia A. DC. 

PLATE 3a-d 

This taxon was described by Klotzsch (1 855) as a genus and 

was reduced to a section by A. De Candolle in 1864. It was 

maintained as such by subsequent monographers (Warburg, 

1894; Irmscher, 1925). The section comprises about 1 1 species. 

They resemble the species of section Scheidweileria in a number of characters, but they differ, among other characters, in the 

pinnate venation and in the shape and hairiness of the leaves. 

Except for the Venezuelan species B. boucheana (Klotzsch) A. 

DC., the species are limited to Brazil. 

TYPE SPECIES.-Begonia lobata Schott (Plate 3a). 

Seed Structure: Seeds ellipsoid to narrowly ellipsoid, 

565650 pm in length, 195-2 15 pm in width, mean 605-200 

pm, 1ength:width ratio 3.0. Seeds of collection Esteves C.S. 

CFCR 6028 differ in size and shape, with mean seed size of 

515 pm x 265 pm and 1ength:width ratio of 1.9. Collar cells 

elongate, 1 15-2 10 pm in length, mean 165 pm, number in seed 

circumference about 13. Ratio of collar-cell length to seed 

length 3.6. Testa cells adjacent to collar somewhat elongated, 

those at chalazal end more polygonal. Anticlinal walls straight. 

Chalaza usually flattened, but cells not crumpling. Operculum 

broadly nipple-shaped. 

Anticlinal boundaries flat. Cuticular pattern coarse, that of chalazal cells with short linear or 

short undulated striae. Locally, patches with less pronounced, 

denser pattern. 

B. lobata, BRAZIL: G.L. Esteves C.S. CFCR 6028 (SP); G. 

B. aff. lobata, BRAZIL: P.J.M. Maas C.S. 3318 (U). 

Seed Micromorphology: 

Specimens Examined: 

Hatschbach 30073 (US), 36564 (MO). 

OTHER SPECIES OBSERVED (Plate 3b-d).--Seed Structure 

and Micromorphology: The seeds of B. rigida Linden ex Regel, B. scharffii Hook.f., and B. tomentosa Schott resemble 

those of B. lobata in the coarse cuticular pattern and the 

straight anticlinal walls and boundaries. They differ, however, 

in a nipple-shaped operculum, smaller size, and the presence of 

a cuticular pattern with both short linear and short undulated to 

short zigzag striae. Mean seed sizes are 390 pm x 190 pm (B. 

rigida), 485 pm x 220 pm (B. scharfli), and 485 x 2 10 pm (B. 

tomentosa), with 1ength:width ratios of 2.1, 2.2, and 2.3, respectively. The seeds of section Ewaldia, especially those of B. 

lobata, resemble the seeds of section Scheidweileria in shape, 

in size, and in having a somewhat massive operculum. 

B. rigida, BRAZIL: ABS Seed Fund (1983). 

B. scharffii, BRAZIL: Palacios-Cuezzo 2930 (US). 

B. tomentosa var. tomentosa, BRAZIL: A.C. Brade 18572 (US). 

Specimens Examined: 

1.6. Section Enita Brade 

PLATE 3e, f-k 

The species now constituting section Enita have a rather 

complicated taxonomic history. Klotzsch (1 855) attributed the 

species then described, together with a number of species now 

mainly in section Pritzelia, to his genus Wageneria. A. De 

Candolle (1861) transferred this genus to Begonia section 

Wageneria. Warburg (1 894) merged Wageneria with the large 

section Pritzelia, and this opinion was shared by Irmscher 

(1 925). Brade (1 945) established Enita as a subsection and later raised it to sectional level (Brade, 1957). The correct name 

of the section should be Wageneria Klotzsch, with B. fagifolia 

hort. Petrop. ex Otto & Dietrich as type species (Doorenbos et 

al., 1998). The section comprises probably 10 species. The species of section Enita deviate from those of section Pritzelia by 

having stamens with filaments slightly united below and anthers usually much shorter than the filaments, and by having 

cylindrical seeds crowned with a group of larger cells at the 

chalaza. Moreover, they are climbing semishrubs with stems 

that often produce adventitious roots at the nodes and that have 

symmetrical or subsymmetrical, pinnately or palmately veined 

leaves. 

All species are limited to Brazil except B. glabra Aublet, 

which has a wider distribution, occurring in the West Indies 

and from Mexico to Colombia and Ecuador. 

TYPE SPECIES.-Begonia convolvulacea (Klotzsch) A. DC. 

(Plate 3e). 

Seed Structure: Seeds narrowly ellipsoid, micropylar and 

chalazal ends differing, 635-705 pm in length, 180-2 15 pm in 

width, mean 675 pm x 195 pm, length: width ratio 3.4. Collar 

cells elongate, 130-475 pm in length, mean 275 pm, number in 

seed circumference about 1 1. Ratio of collar-cell length to seed 

length 2.4. 

Longtitudinal anticlinal walls of collar and other testa cells 

usually straight, sometimes slightly undulated. Other testa cells 
6 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

also elongated. Chalaza1 end of seed flattened and with cells 

with higher anticlinal walls. These cells may become deep 

from collapse of outer periclinal walls or somewhat inflated 

from bulging of outer walls. Operculum obtusate, with sunken 

hilum. 

Anticlinal boundaries usually flat 

but sunken at boundary of collar and operculum and at chalaza. 

Cuticular pattern weakly developed, with linear or short linear 

striae, more distinct at operculum. Locally, patches without ornamentation. 

Specimens Examined: 

B. convolvulacea, BRAZIL: G. Hatschbach 9193 (B, L); H. 

Schenck, Herb. Brazil 858 (B). 

OTHER SPECIES OBSERVED (Plate 3f-k).-Seed 

Structure: The seeds of B. epibaterium Martius ex A. DC., B. 

fagifolia, and B. glabra are quite similar in general shape to 

those of B. convolvulacea, but they may vary in the condition 

of the chalazal and micropylar ends, cells of which may be 

shriveled or inflated. 

Unfortunately, only immature seeds of B. smilacina A. DC. 

were available; however, their morphology corresponds to that 

of other species of section Enita. No seeds were available of B. 

inconspicua Brade, but the drawing of Brade (1945, pl. 4.12) 

shows the seed type particular to section Enita. 

In all specimens of the species observed, the chalazal side is 

flattened, probably from contact with the fruit wall, except in 

B. epibaterium (Scott Mori & Forbes Benton 12856), which 

has a more tapering, often somewhat asymmetric chalaza. Seed 

size in B. epibaterium tends to be a little smaller, as in B. convolvulacea. The mean seed size varies from 495 pm x 170 pm 

in B. epibaterium (Dos Santos 3408) to 660 pm x 150 pm in B. 

glabra (Laurito 81 72). The length: width ratio in section Enita 

varies between 2.9 and 4.4. In all specimens observed the anticlinal walls may be undulated; however, some variation exists 

in the presence and extent of the undulations. 

The seeds of the different collections of the 

widespread species B. glabra vary in respect to the above-mentioned characters. The specimens from Surinam differ by having conspicuous chalaza with inflated cells, which make the 

chalaza even broader than the central part of the seed. The cuticular structure of the chalazal cells is more pronounced, with 

a more randomly orientated zigzag ornamentation and distinct 

patches with a confluent cuticular pattern. 

The seeds of the collection from Cuba have few collar cells 

(mean=eight), with a mean length of 315 pm, and the ratio of 

collar-cell length to seed length is 2.0. This may be compared 

with, for instance, the collection from Costa Rica, the seeds of 

which have about 10 collar cells in the seed circumference. The 

collar cells have a mean length of 195 pm, and the ratio of collar-cell length to seed length is 3.4. 

Our samples of B. glabra var. amplifolia (A. DC.) L.B. 

Smith & B.G. Schubert and B. glabra var. cordifolia (C. DC.) 

Irmscher do not show specific characters and more resemble B. 

convolvulacea in having less-inflated chalazal cells. 

Seed Micromorphology: 

Remarks: 

Specimens Examined: 

(US); Scott Mori & Forbes Benton 12856 (US). 

B. epibaterium var. epibaterium, BRAZIL: Dos Santos 3408 

B. fagifolia, BRAZIL: Brade 19144 (B); Gaudichaud 1060 (P). 

B. glabra var. amplifolia, COLOMBIA: E.P. Killip 7722 (K). 

B. 

B. 

glabra var. cordifolia, CULTIVATED: van Veldhuizen 3 70 

(WAG). 

glabra var. glabra, COLOMBIA: T.A. Sprague 403 (K). 

COSTA RICA: Gomez Laurito 81 72 (CR). CUBA: c. Wright 

2627 (P). ECUADOR: Grubb C.S. 1199 (K). GUYANA: G. Cremers 81 (P). SURINAM: Indigen 270 (U); H.S. Irwin C.S. 

54738, 54818 (U). 

1.7. Section Pritzelia (Klotzsch) A. DC. 

PLATES 4,5a, b 

The section is characterized by male flowers with four tepals, free filaments, and anthers longer than the filaments and 

by female flowers with five tepals and undivided placentas. 

The leaves contain cystoliths. The section comprises about 100 

species and is the largest section in Brazil. Only a few species 

of this section have a wider distribution. The section includes 

the former section Saueria A. DC. 

SPECIES OBSERVED.-Seeds of 19 species have been observed using SEM. With a few exceptions, the seed structure 

corresponds with the ordinary begonia seed type. The seeds of 

the species differ in shape, size, and micromorphology to some 

extent. 

Seed Structure: The seed shape is ellipsoid to slightly narrowly ellipsoid. The mean seed size of the section type, B. 

dietrichiana Irmscher, is 350 pm x 195 pm, with a 

1ength:width ratio of 1.8. Within the section the mean seed 

length vanes from 3 10 pm in B. acida Vellozo to 620 pm in B. 

angulata Vellozo var. serrana Brade, and the 1ength:width ratio varies from 1.7 to 2.6, respectively. 

The anticlinal walls of the testa cells are straight or almost 

straight but are somewhat curved to slightly undulated in B. 

paranaensis Brade. The operculum is mostly nipple-shaped, 

sometimes broadly nipple-shaped, or obtusate in B. coccinea 

Hooker. 

The anticlinal boundaries are flat 

except for those of B. grisea A. DC. and B. itaguassuensis 

Brade, which have sunken and locally sunken anticlinals, respectively. The majority of the seeds have a fine, dense cuticular pattern of mainly short linear striae, more zigzag in B. epipsila Brade and B. paranaensis. In B. grisea the cuticle is almost 

without ornamentation. Five species deviate in cuticular sculpture. Begonia acida, B. hispida Schott, and B. sanguinea Raddi 

have a more pronounced and coarse, mainly zigzag pattern. In 

B. angulata and B. coccinea the cuticular pattern is very pronounced, consisting of long zigzag, sometimes even pleat-like, 

striae. The seeds of B. itaguassuensis also have a fine, dense 

cuticular pattern; however, they differ from the seeds of all other observed Pritzelia species by having anticlinal walls that are 

Seed Micromorphology: 
NUMBER 90 7 

more thickened and elevated, are straight and form a distinct 

polygonal pattern at the outside, and are undulated, with pockets at their bases. 

Begonia grisea and B. paranaensis resemble each other in 

shape and testa1 pattern. The seeds of B. bradei Irmscher, B. 

crispula Brade, B. dietrichiana, and B. olsoniae Smith & Schubert also resemble each other in some respects. The seeds of B. 

itupavensis Brade most resemble those of B. hookerana Gardner (Occhioni 4788) of section Steineria. 

The monotypic section Saueria A. DC. was 

eliminated by the placement of the Colombian type species B. 

sulcata Scheidweiler in Otto & Dietrich into synonymy with 

the Venezuelan species B. dichotoma Jacquin of section Pritzefia by L.B. Smith (1973). Although unfortunately no seeds of 

B. dichotoma were at our disposal, the seeds of B. sulcata quite 

closely resemble those of some other species of section Pritzelia from Brazil, e.g., B. angulata. 

B. acida, BRAZIL: cult., Boone-Hahn 108 (WAG); cult., Hort. 

B. angularis Raddi var. angularis, BRAZIL: D.R. Hunt 6470 

B. angulata var. angulata, BRAZIL: Hatschbach 8831 (L). 

B. angulata var. serrana, BRAZIL: Brade 17531 (U). 

B. bradei, BRAZIL: cult., Dept. Horticulture (WAG). 

B. coccinea, BRAZIL: Burchell219A (P); cult., Ziesenhenne s.n. 

B. crispula, BRAZIL: cult., Boone-Hahn 13 (WAG). 

B. dichotoma, COLOMBIA: cult., Boone-Hahn 25 (WAG, as B. 

B. dietrichiana, BRAZIL: A.P. Duarte 378 (US). 

B. epipsila, BRAZIL: cult., Boone-Hahn 27 (WAG). 

B. grisea, BRAZIL: St. Hilaire B 2027 (P); H.S. Zrwin C.S. 27654 

B. hispida var. hispida, BRAZIL: Bailey & Bailey 710 (L); VauB huegelii (Klotzsch) ex A. DC., BRAZIL: Altamira & Wolter 

B. itaguassuensis, BRAZIL: A. Lourteig 3236 (P). 

B. itupavensis, BRAZIL: Hatschbach 11 713 (U). 

B. olsoniae, BRAZIL: cult., van Veldhuizen 408 (WAG); E. 

B. paranaensis, BRAZIL: Hatschbach 8941 (L). 

B. petasitifolia Brade, BRAZIL: cult., van Veldhuizen 997 

B. reniformis Dryander, BRAZIL: Luederwaldt & Fonseca 

B. sanguinea, BRAZIL: Bailq & Bailey 706 (L). 

Remarks: 

Specimens Examined: 

bot. Litge. 

(K). 

sulcata). 

(Mole 

thier 542 (P). 

11 (U). 

Pereira 307 (RB, as B. vellozoana Brade, paratype). 

(WAG). 

18031 (B); Ynes Mexia 5148 (P). 

1.8. Section Philippomartia A. DC. 

PLATE 5c-e 

According to Irmscher (1 953), the species of this section 

closely resemble those of section Pritzelia except for some 

stigmatic characters and for a ring of tentacle-like processes at 

the top of the petioles. Such a ring also is known in a number of 

species of Pritzelia and in some other sections. The section 

comprises two or three species, B. leptophylla Taubert, B. 

membranacea A. DC., and B. neglecta A. DC. The taxonomic 

position of B. leptophylla is questionable (Doorenbos et al., 

1998). No seeds of B. neglecta were available. 

SPECIES OBSERVED.-Seed Structure: The seeds of B. leptophylla and B. membranacea resemble each other and agree in 

many characters with those of species in section Pritzelia, such 

as B. dietrichiana. The mean seed length of both species lies 

between 300 pm and 360 pm. The testa cells are polygonal, 

with straight anticlinal boundaries, and the operculum is nipple-shaped. 

The cuticular pattern is fine and 

dense; the striae are short linear in B. leptophylla and are zigzag in B. mem branacea. 

Specimens Examined: 

B. leptophylla, BRAZIL: A. Mo 4331 (MO). 

B. membranacea, BRAZIL: H.M. Curran 170 (US); Ex herb. 

Seed Micromorphology: 

horti Petropolitani Brasilia Castelnuovo (K). 

1.9. Sections Steineria (Klotzsch) A. DC. and Bradea Toledo 

PLATES 5f-n, 6a,b 

Section Bradea was separated from section Steinera by Toledo in 1946 on the basis of differences in the staminate flower. 

The sections Steineria and Bradea comprise about four species 

(seeds of B. caraguata-tubensis Brade were not available) and 

10 species, respectively. The two sections cannot be distinguished from each other on the basis of seed characters. 

The species of both sections are restricted to Brazil, with the 

exception of the questionable species B. opulijlora Putzeys 

from the former New Granada, which is based on a drawing of 

a horticultural specimen. 

TYPE SPECIES, SECTION Steineria.-Begonia hookerana 

Gardner (Plate 5fj). 

Seed Structure: Seeds narrowly ellipsoid to ellipsoid. 

Mean seed size 465 pm x 180 pm, length: width ratio 2.6. Collar cells elongated, other testa cells polygonal, with straight or 

slightly curved anticlinal walls. Operculum nipple-shaped. 

Anticlinal boundaries flat. Cuticular pattern consisting of mainly short linear striae. Seeds of collection Burchell2539 somewhat smaller, with locally undulated anticlinal walls and fainter cuticular pattern. 

B. hookerana, BRAZIL: BurcheN 2539 (K); P. Occhioni 4788 

(US). 

OTHER SPECIES OBSERVED, SECTION Steineria (Plate 

5g,l).-The seeds of B. arborescens Raddi var. arborescens 

and B. oxyphylla A. DC. resemble those of B. hookerana, especially collection BurcheN 2539. Their mean seed sizes vary between 330 pm and 415 pm. They all show locally undulated 

anticlinal walls with pockets at their bases and thin outer periclinal walls reflecting many small pits. The cuticular pattern of 

Seed Micromorphology: 

Specimens Examined: 
8 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

both species and of the variety B. arborescens var. confertiyora A. DC. show some minor differences. 

B. arborescens var. arborescens, BRAZIL: M Clausen 63 (P); 

B. arborescens var. confertiflora, BRAZIL: Gardner 602 (K, 

B. oxyphylla, BRAZIL: Znh. Vien s.n. (1828) (K). 

TYPE SPECIES, SECTION Bradea.-Begonia rufosericea Toledo (Plate 5m). 

Seed Structure and Micromorphology: Seeds closely resembling those of (especially) B. arborescens in general aspect 

and in above-mentioned characters, except for less-pronounced 

undulation of anticlinal walls. 

B. rufosericea, BRAZIL: Oswaldo Hanro s.n. (B); cult., van 

OTHER SPECIES OBSERVED, SECTION Bradea (Plates 5h,k,n, 

6a, b).-Some other seed collections of section Bradea observed, especially those of B. bidentata Raddi and B. polyandra 

Irmscher, resemble B. rufosericea. They differ by having 

curved anticlinal walls and a more distinct cuticular pattern of 

zigzag striae. The seeds of B. bidentata collection Riedel s.n., 

B. parvifolia Schott, and B. dentatiloba A. DC. show a more 

reticulate character set. 

B. bidentata var. bidentata, BRAZIL: A. Glaziou 11873 (K); G. 

B. dentatiloba, BRAZIL: L.B. Smith 1935 (K). 

B. parvqolia, BRAZIL: d2lleizette s.n. (L); A. Glaziou 15388 

B. polyandra, BRAZIL: Herb. Hieronymus s.n. (B, type). 

Specimens Examined: 

Grisebach s.n. (K); J. Miers 3291 (K). 

type). 

Specimens Examined: 

Veldhuizen 496 (WAG). 

Specimens Examined: 

Peckolt 75 (B); E. Pereira 287 (B); Riedel s.n. (U). 

(K); Brasilia Schott s.n. (B). 

1.10. Section Tetruchiu Brade 

PLATE 6c,g 

The monotypic section Tetrachia was established by Brade 

in 1945 on the basis of his newly described species B. 

quadrilocularis. This species was put into synonymy with B. 

egregia by Smith and Schubert (1955). The section is characterized by ovaries with four locules and by the presence of four 

styles and four-winged capsules. The number of tepals of the 

staminate and pistillate flower is two and six, respectively. The 

species is restricted to the state of Rio de Janeiro, Brazil. 

TYPE SPECIES.-Begonia egregia N.E. Brown (Plate 6c,g). 

Seed Structure: Seeds ellipsoid, 500-550 pm in length, 

250-300 pm in width, mean 530 pm x 275 pm, length: width 

ratio 1.9. Collar cells 155-230 pm in length, mean 190 pm, 

number in seed circumference about 12. Ratio of collar-cell 

length to seed length 1 : 2.8. Testa cells polygonal, anticlinal 

walls somewhat thickened, straight, slightly curved toward collar. Operculum broadly nipple-shaped. 

Seed Micrornorphology: Anticlinal boundaries straight. 

Cuticular pattern consisting of long linear and long zigzag striae, the latter locally more pronounced. 

Remarks: Seeds resemble those of B. itaguassuensis of 

section Pritzelia in the more thickened, straight, and elevated 

anticlinal walls. 

B. egregia, BRAZIL: J. Santos Lima s.n. (US, as B. quadrilocuSpecimens Examined: 

laris Brade, isotype); cult., Boone-Hahn 1 (WAG). 

1.1 1. Section Guerdtiu (Klotzsch) A. DC. 

PLATE 6d-Jh 

The placenta provides the most obvious character for this 

section. The placentas are two-parted, and the two lobes in 

each locule cling together and bear ovules on their outer sides 

only. The section contains about six species, three of which, B. 

maculata Raddi, B. corallina Camere, and B. undulata Schott, 

were observed. 

TYPE SPECIES.-Begonia maculata (Plate 6ef), the seeds of 

which are to some extent characteristic and deviate in size and 

shape from the two other species observed. 

Seeds elliptic, sometimes narrowly elliptic. 

Mean seed size 565 pm x 240 pm, length: width ratio 2.4. Collar cells relatively long, mean length 290 pm. Ratio of collarcell length to seed length 1.9. Testa cells adjacent to collar also 

elongated. Operculum long nipple-shaped. Anticlinal walls 

mainly straight. 

Seed Micromorphology: Anticlinal boundaries flat, locally 

sunken. Cuticular pattern short zigzag. 

Specimens Examined: 

B. maculata var. maculata, BRAZIL: Gentry & Zardini 49513 

(MO); Maas & Carauta 3149 (U). 

OTHER SPECIES OBSERVED.-Seed Structure and Micromorphology: The seeds of B. corallina and B. undulata are 

smaller, with a mean seed length of 495 pm and 460 pm, respectively. 

B. corallina, CULTIVATED: Boone-Hahn 114 (WAG). 

B. undulata, BRAZIL: Gaudichaud 1067 (P); cult., Hort. BogorSeed Structure: 

Specimens Examined: 

iensis 6071 AB (L). 

1.12. Section Lutistigmu A. DC. 

PLATE 6j-l,n 

The species of this section are characterized by the presence 

of five tepals in the pistillate flowers and by broad, lobed 

styles. The section contains three species, B. aconitifolia A. 

DC. and B. platanifolia Schott from Brazil, and B. leathermaniae O'Reilly & Karegeannes from Bolivia. 

TYPE SPECIES.-Begonia aconitifolia (Plate 6j). 

Seed Structure: Seeds ellipsoid, mean seed size 440 x 250 

pm, length: width ratio 1.8. Testa cells polygonal, with straight 

or slightly curved anticlinal walls. Anticlinal walls with more 

or less distinct pockets at bases. 
NUMBER 90 9 

Seed Micromorphology: 

dense, consisting of mainly short zigzag striae. 

Specimens Examined: 

B. aconitifolia, BRAZIL: Glaziou 13389 (B). 

OTHER SPECIES OBSERVED.-Seed Structure and 

Micromorphology: The seeds of B. platanifolia and B. leathermaniae closely resemble those of B. aconitifolia, differing 

mainly by their somewhat smaller size. 

B. leathermaniae, BOLIVIA: 0. Kuntze s.n. (B); M Moraes 1056 

B. platanifolia var. platanifolia, BRAZIL: Creagh s.n. (B); G. 

Cuticular pattern fine and very 

Specimens Examined: 

(US). 

Hatschbach 46298 (US). 

1.13. Section Pereira Brade 

PLATE 6m 

This monotypic section is characterized by two-lobate broad 

TYPE SPECIES.-Begonia edmundoi Brade, limited to Brazil. 

Seed Structure and Micromorphology: Seeds conforming 

to ordinary seed type, not showing distinguishing characters. 

Mean seed size 460 x 230 pm, 1ength:width ratio 2.0. Anticlinal walls straight and relatively thin. Cuticular pattern consisting of short linear to short zigzag striae. 

B. edmundoi, BRAZIL: E. Pereira 366 (B, cotype). 

stigmata that are almost kidney-shaped and cymatium-like. 

Specimen Examined: 

2. SECTIONS MAINLY CONFINED TO THE ANDEAN 

AND GUIANAN REGIONS 

Of the 12 Andean sections, five (Casparya, Gobenia, Hydristyles, Rossmannia, Warburgina) have a characteristic seed 

structure that distinguishes them from all other Neotropical 

sections. 

2.1. Section Casparya (Klotzsch) A. DC. 

PLATES 7-9 

Section Casparya has a very complicated taxonomic history. 

Shortly after its establishment as a genus by Klotzsch (1 855), 

A. De Candolle (1 864) extended it by including in it Klotzsch’s 

genera Zsoptevx, Sassea, and Stibadotheca and his newly described sections Aetheopteryx and Andiphila. Warburg (1 894) 

reduced the genus Casparya to sectional level and reduced De 

Candolle’s sections to subsections, actions that were later accepted by Irmscher (1 925). Moreover, he inserted Isopteryx in 

Andiphila. 

Smith and Schubert (1955) expressed the opion that the sympetalous character upon which the genera Begoniella Oliver 

and Semibegoniella C. DC. were based no longer was tenable. 

Consequently, the two species constituting genus Semibegoniella were placed into synonymy with Begonia grewiifolia (A. 

DC.) Warburg and so transferred to section Casparya. Smith 

and Schubert (1955) also merged the five species of the former 

genus Begoniella with section Casparya. 

The section is characterized by bifid, or many-, or irregularly 

branched styles and by triquetrous fruits that are not winged 

but have each of the edges terminating in a horn. The capsule 

dehisces at the edges. The plants are mostly erect semishrubs 

and usually grow above 2000 m elevation, especially in the 

Andean region of Colombia and Ecuador and in Venezuela. 

The section comprises about 40 species. 

Begonia urticae Group 

Begonia urticae LINNAEUS F. (Plate 7a, b,d).-Type species 

of section Casparya. 

Seed Structure: Seeds narrowly ellipsoid, micropylar ends 

flattened. Seed shape slightly varying from ellipsoid to more 

ovoid, with greatest width in middle or more to micropylar or 

chalaza1 end. Length 695-780 pm, width 370-390 pm, mean 

745 pm x 385 pm. Length: width ratio 1.9. 

Collar cells relatively short, 90-155 pm in length, mean 130 

pm, number in seed circumference about 15. Ratio of collarcell length to seed length 1 : 5.7. Longitudinal walls of collar 

undulated over entire length. Other testa cells polygonal, mostly not arranged in distinct rows. Anticlinal walls strongly undulated. Operculum nipple-shaped, sometimes almost flat. Ring 

of cells bordering collar slightly deepened. 

Seed Micromorphology: Anticlinal boundaries straight. 

Cuticular pattern rough, with relatively thick, linear to short 

linear or slightly undulated striae. No distinct patches. 

The 10 samples of B. urticae studied, the most 

common and most widely distributed species of section Casparya, show some variation in size and micromorphology. 

The seeds of the collections Schultes & Villarreal 7786, 

Dryander 1694, Bouman s.n., Bonpland s.n., and Irally 192 

closely resemble those of the above-described collection Harling et al. 20465. The mean seed size varies from 675 pm x 335 

pm (Schultes & Villarreal 7786) to 785 pm x 430 pm (Irally 

192). The 1ength:width ratio varies from 1.7 (Dryander 1694) 

to 2.0 (Schultes & Villarreal7786). The collections Bohlin 975 

(originally described as B. urticae var. retusa Smith & Schubert), Cuatrecasas 23515, de Escobar C.S. 8521 (originally described as B. antioquensis (A. DC.) Warburg), and Scott 

Hoover 442 deviate from the above-mentioned ones by having 

a smaller seed size and a more conspicuous undulation of the 

anticlinal cell walls. The mean seed size in collections Cuatrecasas 23515 and Scott Hoover 442 are 585 pm x 320 pm and 

605 pm x 3 15 pm, respectively. In both collections, however, 

the cuticle has undulated striae of normal thickness. The collection Scott Hoover 442 deviates by having larger collar cells 

with straighter longitudinal anticlinal walls. Mean length of the 

collar cells is 185 pm, with a collar-cell length to seed-length 

ratio of 1 :3.3. 

B. species, ECUADOR: van der Wer-& Palacios 9135 (MO); 

Remarks: 

Specimens Examined: 

Scott Hoover & Wormley 1822 (MO). 
10 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

B. urticae, COLOMBIA: MA. Bonpland s.n. (P); F. Bouman s.n. 

(AMD); Cuatrecasas 23515 (US); E. Dryander 1694 (US); 

de Escobar, Velasquez, & Marulanda 8521 (US); W. Zrally 

192 (K); W. Scott Hoover 442 (US); Schultes & Villarreal 

7786 (US). ECUADOR: J.E. & M Bohlin 975 (US); Harling 

et al. 20465 (US). 

OTHER SPECIES OBSERVED (Plate 7c, e-g).-Seed Structure 

and Micromorphology: The seeds of B. fuchsiijlora (A. DC.) 

A. Baranov & F.A. Barkley, B. gamolepis L.B. Smith & B.G. 

Schubert, B. longirostris Bentham (Harling & L. Andersson 

11608), and B. species (Scott Hoover & Wormley 1771) resemble those of B. urticae collection Bohlin 975 in size and in the 

strongly undulated anticlinal walls of both the testa and collar 

cells. Mean seed size varies from 545 pm x 310 pm in B. 

gamolepis to 630 pm x 375 pm in B. fuchsiijlora. All collections have a cuticle with mainly undulated striae of normal 

thickness except for collection Scott Hoover & Wormley 1771, 

which has a faint double structure. 

B. fuchsiiyora, ECUADOR: MT. Madison 6854 (US); W. Scott 

B. gamolepis, COLOMBIA: Barkley & Araque M. 185094 (US); 

B. longirostris, ECUADOR: Harling & L. Andersson 11608 

B. species, ECUADOR: Scott Hoover & Wormley I771 (MO). 

Specimens Examined: 

Hoover 515 (MO). 

Killip & A.C. Smith 16037 (B). 

(US). 

Begonia ferruginea Group 

Begonia ferruginea LINNAEUS F. (Plate 7h-k).-Seed 

Structure: Seeds narrowly obovate to obtriangular, micropylar end flattened, becoming acute at chalazal end. Length 

770-960 pm, width 265-325 pm, mean 880 pm x 290 pm. 

Length:width ratio 3.0. Number of collar cells in seed circumference about 14. Longitudinal walls of collar cells straight, 

sometimes slightly undulated. Other testa cells often elongated, 

with undulated anticlinal walls, cells of chalazal part more polygonal. Operculum nipple-shaped. 

Anticlinal boundaries flat. Cuticular ornamentation conspicuous, more or less plicate, composed 

of long, undulated foldings forming loose structure. Locally, 

patches with long, parallel striae. 

The seeds of two other collections are smaller 

and more variable in shape than the above-described collection 

(Langenheim 3387). Mean seed size is 775 pm x 345 pm in 

collection Grubb et al. 534 and is 7 10 pm x 345 pm in collection Steyermark & Dunsterville 100 784, with length :width ratios of 2.2 and 2.1, respectively. The seeds are ellipsoid, with 

rounded or more acute chalazal ends. Seeds of B. ferruginea 

var. dilatata Smith & Schubert are narrowly ellipsoid, with a 

mean seed size of 700 pm x 240 pm and a length: width ratio of 

2.9. There are about 16 collar cells in the seed circumference, 

and the chalazal end is rounded or somewhat acute. The cuticuSeed Micromorphology: 

Remarks: 

lar plicas and foldings are long and are undulated or somewhat 

zigzag. 

Specimens Examined: 

B. ferruginea var. dilatata, COLOMBIA: H. Garcia-Barriga 

12053 (US). 

B. ferruginea var. ferruginea, COLOMBIA: Grubb, Curry, & 

Fernandez-Perez 534 (US); J.H. Langenheim 3387 (US); 

Steyermark & Dunsterville 100784 (US). 

B. species, COLOMBIA: F.A. Barkley 38~120 (US). 

Begonia trispathulata Group 

Begonia trispathulata (A. DC.) WARBURG (Plate 8a, b).- 

Seed Structure: Seeds ellipsoid, micropylar end flattened, 

seeds 420470 pm in length, 280-285 pm in width, mean 445 

pm x 280 pm, length: width ratio 1.6. Seeds of collection L. 

Goldsmith I69 shorter than those of above-described collection 

(S.S. Tillett 739-585), with mean length of 375 pm. Collar cells 

relatively short, number in seed circumference about 15. Other 

testa cells polygonal, with undulated anticlinal walls. Operculum nipple-shaped. 

Anticlinal boundaries flat. Cuticle 

with so-called double structure: more elevated, short zigzag to 

star-shaped thick foldings and irregular, short zigzag to short 

linear underlying ornamentation. Locally, patches of labyrinthlike structure. 

B. trispathulata, VENEZUELA: L. Goldsmith I69 (VT); N. Ramirez 349 (MO); S.S. Tillett 739-585 (P). 

OTHER SPECIES OBSERVED (Plate 8c-l).-Seed Structure 

and Micromorphology: A number of species occurring in and 

mostly endemic to Venezuela resemble B. trispathulata in seed 

structure. All species are characterized by cuticles with a distinct double structure. Begonia brevipetala Warburg, B. mariae 

L.B. Smith, and B. trujillensis L.B. Smith agree in seed size 

and shape. In B. trujillensis the more elevated elements of the 

cuticular double structure are short undulated to short zigzag or 

star-shaped, in B. brevipetala they are short zigzag or starshaped, whereas in B. mariae they are mainly star-shaped. The 

star-shaped ornaments often show a central depression. 

The seeds of B. iipoiepis L.B. Smith differ in some characters. The seeds are quite variable'in shape, with a tendency to a 

tapering chalazal end. The mean seed size is 575 pm x 300 pm, 

with a 1ength:width ratio of 1.9. The anticlinal walls are less 

undulated and are sometimes almost straight to slightly curved. 

The cuticular double structure consists of short zigzag to starshaped elements. 

The seeds of B. toledana L.B. Smith & B.G. Schubert have a 

mean size of 500 pm x 300 pm. The anticlinal walls are distinctly undulated. The double structure is short undulated to 

short zigzag. 

The seeds of B. formosissima Sandwith have a mean size of 

635 pm x 395 pm. The anticlinal walls are less distinctly undulated. The double structure is composed of relatively dense, 

Seed Micromorphology: 

Specimens Examined: 
NUMBER 90 11 

mainly short zigzag elevations that obscure the underlying 

granular pattern. 

Specimens Examined: 

B. brevipetala var. brevipetala, VENEZUELA: €? J. Breteler 

3468 (US); L. Goldsmith 160 (VT); Steyermark & Mehlin 

109955 (U). 

B. fonnosissima, VENEZUELA: L. Goldsmith 166 (VT); RuizTeran & Figueiras 9306 (US). 

B. lipolepis, VENEZUELA: L. Goldsmith 167 (VT). 

B. mariae, VENEZUELA: L. Goldsmith 163 (VT). 

B. toledana var. toledana, COLOMBIA: Killip & A.C. Smith 

202 70 (B). VENEZUELA: Steyermark & Dunsterville 100604 

B. trujillensis, VENEZUELA: L. Goldsmith 168 (VT); S.S. Tillett 

(K). 

739-611 (US). 

Begonia pectennervia Group 

Begonia pectennervia L.B. SMITH & WASSHAUSEN (Plate 

8m,n).-Seed Structure: Seeds ellipsoid, 535-590 pm in 

length, 350-360 pm in width, mean 565 pm x 350 pm, 

1ength:width ratio 1.6. Collar cells relatively short, 85-160 pm 

in length, mean 125 pm, number in seed circumference about 

23. Ratio of collar-cell length to seed length 1 :4.5. Anticlinal 

walls of collar straight to slightly undulated, those of other testa cells strongly undulated. Anticlinals broad, without boundary. Outer periclinal walls rather shallow. Collar slightly tapering, operculum therefore rather small. Opercular ring adjacent 

to collar sunken. 

Seed Micromorphology: Anticlinals crossed by radiating 

longitudinal striae leaving “central field” of randomly orientated, small zigzag cuticular foldings of irregular thickness and elevation. 

The seeds of collection Holm-Nielsen et al. 

26762 differ slightly from the above-described collection 

(Holm-Nielsen et al. 26438) by having less-shallow testa cells 

and by having a cuticular ornamentation of short linear to short 

zigzag striae, sometimes with a faint double structure. 

Specimens Examined: 

B. pectennervia, ECUADOR: L. Holm-Nielsen et al. 26438, 

26762 (US). 

OTHER SPECIES OBSERVED (Plate 9a-e,g).-Seed Structure 

and Micromorphology: The seeds of B. colombiana Smith & 

Schubert, B. killipiana Smith & Schubert, B. longirostris (Lug0 

4699), and B. trispathulata (Steyermark 103480) resemble 

those of B. pectennervia in their broad anticlinal and shallow 

outer periclinal walls. The mean seed size varies from 440 pm 

x 275 pm in B. trispathulata to 655 pm x 470 pm in B. killipiana. The number of collar cells in the seed circumference varies from about 17 in B. colombiana to 22 in B. killipiana. The 

seeds of B. killipiana are characterized by short collar cells that 

vary in length from 65 pm to 130 pm, with a mean of 90 pm. 

The testa cells of B. killipiana and B. longirostris have a cuticular pattern similar to that of the central field, with short zigzag 

Remarks: 

to star-shaped foldings. Begonia colombiana has a very dense 

pattern of short zigzag and short undulated striae; B. trispathulata has a double structure of linear, undulated, or zigzag striae 

of varying length. The star-shaped cuticular foldings in B. killipiana occasionally have a central depression. The seeds of B. 

killipiana collections Killip 7994 and W.S. Hoover 463 resemble those of B. antioquensis collection Luteyn 12265, described 

below, especially in their micromorphological characters. The 

collar cells of B. killipiana and B. longirostris are or tend to be 

very short; those of B. trispathulata are relatively short. Of 

these four species, the seeds of B. killipiana most resemble 

those of B. hexandra, described below. 

B. colombiana, COLOMBIA: Schultes & Villaweal 7758 (us). 

B. killipiana, COLOMBIA: Killip 7994 (US); W. Scott Hoover 

B. longirostris, ECUADOR: Lug0 4699 (MO). 

B. trispathulata, VENEZUELA: Steyermark 103480 (US). 

Specimens Examined: 

27, 463 (US). 

Begonia antioquens is 

Begonia antioquensis (A. DC.) WARBURG (Plate 9f).-Seed 

Structure: Seeds ellipsoid, without distinct differentiation between operculum and collar, 5 10-600 pm in length, 295-360 

pm in width, mean 560 pm x 325 pm, 1ength:width ratio 1.8. 

No characteristic collar cells; all testa cells more or less isodiametric or somewhat irregular, not distinctly longitudinally 

elongated. Anticlinal walls pronounced, with rather obscure 

undulation, broader distally than proximally, and resembling 

rope netting. Micropylar end of seed rounded, without distinct 

hilum and micropyle. 

Seed Micromorphology: Anticlinal boundaries obscured, anticlinals rough cross-hatched. Cuticle distinctly double-structured. Elevated parts, about 12 per cell, irregularly round or 

star-shaped, with central depression and interconnected by radiating linear cuticular striae. 

B. antioquensis, COLOMBIA: J.L. Luteyn 12265 (US). 

Specimen Examined: 

Begonia hexandra 

Begonia hexandra IRMSCHER (Plate 9h).-Seed 

Structure: Seeds broadly ellipsoid, without distinct borderline between operculum and collar, 630-680 pm in length, 

505-565 pm in width, mean 660 pm x 540 pm, length: width 

ratio 1.2. No distinct differentiation between collar cells and 

other testa cells. Cells surrounding micropylar-hilar region 

somewhat more elongated, over 30 cells in circumference. 

Shape of testa cells irregular due to strongly undulated anticlinal walls. Anticlinals relatively broad, without boundary. Cell 

pattern difficult to recognize due to shallowness of outer periclinal walls. Micropyle a small, irregular bulge without distinct 

exostome and hilar scar. 
12 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Seed Micromorphology: Cuticular pattern, if present, reSpecimen Examined: 

duced, with longitudinal striae. 

B. hexandra, COLOMBIA: E.L. Core 1500 (US). 

Begonia diversistipulata Group 

Begonia diversistipulata IRMSCHER (Plate 9j).-Seed 

Structure: Seeds ellipsoid, with flat operculum, 345435 pm 

in length, 270-3 15 pm in width, mean 390 pm x 295 pm, 

1ength:width ratio 1.3. Collar cells 80-150 pm in length, mean 

1 10 pm, number in seed circumference about 13. Ratio of collar-cell length to seed length 1 : 3.5. Testa cells polygonal, arranged in rows. Anticlinal walls relatively thin, straight or 

slightly undulated. Micropyle almost not protruding. 

Anticlinal boundaries flat. Cuticular pattern consisting of rather loose, short, undulated striae to 

more condensed, short zigzag striae. 

Specimen Examined: 

B. diversistipulata, COLOMBIA: Giacometto 11 (B). 

OTHER SPECIES OBSERVED (Plate 9k).-The seeds of B. urnbellata H.B.K. resemble those of B. diversistipulata in the thin, 

straight or almost straight anticlinal walls and a simple cuticular pattern of short linear to short undulated striae. The seeds, 

however, differ in size and in the number of collar cells. Mean 

seed size is 590 x 350 pm with a length : width ratio of 1.7. The 

number of collar cells in the seed circumference is about 17. 

The collection Scott Hoover 443 differs from the above-described collection (Kill@ & Hazen 9165) by having a denser 

cuticular pattern, consisting of a double structure of mainly 

long zigzag striae. 

B. umbellata, COLOMBIA: Killip & Hazen 9165 (US); W. Scott 

Seed Micromorphology: 

Specimens Examined: 

Hoover 443 (US). 

Ungrouped Species 

SPECIES OBSERVED (Plate 91-n).-The seeds of Begonia 

montana Warburg, B. raimondi Irmscher, B. hirta (Klotzsch) 

Smith & Schubert, and one collection of B. formosissima (Lopez-Figueiras & Dugarte 29409) could not be incorporated 

into one of the groups of section Casparya described above. 

Begonia montana 

and B. formosissima have, respectively, mean seed sizes of 545 

pm x 340 pm and 565 pm x 360 pm and mean collar-cell 

lengths of 130 pm and 115 pm. Both have undulated anticlinal 

walls; those of the collar are straighter. 

The cuticular pattern is granular in B. montana and is granular to short zigzag and more uneven in elevation in B. formosissima. 

The mean seed sizes in B. raimondi and B. hirta are 790 pm 

x 395 pm and 725 pm x 385 pm, respectively. Mean collar-cell 

length in B. raimondi is 185 pm. The cuticular ornamentation 

Seed Structure and Micromorphology: 

in B. raimondi consists of dense, short undulated striae; in B. 

hirta it is more granular. 

Specimens Examined: 

B. formosissima, VENEZUELA: Lopez-Figueiras & Dugarte 

29409 (US); 

B. hirta var. hirta, PERU: R.J. Seibert 2385 (US). 

B. montana, VENEZUELA: Funck & Schlim 1044 (P, isotype); 

B. raimondi, PERU: A. Raimondi 2982 (B). 

H. Humbert 26725 (US). 

2.2. Section Rossmannia (Klotzsch) A. DC. 

PLATE 10a-c 

The taxon Rossmannia was first described by Klotzsch as a 

genus in 1855 and was transferred to sectional level by A. De 

Candolle in 1864. The monotypic section is characterized by 

pistillate flowers with two-parted placentas and by fruits with 

two very small wings and one large, subascending wing up to 

40 pm long, covered by two large, persistent bracteoles. Begonia rossmanniae is a climbing shrub that occurs in humid forests of Ecuador, Peru, and Colombia. 

TYPE SPECIES.-Begonia rossmanniae A. DC. (Plate 1Oa-c). 

Seed Structure: Seeds narrowly ellipsoid, micropylar and 

chalazal ends extended, one or both sides often curved, rendering seeds J- or slightly S-shaped. Micropylar end of seed composed of uncollapsed, air-filled cells, chalazal end tapering, 

with elongated, collapsed cells. Length 645-7 10 pm, width 

135-150 pm, mean 675 pm x 140 pm, 1ength:width ratio 4.8. 

Ratio of embryo-containing part of seed to total length of seed 

1 :2.8. Collar cells 105-225 pm in length, mean 160 pm, number in seed circumference about 9. Ratio of collar-cell length to 

seed length 1 :4.2. Longitudinal anticlinal walls of collar and 

adjacent cells straight or slightly undulated, those of operculum 

and chalaza always straight. Cells of operculum adjacent to 

collar elongated. Hilum sunken. 

Seed Micromorphology: Anticlinal boundaries straight, 

those of operculum sunken. Cuticle with linear to short linear 

pattern. Operculum with long linear striae, often running over 

entire length of cells. Collapsed outer walls reflecting many 

small, underlying pits. Locally, patches with less pronounced 

pattern. 

Specimens Examined: 

B. rossmanniae, COLOMBIA: H. W. Vogelmann C.S. 1297 (US). 

ECUADOR: E. Asplund 9304 (G); Holguer Lug0 S. 4824 

(AAU); J. Jaramillo & F. Coello 3218 (AAU). 

2.3. Section Hydristyles A. DC. 

PLATE IOd-k 

The section was established by A. De Candolle in 1859 and 

was retained as such by subsequent monographers (Warburg, 

1894; Irmscher, 1925). The three species recognized by Irmscher in 1925 have been increased to about 10 in subsequent 

years, including the transfer of two species from section Ruizo- 
NUMBER 90 13 

pavonia. The section deviates from related Andean sections by 

the presence of five unequal tepals and multifid styles in the female flower. The species are semishrubs and occur in Bolivia, 

Colombia, Ecuador, and Peru. 

TYPE SPECIES.-Begonia bridgesii A. DC. (Plate 1 Of). 

Seed Structure: Seeds ellipsoid, 440480 pm in length, 

205-235 pm in width, mean 460 pm x 215 pm, 1ength:width 

ratio 2.1. Collar cells 120-195 pm in length, mean 150 pm, 

number in seed circumference about 13. Ratio of collar-cell 

length to seed length 3.1. Longitudinal anticlinal walls of collar 

straight, those of other testa cells more irregularly curved, 

sometimes locally undulated. Testa cells somewhat elongated. 

Operculum nipple- to flat-nipple-shaped. 

Anticlinal boundaries flat. Cuticular pattern short linear; cuticle locally with patches of thin, 

somewhat dense linear to undulated striae. 

Specimen Examined: 

aff. B. bridgesii, BOLIVIA: Dereims s.n. (P). 

OTHER SPECIES OBSERVED (Plate 1 Od,e,g-k).-Seed Structure and Micromorphology: The seeds of the other species 

observed agree with those of B. bridgesii in the cellular pattern 

and in the short linear cuticular striae. They differ in shape, 

seed size, and the thickness and undulation of the anticlinal 

walls. The smaller seeds are found in B. juntasensis Kuntze and 

B. subcaudata Rusby ex L.B. Smith & B.G. Schubert, with 

mean seed sizes of 340 pm x 175 pm and 380 pm x 185 pm, respectively. The longest ones are found in B. santarosensis 

Kuntze, with a mean size of 630 pm x 205 pm and a 

length: width ratio of 3.1. The anticlinal walls vary from weakly undulated in B. subcaudata; to undulated in B. andina Rusby, B. juntasensis, and B. santarosensis; to strongly undulated 

in B. unduavensis Rusby. 

Thicker anticlinal walls with sunken anticlinals are found locally in B. juntasensis and B. unduavensis (G. Mandon 1089). 

More distinct pockets are found in B. juntasensis and B. santarosensis. 

B. andina, BOLIVIA: R.S. Williams 1566 (K). 

B. juntasensis, PERU: H.E. Moore Jr., Salazar, & Smith 8601 

B. santarosensis, BOLIVIA: s.n. (P). 

B. subcaudata, BOLIVIA: St. G. Beck 9253 (US). 

B. unduavensis, BOLIVIA: St.G. Beck 4691 (US); G. Mandon 

Seed Micromorphology: 

Specimens Examined: 

(US). 

1089 (K). 

2.4. Section Warburgina 0. Kuntze 

PLATE 1Ol 

The section was named by 0. Kuntze in 1893 on the basis of 

its then newly described species, B. comata. The section is monotypic and is restricted to Bolivia. The characters of the section agree to a large extent with those of section Hydristyles 

and also with those of sections Huszia (=Eupetalum) and 

Ruizopavonia. Section Warburgina differs from these sections 

by having pauciflorous inflorescences enveloped by numerous 

bracts. 

TYPE SPECIES.-Begonia comata Kuntze (Plate 101). 

Seed Structure: Seeds ellipsoid to narrowly ellipsoid, 

365435 pm in length, 170-185 pm in width, mean 420 pm x 

175 pm, 1ength:width ratio 2.2. Collar cells elongated, sometimes divided, 125-200 pm in length, mean 175 pm, number in 

seed circumference about 10. Ratio of collar-cell length to seed 

length 2.4. 

Anticlinal walls of collar straight or almost straight, those of 

other testa cells strongly undulated, with pockets at bases of 

curves. Testa cells somewhat elongated. Operculum nippleshaped. 

Seed Micromorphology: Anticlinal boundaries sunken, 

those of collar cells strongly undulated. Cuticular pattern short 

linear, mostly shortly undulated toward anticlinals. Periclinal 

walls thin, locally reflecting underlying pits. 

B. comata, BOLIVIA: St.G. Beck 12651 (US). 

Specimen Examined: 

2.5. Section Gobenia A. DC. 

PLATE 1 1 a-d,f;g 

The section was established by A. De Candolle in 1859 and 

was retained as such by subsequent monographers. It includes 

about 15 species and occurs in the nothern Andes, mainly Ecuador. Some of the distinguishing characteristics of the section 

are united filaments with sessile anthers and pistillate flowers 

that have extremely small styles with thick, auriculate stigmata. 

Fruits have three to four ribs or only one wing and are subtended by persistent bracteoles. The leaves are usually peltate. The 

species are climbing herbs or semishrubs. 

TYPE SPECIES.-Begonia maurandiae A. DC. (Plate 1 la,d). 

Seed Structure: Seeds ellipsoid, irregular in shape, often 

obliquely flattened at chalazal side, 500-610 pm in length, 

225-285 pm in width, mean 555 pm x 250 pm, 1ength:width 

ratio 2.2. Collar cells 125-290 pm in length, mean 185 pm, 

number in seed circumference about 15. Ratio of collar-cell 

length to seed length 3.0. Anticlinal walls of testa cells straight, 

sometimes slightly curved. Testa cells at chalazal end deeper 

due to elevated anticlinal walls. Operculum broadly nippleshaped, cells bordering collar elongated, forming distinct ring. 

Micropylar rim often oblique, hilum sunken. 

Seed Micromorphology: Anticlinal boundaries always 

straight. Cuticular pattern with long linear striae, sometimes 

slightly undulated. Locally, patches with zigzag striae. 

Seeds of collection Ed. Andrt 3315 (originally 

identified as B. hederacea A. DC.) deviate from above-described collection (W.H. Camp E 4974) in the following characters: mean seed size 420 pm x 170 pm, 1ength:width ratio 

2.5; number of collar cells in seed circumference about 11; testa cells with more pronounced anticlinal walls and locally 

sunken anticlinal boundaries. 

Remarks: 
14 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Specimens Examined: 

B. maurandiae, ECUADOR: W.H. Camp E 4974 (K). COLOMBIA: 

Ed. Andri 3315 (K). 

OTHER SPECIES OBSERVED (Plate 1 1 b,c,Jg).-Begonia pululahuana C. DC., B. secunda L.B. Smith & D.C. Wasshausen, 

B. sodiroi C. DC., and B. ynesiae L.B. Smith & D.C. 

Wasshausen closely resemble one another and agree with B. 

maurandiae (Camp E 4974) in general characters, including 

the large number of collar cells. The seeds are even more variable in shape, sometimes somewhat J-shaped and/or slightly 

distorted. Mean seed size is 545 pm x 2 15 pm in B. pululahuanu, 450 pm x 200 pm in B. secunda, 590 pm x 225 pm in B. 

sodiroi, and 560 pm x 220 pm in B. ynesiae. In the last species, 

the anticlinal walls are locally undulated. 

B. pululahuana, ECUADOR: E. W. Davis 500 (US). 

B. secunda, ECUADOR: A. Gentry & G. Shupp 26638 (MO). 

B. sodiroi, ECUADOR: Holm-Nielsen & Jeppesen 1276 (US). 

B. ynesiae, ECUADOR: Ynes Mexia 7706 (K, isotype). 

Specimens Examined: 

2.6. Section Meionanthera A. DC. 

PLATE 1 1 e, h 

The section was established by A. De Candolle in 1859 and 

has remained monotypic, with its only species B. holtonis A. 

DC. The section is characterized by very small, subglobose anthers on long slender filaments, elongate tepals of the pistillate 

flowers, ovaries with entire placentas, and three-celled fruits 

with one large wing and two highly vestigial wings. The species is restricted to Colombia. The seeds are not very characteristic and resemble the ordinary type of begonia seed. 

Seed Structure and Micromorphology: The seeds of B. holtonis var. holtonis are ellipsoid, with a mean size of 360 pm x 

195 pm. The testa cells are polygonal, with straight or very 

slightly undulated anticlinal walls, and the operculum is nippleshaped. The cuticular ornamentation is a fine, dense pattern of 

short linear or undulated striae. Locally, there are patches with 

a labyrinth-like structure. 

Specimens Examined: 

B. holtonis var. holtonis, COLOMBIA: F.A. Barkley C.S. 66 (US); 

Holton 725 (G, isotype); J.L. Luteyn C.S. 10395 (MO); Uribe 

Uribe 3878 (US). 

2.7. Sections Lepsia (Klotzsch) A. DC. and Zlttelbuchiu 

(Klotzsch) A. DC. 

PLATE 1 lj-n 

The species of the small sections Lepsia and Tittelbachia resemble each other in several floral characters and in outer appearance. 

TYPE SPECIES.-Begonia foliosa H.B.K. var. foliosa, type 

species of section Lepsia; B. fuchsioides Hooker var. fuchsioides, type species of section Tittelbachia. 

The seeds of the 

two type species resemble the ordinary type of begonia seed. 

Seed Structure and Micromorphology: 

They are mostly medium-sized, 355 pm x 180 pm and 490 pm 

x 240 pm, respectively, with distinctly elongated collar cells, 

variable undulation of the anticlinal testa cells, flat anticlinal 

boundaries, and a fine, dense cuticular pattern of mainly short 

linear or undulated striae. 

The seeds of the different varieties of B. foliosa are rather 

polymorphic. The seeds of B. foliosa var.putzeysiana (A. DC.) 

Smith & Schubert are relatively long, with a mean size of 585 

pm x 230 pm and a 1ength:width ratio of 2.5. The seeds of B. 

foliosa var. rotundata Smith & Schubert have a very dense cuticle that somewhat obscures the anticlinal walls. The synonymy of B. poeppigiana A. DC. with B. foliosa var. australis 

Smith & Schubert is sustained by seed micromorphology. 

B. foliosa var. australis, ECUADOR: Jameson s.n. (€3). PERU: 

B. foliosa var. foliosa, COLOMBIA: Oscar Haught 6159 (K); 

B. foliosa var. putzeysiana, COLOMBIA: Kill@ & A.C. Smith 

B. foliosa var. rotundata, COLOMBIA: McDougal & Roldan 

B. fuchsioides var. fuchsioides, COLOMBIA: H.H. Smith 1269 

(G); Killip & A.C. Smith 20552 (US). VENEZUELA: Maguire 

& Maguire 35301 (US). 

B. fuchsioides var. miniata A. DC., COLOMBIA: Uribe Uribe 

OTHER SPECIES OBSERVED.-The seeds of B. microphylla 

A. DC. are about 550 pm in length and differ fiom the species 

described above by having a more irregular seed shape, a 

broadly nipple-shaped operculum, and testa cells with more elevated anticlinal walls, causing a more shallow appearance. 

The seeds resemble those of species of section Gobenia. The 

collection P.E. Berry 3291 is more or less intermediate between the collection F.J. Breteler 4643 and B. foliosa collections. 

Specimens Examined: 

B. microphylla var. microphylla, VENEZUELA: P.E. Berry 3291 

(MO); F.J. Breteler 4643 (MO); L. Ruiz-Teran 393 (US). 

Specimens Examined: 

Matthias & Taylor 5905 (MO). 

PERU: Herb. Splitgerberianum (L). 

19817,20090 (US). 

3540 (US). 

5005 (US). 

2.8. Section Eupetalum (Lindley ex Klotzsch) A. DC., 

Including the Former Section Huszia (Klotzsch) A. DC. 

PLATES 12, 13a-c 

Section Eupetalum is mainly Andean, with species known 

from Ecuador and Peru. The type species, B. geraniifolia 

Hooker, has several synonyms. 

Smith and Wasshausen (1979, 1986) included the species of 

section Huszia in section Eupetalum. The species of former 

section Huszia occur in Bolivia, Peru, and Colombia, occasionally extending into Venezuela or occurring in Mexico. 

The species of the two sections as formerly recognized resemble each other quite closely and differ mainly in stem 

length. 
NUMBER 90 15 

The seeds of all species examined resemble the ordinary type 

of begonia seed. Although several species locally show crow’sfoot-like cuticular striae, the seeds lack distinct features characteristic at the sectional level. Moreover, the seeds show some 

variation in size, shape of operculum, thickness of anticlinal 

walls, and density of the cuticular pattern. 

FORMER SECTION Huszia.-Seed Structure and Micromorphology: The seeds of the former type species, B. octopetala l’Heritier, have a mean size of 340 pm x 180 pm and a 

length: width ratio of 1.9. The seeds of B. erythrocarpa A. DC., 

B. pastoensis A. DC., and B. pleiopetala A. DC. resemble 

those of B. octopetala in size, testa1 pattern, and in the very 

dense cuticular pattern, which consists of short zigzag and 

crow’s-foot-like striae. The synonymy of B. macbrideana Irmscher with B. erythrocarpa as stated by Smith and Wasshausen 

(1 984) is not substantiated by the seeds examined in this study. 

Begonia macbrideana has a different cuticular pattern and further differs by having an obtuse operculum, a larger number of 

collar and testa cells, and straight anticlinals. It has the biggest 

seeds observed in the former section Huszia, with a mean size 

of 455 pm x 300 pm and a length: width ratio of 1.5. 

The seeds of the three collections of the Mexican 

species B. monophylla Pavon ex A. DC. studied (all collected 

as B. unifolia Rose ex Trelease) closely resemble each other 

and differ from the seeds of all other Eupetalum species by 

having a broad, nipple-shaped operculum, broader anticlinal 

walls, and a coarser cuticular pattern of mainly zigzag striae. 

B. cinnabarina, BOLIVIA: R. de Michell6 (US). 

B. erythrocarpa, PERU: Wasshausen & Salas 1194 (K). 

B. hydrophylloides, COLOMBIA: M. Idrobo & Evans Schultes 

B. macbrideana, PERU: Weberbauer 201 1 (B). 

B. macra A. DC. aff., VENEZUELA: Steyermark & Rube 97300 

B. monophylla, MEXICO: C.G. Pringle s.n. (L, PRE); J.N. Rose 

B. octopetala, PERU: L. Holm-Nielsen C.S. 3404 (MO); A. Lopez 

B. pastoensis, COLOMBIA: F.C. Lehman 5404 (B); J. Triana s.n. 

B. pearcei, CULTIVATED: van Veldhuizen 580 (WAG). 

B. pleiopetala, PERU: Buchtien 653 (B); Weberbauer 6026 (B). 

B. serotina, BOLIVIA: W.H. Camp E 3716 (P). 

B. tumbezensis, PERU: Weberbauer 7685A (B). 

B. veitchii J.D. Hooker, PERU: A. Miguel Bang 1862 (B). CULTIVATED: van Veldhuizen 1108 (WAG). 

SECTION Eupeta1um.-Seed Structure and Micromorphology: The seeds of the three collections of the type 

species, B. geraniifolia, closely resemble one another. The 

mean seed size is 340 pm x 195 pm, with a 1ength:width ratio 

of 1.7. They resemble the seeds of the former section Huszia 

species B. cinnabarina Hooker, B. hydrophylloides Smith & 

Remarks: 

Specimens Examined: 

560 (US). 

(B). 

C.S. 9367 (P). 

C.S. 2709 (US); 0. Tovar 3600 (US). 

(PI. 

Schubert, B. pearcei Hooker, B. serotina A. DC., and B. tumbezensis Irmscher in general characters, their length: width ratio, and their more granular cuticular ornamentation. 

The seeds of the remaining species studied agree in the dense 

cuticular pattern but show some variation in other characters. 

Specimens Examined: 

B. aequatorialis Smith & Schubert, ECUADOR: W.H. Camp E 

3268 (MO). 

B. geraniifolia, PERU: Dowbey s.n. (P); A. Lourteig 31 17 (K); 

Sela 259 (B). 

B. novogranatae A. DC., COLOMBIA: M.T. Dawe 272 (K, as B. 

inanis Irmscher, isotype); P.J. Grubb, Curry, & FernandezPerez 628 (K). 

2.9. Section Apteron C. DC. 

PLATE 13de 

This monotypic section differs from the other sections by 

TYPE SPECIES.-Begonia exalata C. DC. 

Seed Structure and Micromorphology: 

having globose, wingless fruits; it is endemic to Ecuador. 

The seeds of B. exalata conform to the ordinary type of begonia seed. The mean 

seed size is 335 pm x 210 pm, with a 1ength:width ratio of 1.6. 

The anticlinal walls are straight, slightly curved, or obscured 

undulated. The operculum is nipple-shaped. The cuticular pattern is quite characteristic, consisting of very dense, mainly 

short zigzag striae almost without a distinct delimitation at the 

anticlinals, resulting in a woolly appearance of the seed surface. 

The seeds resemble those of B. pastoensis of section Eupetalum (Huszia). 

Specimen Examined: 

B. exalata, ECUADOR: Sodiro 597 (US, isotype). 

2.10. Section Burya (Klotzsch) A. DC. 

PLATE 13f-j 

Striking characters in section Barya are the presence of erect, 

lanceolate tepals in both staminate and pistillate flowers and 

unequal stamens united into an elongated column. Begonia 

monadelpha Ruiz & Pavon ex A. DC. and B. soror Irmscher 

occur in Peru; B. boliviensis A. DC. is known from Bolivia and 

Argentina. 

TYPE SPECIES.-Begonia monadelpha (Plate 13h). 

Seed Structure: Seeds ellipsoid to narrowly ellipsoid, 

somewhat irregular in shape. Length 450-555 pm, width 

210-240 pm, mean 510 pm x 225 pm, 1ength:width ratio 2.7. 

Collar cells elongated, 145-250 pm in length, mean 200 pm, 

number in seed circumference about 13. Ratio of collar-cell 

Length to seed length 1 : 2.6. Longitudinal anticlinal walls of 

collar straight, those of other testa cells straight, curved, or 

slightly undulated, with pockets. Operculum obtuse to broadly 

nipple-shaped. 
16 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Seed Micromorphology: Anticlinal boundaries straight or 

locally sunken. Cuticular pattern with linear or short undulated 

striae. 

The seeds of collection Barbour 3993 differ in 

several respects from the above-described collection Weberbauer 6714, being ellipsoid and somewhat smaller, with a 

mean seed size of 465 pm x 240 pm, a length: width ratio of 

1.9, and having thicker, straighter anticlinals. 

Specimens Examined: 

B. monadelpha, PERU: P. Barbour 3993 (MO); A. Weberbauer 

6714 (US). 

OTHER SPECIES OBSERVED (Plate 13J;g, j).-Seed Structure 

and Micromorphology: The seeds of B. soror quite closely 

resemble those of B. monadelpha collected by Weberbauer. 

They have a sunken micropyle and less undulated anticlinal 

walls. 

The seeds of B. boliviensis A. DC. differ from the abovementioned species and more resemble the ordinary begonia 

seed type. They have a mean seed size of 355 pm x 230 pm, 

with a length: width ratio of 1.5. The collar cells vary in length 

from 85 pm to 165 pm, with a mean of 125 pm. The ratio of 

collar-cell length to seed length is 1 :2.8. The operculum is nipple-shaped. The cuticular pattern is short linear to short undulated striae. 

Specimens Examined: 

B. boliviensis var. boliviensis, ARGENTINA: J. G. Hawkes C.S. 

3620 (MO); S. Venturi 4950 (MO). BOLIVIA: S.G. Beck 

6355 (US). 

Remarks: 

B. soror, PERU: J.J. Wurdack 1627 (US). 

3. SECTIONS OCCURRING BOTH IN BRAZILIAN 

AND IN ANDEAN REGIONS 

Only two sections have a distribution both from Brazil or Argentina and from the Andean countries. 

3.1. Section Pilderia A. DC. 

PLATE 13k,n 

Klotzsch’s genus Pilderia was reduced to sectional level by 

A. De Candolle (1 859). The section is characterized by staminate flowers with two to four tepals and pistillate flowers with 

five persistent tepals and undivided placentas. The plants are 

herbs or semishrubs with a yellowish pubescence. The section 

is probably monotypic. Begonia buddleiifolia A. DC. has a distribution from Brazil and Peru to Venezuela. 

TYPE SPECIES.-Begonia buddleiifolia A. DC. (Plate 13k,n). 

Seed Structure: Seeds conforming to ordinary seed type. 

Seeds ellipsoid, mean size 285 pm x 150 pm, 1ength:width ratio 1.9. Seeds of collection Allart 387 somewhat bigger: 320 

pm x 175 pm. Testa cells polygonal; anticlinal walls straight 

and weakly undulated at bases in collection Allart 387. Operculum nipple-shaped. 

Seed Micromorphology: Anticlinal boundaries flat, sometimes locally sunken. Cuticular ornamentation consisting of 

zigzag striae of various length. 

Specimens Examined: 

B. buddleiifolia, BRAZIL: E. Ule 6466 (K). ECUADOR: Holguer 

Lug0 s. 5042 (K). VENEZUELA: Allart 387 (B). NOUVELLE 

GRENADE: Goudot s.n. (P). 

3.2. Section Australes Smith & Schubert 

PLATE 131,m,o 

The section was established by Smith and Schubert in 1941 

and comprises herbaceous or almost herbaceous species with a 

small tuber at the stem base. The staminate and pistillate flowers have four and five tepals, respectively. The three styles are 

deeply two-divided on the back and are more or less wavy on 

the front. The section contains four species, all occurring in Argentina. Begonia micranthera, with several varieties, also extends to Bolivia and Peru. 

No seeds were available of B. parodiana L.B. Smith & B.G. 

Schubert and B. sleumeri L.B. Smith & B.G. Schubert. 

TYPE SPECIES.-Begonia micranthera Grisebach (Plate 

1 3m, 0). 

Seed Structure: Seeds elliptic. Mean seed size 405 pm x 

240 pm in B. micranthera var. micranthera, 420 pm x 230 pm 

in B. micranthera var. foliosa L.B. Smith & B.G. Schubert, and 

340 pm x 210 pm in B. micranthera var.fimbriata L.B. Smith 

& B.G. Schubert. Length:width ratios 1.7, 1.8, and 1.6, respectively. Relatively many testa cells, those adjacent to collar 

somewhat elongated, chalaza1 ones polygonal. Anticlinal walls 

straight, slightly curved, or slightly undulated. Operculum 

cone-shaped. 

Anticlinal boundaries flat, locally 

sunken in B. micranthera var.fimbriata. Cuticle with short, undulated striae and with slight double structure in B. micranthera var.$mbriata and var. foliosa. 

Specimens Examined: 

B. micranthera var.fimbriata, ARGENTINA: J. West 8413 (MO, 

isotype). 

B. micranthera var. foliosa, ARGENTINA: S. Venturi 3457 (US); 

J. West 6216 (MO). 

B. micranthera var. micranthera, ARGENTINA: Petersen & 

Hjerting s.n. (L). BOLIVIA: V.M Cardenas 4710 (US). 

OTHER SPECIES OBSERVED (Plate 131).-The seeds ofB. tafiensis Lillo closely resemble those of B. micranthera var. foliosa in size and morphological characters. 

B. tafiensis, ARGENTINA: s. Venturi 3093 (us). 

Seed Micromorphology: 

Specimen Examined: 

4. SECTIONS MAINLY CONFINED TO THE CENTRAL AMERICAN, 

MEXICAN, AND CARIBBEAN REGIONS 

Of the eight sections confined to Middle America, six could 

be studied for their seed structure. Of these only one, Urniformia, shows a characteristic seed structure that distinguishes 
NUMBER 90 17 

it from all other Neotropical sections. No seeds for study were 

available of the monotypic sections Cylindrobegonia and Parietoplacentalia. 

4.1. Section Urniformla Houghton ex Ziesenhenne 

PLATE 14u,b 

This section was draughted by Houghton in 1924 but wasn't 

published by Ziesenhenne until 1974. The section is monotypic 

and is restricted to Costa Rica, Guatemala, and Panama. The 

section is characterized by a one-celled ovary and a capsule 

with three long, hollow, fleshy horns. 

TYPE SPECIES.-Begonia heydei C. DC. (Plate 14a,b). 

Seed Structure: Seeds ellipsoid, 540-620 pm in length, 

255-295 pm in width, mean 585 pm x 280 pm, length: width 

ratio 2.1. Collar cells 165-244 pm in length, mean 205 pm, 

number in seed circumference about 1 1. Ratio of collar-cell 

length to seed length 1 :2.9. Testa cells polygonal, sometimes 

somewhat elongated toward collar. Anticlinal walls curved or 

slightly undulated. Operculum broadly nipple-shaped. 

Anticlinal boundaries flat. Cuticle 

smooth, without ornamentation; locally, striae on anticlinal 

walls of operculum. 

B. heydei, COSTA RIGA: Haber & Bello 7645 (MO); R.A. 

Seed Micromorphology: 

Specimens Examined: 

Ocampo 1323 (CR); Stone & Stone 2712 (US). 

4.2. Section Gireoudia (Klotzsch) A. DC. 

PLATES 14c-n, 15u-c 

Gireoudia was described by Klotzsch in 1854 as a genus. It 

was reduced to a section by A. De Candolle in 1859. Later, 

Gireoudia was considered to be a subsection of section Magnusia along with subsections Rachia and Psathuron. On the basis 

of priority, Gireoudia is now treated as a section including 

Magnusia and Psathuron. Rachia is now included in section 

Knesebeckia. Section Gireoudia includes the monotypic section Aurifonnia Ziesenhenne by the synonymy of B. bakeri C. 

DC. with B. cardiocarpa Liebmann (Burt-Utley, 1985). We accept the proposal by Burt-Utley (1985) to select B. plebeja 

Liebmann as lectotype of section Gireoudia above the more arbitrarily chosen species B. involucrata Liebmann (Baranov & 

Barkley, 1974). 

The Central American and Mexican species of the section 

have been revised by Burt-Utley (1985, 1990). The section is 

characterized by staminate and pistillate flowers with two tepals and pistillate flowers with two-parted placentas. The 

plants are rhizomatous perennials or suffrutescent herbs. The 

section comprises over 60 species, most of which are endemic 

and restricted to Mexico and Central America. Four species are 

reported from Colombia, Venezuela, and Guyana. 

TYPE SPECIES-Begonia plebeja (Plate 14c, f ). 

Seed Structure: Seeds ellipsoid. Mean seed size 365 pm x 

185 pm, 1ength:width ratio 2.0. Testa cells polygonal or more 

elongated. Anticlinal walls slightly curved. Operculum nippleto broadly nipple-shaped. 

Anticlinal boundaries flat. Cuticular pattern mainly consisting of short undulated striae. Locally, 

patches without distinct ornamentation. 

Specimen Examined: 

B. plebeja, COSTA RICA: John Taylor 17305 (Us). 

OTHER SPECIES OBSERVED (Plates 14d,e,g-n, 1 Sa-c).-The 

seeds of all species observed by us conform to the ordinary 

seed type. Seeds vary to some extent in size, number of testa 

cells, and in micromorphology. 

Seed length varies from 3 10 pm in B. jenmannii Tutin to 445 pm in B. crassicaulis Lindley and B. urophylla W.J. Hooker. The anticlinal walls are mostly straight, 

slightly curved, slightly undulated (B. barkeri Knowles & 

Westcott, B. multinervia Liebmann, B. urophylla), or undulated 

(B. sartorii Liebmann). 

The anticlinal boundaries are always flat. Cuticular ornamentation in most species is mainly 

granular to short zigzag, as in B. sericoneura Liebmann, or 

short undulated, as in B. nelumbiifolia Schlechtendal & Chamisso. The cuticular pattern is fine and very dense, as in B. cardiocarpa. 

B. barkeri, MEXICO: Bourgeau 2968 (L); Ch.L. Smith 690 (US). 

B. cardiocarpa, COSTA RICA: K. Utlq 591 7 (us). HONDURAS: 

P.C. Standley 11403 (us). NICARAGUA: Ziessenhenne s.n. 

(cult., as B. bakeri C. DC.). 

B. conchifolia Dietrich var. conchifolia, PANAMA: Wilbur 

24349 (CR). 

B. crassicauh, GUATEMALA: LA. Steyermark s.n. (us). 

B. fusca Liebmann, MEXICO: Botteri & Sumichrast 1631 (P). 

B. heracleifolia Schlechtendal & Chamisso var. heracleifolia, 

B. invohcrata, COSTA RICA: P.C. Standley 34241 (Us); Stanley 

B. jenmannii, BRITISH GUIANA (=Guyana): B. Maguire & FanB. multinervia, COSTA RICA: cult., van Veldhuizen 661 (WAG). 

B. nelumbiifolia, CULTIVATED: Gent, B.K. Boom 16850 (L). 

B. plantaginea Smith & Schubert, MEXICO: E. Matuda 11 7945 

B. sartorii, MEXICO: Bourgeau 2100 (L). 

B. sericoneura, HONDURAS: cult., van Veldhuizen 392 (WAG). 

B. squarrosa Liebmann, MEXICO: cult., van Veldhuizen 623 

B. urophylla, COSTA RICA: cult., van Veldhuizen 655 (WAG). 

Seed Micromorphologv: 

Seed Structure: 

Seed Micromorphology: 

Specimens Examined: 

MEXICO: Bourgeau 1583 (P). 

& Valerio 481 3 7 (US). 

shawe 23081 (U). 

(US). 

(WAG). 

4.3. Section Hexaptera Ziesenhenne 

PLATE 15d,e 

In 1974 Ziesenhenne established this monotypic section to 

accomodate B. oaxacana, formerly belonging to section Knesebeckia. The section is characterized by the presence of erect 
18 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

fruits with six small wings. This character, however, is not always present in this variable species. The species occurs in 

Panama, Costa Rica, Nicaragua, Guatemala, and southern 

Mexico. 

The seeds of B. oaxacana differ to some extent from the ordinary type of begonia seed. 

TYPE SPECIES.-Begonia oaxacana A. DC. var. oaxacana 

(Plate 15de). 

Seed Structure: Seeds ellipsoid. Mean seed size 480 pm x 

255 pm, 1ength:width ratio 1.9. Testa cells more or less polygonal, with straight, curved, or sometimes slightly undulated anticlinal walls; anticlinal walls thickened. Operculum nipple- to 

broadly nipple-shaped. 

Anticlinal boundaries always flat. 

Cuticular structure variable, from mostly faint linear, to short 

linear in collection McVaugh 10266, to smooth in collection 

Davidse et al. 26139. 

The seeds of collection Mc Williams & Molina 

42675 are comparable in size and shape; however, they differ 

in having a greater number of collar and testa cells, mainly 

straight anticlinal walls, and a more distinct cuticular pattern of 

short zigzag striae. 

The seeds of collection McVaugh 10266 strongly resemble 

those of B. udisylvestris C. DC., a species placed in section 

Ruizopavonia by Barkley and Golding (1974). The seeds of 

collection Davidse et al. 26139 resemble those of B. heydei 

(section Urniformia) in shape, the smooth cuticle, and the 

thicker anticlinal walls. 

Specimens Examined: 

B. oaxacana, COSTA RICA: G. Davidse et a[. 26139 (CR); P.C. 

Standley 38821 (US). MEXICO: R. McVaugh 10266 (US). 

NICARAGUA: Williams & R. Molina 42675 (us). PANAMA: 

R.L. Liesner 285 (P). 

Seed Micromorphology: 

Remarks: 

4.4. Section Dissepbegonia Ziesenhenne 

PLATE 15Jg 

This section was established by Ziesenhenne in 1948 on the 

basis of the newly described species B. cavum Ziesenhenne, 

found in a small cave in Oaxaca, Mexico. The section closely 

resembles section Knesebeckia but can be distinguished by the 

presence of placentas affixed to the inner walls of the locules. 

Later the section was extended with B. palmeri S. Watson 

(Barkley and Golding, 1974). 

SPECIES OBSERVED.-unfOrtunately no seeds were available 

of B. cavum. The seeds of B. palmeri are not characteristic and 

resemble the ordinary type of begonia seed. 

Seed Structure and Micromorphology: Seeds of B. palmeri 

have a mean seed size of 355 pm x 205 pm, with a 

1ength:width ratio of 1.7. The testa cells are polygonal, with 

straight or curved anticlinal walls. The operculum is nipple- to 

broadly nipple-shaped. The cuticular structure is faint-granular, 

with more prominent short linear or short undulated striae. 

Specimen Examined: 

B. palmeri, MEXICO: Ynes Mexia 219 (MO). 

4.5. Section Podandra A. DC. 

PLATE 15hJ 

The section is characterized by staminate and pistillate flowers with four and five tepals, respectively, and filaments united 

into a column. The section comprises the type species B. decandra Pavon ex A. DC. from Puerto Rico and Mexico. The inclusion of a second species, B. trichosepala C. DC. from Guatemala (Barkley and Golding, 1974), is disputed (Doorenbos et 

al., 1998). No seeds of the latter species were available. 

TYPE SPECIES.-Begonia decandra. 

Seed Structure: Seeds ellipsoid, mean size 370 pm x 180 

pm, length: width ratio 2.1. Collar cells distinctly elongated, 

other testa cells rectangular. Anticlinal walls of collar and testa 

cells varying between collections: strongly undulated in Krug 

& Urban 1121, undulated to weakly so in Hoffmann 876, and 

weakly undulated to almost straight in Sintenis 5341. Operculum nipple-shaped. 

Seed Micromorphology: Anticlinal boundaries varying 

among collections: mostly sunken in Krug & Urban 1121, locally sunken in Hofmann 876, and almost always flat in Sintenis 5341. Cuticular pattern consisting of short linear and short 

undulated striae. 

B. decandra, PUERTO RICO: 0. Hofiann 876 (B); Krug & 

Specimens Examined: 

Urban 1121 (L); P. Sintenis 5341 (P). 

4.6. Section Weifbachia (Klotzsch & Oersted) A. DC. 

PLATE 15k-o 

Weilbachia was originally described as a genus but was reduced to a section by A. De Candolle (1859). The section probably includes section Liebmannia Ziesenhenne, as it is similar 

to, if not indistinguishable from, section Weilbachia (Burt-Utley, 1985). The section is characterized by staminate flowers 

with two or four tepals and by pistillate flowers with two or 

three tepals and two-celled ovaries with two or three styles and 

two-parted placentas. The section is restricted to Central America and Mexico and comprises about 20 species (Burt-Utley, 

1985). 

TYPE SPECIES.-Begonia ludicra A. DC. (syn. B. liebmannii 

A. DC.). The original type species was described by Klotzsch 

as Weilbachia reptans, which was renamed Begonia liebmannii 

by A. De Candolle in 1864. 

Seeds 

ellipsoid, varying in size from 320 pm x 195 pm in B. aridicaulis Ziesenhenne to 4 15 pm x 2 15 pm in B. pustulata Liebmann, 

with length: width ratios of 1.6 and 1.9, respectively. Testa 

cells irregularly polygonal. Anticlinal walls undulated in most 

species but straight to curved in B. purpusii Houghton ex Ziesenhenne. Operculum nipple-shaped. 

SPECIES OBSERVED (Plate 1 5k-o).-Seed Structure: 
NUMBER 90 19 

Seed Micromorphology: Anticlinal boundaries always flat. 

Cuticular pattern short undulated, short linear, or granular. Outer periclinal cell wall sometimes rather thin, almost without cuticular ornamentation, and reflecting underlying pits, as in B. 

imperialis Lemaire. 

B. alice-clarkiae Ziesenhenne, MEXICO: cult., van Veldhuizen 

B. aridicaulis, MEXICO: cult., van Veldhuizen 529 (WAG). 

B. imperialis var. imperialis, MEXICO: DTH 5397 (L). 

B. ludicra A. DC., MEXICO: cult., van Veldhuizen 414 (WAG). 

B. purpusii, GUATEMALA: J.D. hyer 15321 (MO). MEXICO: E. 

B. pustulata, GUATEMALA: H. von Turckheim 1181 (US). 

Specimens Examined: 

497 (WAG). 

Matuda 5406 (MO). 

5. SECTION MAINLY OCCURRING IN BOTH ANDEAN 

AND MIDDLE AMERICAN REGIONS 

Only one section has a distribution more distinctly restricted 

to the Andes and Central America and Mexico. 

5.1. Section Ruizopavonia A. DC. 

PLATES 16,17u,b 

The section was established by A. De Candolle in 1859. Irmscher (1949) discussed the delimitation of the section. Begonia 

corredorana C. DC. and B. thiemei C. DC., affiliated to this 

section by Barkley and Golding (1 974), were included in section Gireoudia by Burt-Utley (1 985). 

Most species of the section have only two tepals in the staminate and pistillate flowers, but in some species there are three 

tepals in the staminate flowers and up to four tepals in the pistillate flowers. The connective of the stamens is a little extended. The styles are deeply two-parted and are sometimes divided 

again. The plants are suffrutescent, shrubby, or climbing, predominantly with pinnately veined leaves, and with small deciduous bracteoles. The section comprises about 35 species, mostly from the Andes, but eight species are reported from Central 

America and/or Mexico. 

TYPE SPECIES.-Begonia alnifolia A. DC. (Plate 16a,b). 

Seed Structure: Seeds ellipsoid, resembling ordinary begonia seed type. Mean seed size of collection Mocquerys 1219 

325 pm x 195 pm, 1ength:width ratio 1.7. Collar cells elongated, other testa cells relatively few in number. Anticlinal walls 

of testa cells thin and straight to curved. Operculum nippleshaped. 

Anticlinal boundaries flat. Cuticular pattern linear or undulated. Locally, patches without a 

smooth or fine structure. 

Seeds of B. aff. alnifolia collection A.C. Smith 

31 69 deviate by having somewhat larger seeds, undulated anticlinals, and a less dense cuticular pattern with underlying pits. 

Seed Micromorphology: 

Remarks: 

Specimens Examined: 

B. alnifolia, VENEZUELA: Mocquerys 1219 (P). GUYANA: A.C. 

Smith 31 69 (P). 

SPECIES COMPARABLE TOB. alnifolia (Plate 16c-h,k,I).- 

Seeds of most of the species observed of section Ruizopavonia 

resemble one another in their relatively small size, curved undulated anticlinals, and in their fine cuticular structure, consisting of linear or undulated striae. 

Mean seed length 

varying from 225 pm in B. corredorana C. DC., to 255 pm in 

B. cooperi C. DC., to 415 pm in B. carpinifolia Liebmann. 

Length: width ratios varying from 1.4 in B. peruviana A. DC. 

to 2.1 in B. convallariodora C. DC. Begonia carpinifolia seeds 

with relatively many testa cells. Seeds of B. bracteosa A. DC. 

resembling those of several Andean species in section Begonia, 

such as B. cyatophora Poeppig & Endlicher. Anticlinal walls 

varying from almost straight, to curved (B. peruviana), to distinctly undulated (B. seemanniana A. DC.). Compared with 

other species resembling B. alnifolia, seeds of B. bracteosa 

with thicker, curved to undulated anticlinal walls, locally with 

sunken anticlinal boundaries and coarser cuticular pattern of 

short linear or short undulated striae. 

B. bracteosa, PERU: Ellenberg 815 (U). 

B. carpinifolia, COSTA RICA: Kappelle & Monge 3635 (CR). 

B. consobrina Irmscher, COLOMBIA: Schultes & Villarreal 

B. convallariodora, COSTA RICA: Scott Hoover 582 (MO). PANB. cooperi, CULTIVATED: van Veldhuizen 396 (WAG). 

B. corredorana, COSTA RICA: A.F. Skutch 4733 (US). 

B. peruviana, PERU: Sandeman 4378 (K). 

B. seemanniana var. seemanniana, PANAMA: Seemann I661 

B. thiemei C. DC., MEXICO: Martinez Calderon 2258 (US). 

B. viridiflora A. DC. var. parvijlora Smith & Schubert, PERU: 

Mexia 04152 (MO, isotype). 

SPECIES DIFFERING FROM B. alnifolia (Plates l6j,m-o, 

17a, b).-The seeds of four species examined differ distinctly 

from those described above. 

Mean seed size 545 pm x 

295 pm, 1ength:width ratio 1.8. Anticlinal boundaries flat, with 

or without faint cuticular ornamentation. Outer periclinal walls 

of testa cells often with central field of short undulated striae 

and longer linear striae radiating toward anticlinal walls. 

Mean seed size 435 pm 

x 190 pm, 1ength:width ratio 2.3. Testa cells elongated, in regular rows in continuation of collar cells. Anticlinal walls of testa cells distinctly undulated. 

Seeds ellipsoid 

to narrowly ellipsoid, somewhat varying in shape and dimensions. Operculum obtuse, chalaza1 end extended. Mean seed 

size 385 pm x 150 pm, with 1ength:width ratio of 2.6. Anticlinal walls curved to undulated, locally with pockets. Anticlinal 

Seed Structure and Micromorphology: 

Specimens Examined: 

7704 (K). 

AMA: Seibert 207 (K). 

(K, lectotype). 

Begonia udisylvestris C. DC.: 

Begonia suprafastigiata Irmscher: 

Begonia cuatrecasiana Smith & Schubert: 
20 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

boundaries flat, crosshatched. Seeds of B. cuatrecasiana show 

tendency to scobiformy, as seen more extremely in section 

Rossmannia (see Smith and Schubert, 1946). 

Seeds narrowly ellipsoid, 

with obtuse operculum and extended chalazal end. Mean seed 

size 625 pm x 170 pm, length: width ratio 3.7. Testa cells elongated. Anticlinal walls elevated and slightly undulated, with 

many pockets along walls. Cuticular pattern mainly long linear 

striae. Seeds of collection Liesner 1023 somewhat smaller and 

more tapering toward chalazal end. 

The seeds of B. estrellensis resemble those of B. 

santarosensis of section Hydristyles. The seeds of B. udisylvestris resemble those of B. oaracana of section Hexaptera. 

B. cuatrecasiana, COLOMBIA: Forrero-Jaramillo 2403 (COL). 

B. estreffensis, COSTA RICA: Nelson Zamora C.S. 512 (CR). 

B. suprafastigiata, PERU: Weberbauer 7907 (B, holotype). 

B. udisylvestris, COSTA RICA: Burger & Stolze 5250 (CR). 

Begonia estrellensis C. DC.: 

Remarks: 

Specimens Examined: 

PANAMA: Liesner 1023 (L). 

6. SECTIONS WITH A WIDE NEOTROPICAL DISTRIBUTION 

The four sections discussed below comprise species distributed over a wide area, ranging from Brazil to Mexico, Two sections, Begonia and Knesebeckia, also have species in Asia. 

6.1. Section Dorafomefra (Klotzsch) A. DC. 

PLATE 17c-m 

The section is characterized in part by three two-parted styles 

with linear branches, undivided placentas, and palmately 

veined leaves. The species are self-fertilizing herbs. 

The section comprises about 12 species. Most species have a 

restricted distribution; B. filipes Bentham, B. hirtella Link, B. 

humilis Dryander, and B. semiovata Liebmann have a wider 

distribution in Central and South America. Begonia hirtella has 

been introduced and naturalized in, among other places, South 

Africa, Java, and Sri Lanka. 

TYPE SPECIES.-Begonia wallichiana Lehman (Plate 17d,g). 

Seed Structure: Seeds elliptic, 3 15-365 pm in length, 

185-205 pm in width, mean 340 pm x 195 pm. Length:width 

ratio 1.7. Collar cells relatively short, with mean length of 100 

pm. Testa cells isodiametric, anticlinal walls rather thick, 

straight or curved or somewhat undulated. Operculum nippleshaped. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticular 

pattern dense, consisting of mainly granular ornamentation. 

Specimens Examined: 

B. wallichiana, MEXICO: J.A. Duke M 3682 (MO); L.R. Stanford c.s. 972 (MO). 

OTHER SPECIES OBSERVED (Plate 17c,e,f;h-m).-The seeds 

of species of this section show some variation in size and micromorphology; the seeds of B. prieurii A. DC. and B. steyermarkii Smith & Schubert in particular are quite characteristic. 

Seed Structure and Micromorphology: The seeds of B. filipes, B. humilis, and B. semiovata are relatively small (e.g., 235 

pm in B. filipes), and the anticlinal walls are thinner than in the 

type species; however, they agree with B. wallichiana in general morphology and in the granular cuticular ornamentation. The 

seeds of B. tonduzii C. DC. also are shorter than 300 pm and resemble the above-mentioned species in most characters; however, they deviate by having a sharp demarcation of the anticlinal walls. 

The seeds of B. hirsuta Aublet and B. hirtella are about the 

same size as those of B. wallichiana and have a similar cuticular pattern, but they have more undulated anticlinals. Begonia 

hirsuta has seeds with thick anticlinal walls with obscured 

boundaries. Seeds of B. hirtella plants introduced to and escaped in Java and Sri Lanka more resemble seeds of B. hirsuta. 

The seeds of B. prieurii and B. steyermarkii distinctly deviate from the above-mentioned species. The periclinal walls of 

both the testa and collar cells reflect the presence of more or 

less evenly distributed knobbles. The anticlinal walls are rather 

thick in B. prieurii and are very thick and distinctly undulated 

in B. steyermarkii. The cuticular pattern consists of short and 

long zigzag elevated striae. The seeds of the two Brazilian collections of B. prieurii are to some extent intermediate between 

the Guianan collections and B. steyermarkii. The seeds of B. 

steyermarkii resemble seeds of certain species of section Casparya in general shape and in testa1 pattern. 

Specimens Examined: 

B. fifipes. PANAMA: LM. Johnston 108 (US). COLOMBIA: H.H. 

Smith 1264 (L); M. Thiebaut 41 (P). 

B. hirsuta, COSTA RICA: R. Liesner 4506 (MO). DUTCH GUIANA 

(=Surinam): Herb. Splitgerberianum (L). 

B. hirtella var. hirtella, BRAZIL: Lourteig 2308 (U). JAVA: 

Dorgelo 3085 (L). SRI LANKA: Jayasuriya 838 (PDA). 

B. humilis var. humilis, ECUADOR: Egger 1404 (L). TOBAGO: 

Krug & Urban 3040 (L). VENEZUELA: LA. Steyermark 

95138 (US). 

B. prieurii, FRENCH GUIANA: Granville 2519 (us); c. sastre 

1698 (US), 1733 (U). BRAZIL: H.S. Irwin C.S. 48223 (US); T. 

Plowman C.S. 8243 (US). 

B. semiovata, BRITISH GUIANA (=Guyana): B. Maguire & Fanshawe 32449 (US). COSTA RICA: Tonduz 9588 (US). 

B. steyermarkii, BRITISH GUIANA (=Guyana): R.S. cowan & 

Soderstrom 1841 (US). 

B. tonduzii, COLOMBIA: A. Gentry & E. Forero 7327 (MO). 

COSTA RICA: Grayum 8132 (CR). 

6.2. Section Begonia Baranov & Barkley 

PLATES 18, 19 

Baranov and Barkley (1972) named section Begonia on the 

basis of the rules and recommendations of the International 

Code of Botanical Nomenclature (ICBN). The section comprises parts of the former section Begoniastrum A. DC. The 

taxonomic delimitation of section Begoniastrum changed sev- 
NUMBER 90 21 

era1 times. According to Baranov and Barkley (1972), section 

Begonia includes the former subsection Eubegonia Warburg 

and the sections Moschkowitzia (Klotzsch) A. DC. and Cyatocnemis (Klotzsch) A. DC., but Knesebeckia, reduced by 

Warburg (1 894) to a subsection, is again a section in its own 

right. Section Begonia has no unique characters and is circumscribed by a combination of more general character 

states, such as staminate flowers with four (sometimes two) 

tepals and oblong to linear anthers that are longer than the filaments and pistillate flowers with usually five (sometimes 

six) tepals and bipartite placentas. With about 75 species, it is 

the section with the largest number of species in the Neotropics, but according to Barkley and Golding (1 974), it also includes about 12 Asian species. 

Some groupings can be made on the basis of seed structure. 

The most distinct is the B. cucullata-B. fischeri group, the 

species of which mainly are found in Brazil, Argentina, Paraguay, and Uruguay, although B. fischeri has a more widespread 

distribution. 

Several species, often endemic, are present in the Caribbean 

region. The seeds of these species may resemble those of the 

section type, B. obliqua, or they may resemble the seeds of the 

more widespread B. guaduensis. 

Begonia obliqua Group 

Begonia obliqua LINNAEUS (Plate 18a,d).-Type species of 

section Begonia. 

Seed Structure: Seeds elliptic, 295-420 pm in length, 

180-205 pm in width, mean 360 pm x 195 pm, 1ength:width 

ratio I .8. Testa cells polygonal. Anticlinal walls thin, straight, 

or almost straight, but undulated at bases. Operculum nippleshaped. 

Anticlinal boundaries flat. Cuticular pattern faint, reflecting underlying pits; if present, pattern 

consisting of short zigzag striae. 

Specimen Examined: 

B. obliqua, MARTINIQUE: Duss 973 (US). 

CARIBBEAN SPECIES OBSERVED (Plate 18b,c,e-h,k).-The 

seeds observed of species originating from the Caribbean region all belong to the ordinary begonia seed type and more or 

less resemble B. obliqua. 

Begonia rotundifolia Lamarck and B. glandulifera Grisebach quite closely resemble B. obliqua in size, shape, and the thin anticlinals and 

outer periclinal walls. 

The seeds of B. odorata Willdenow and B. retusa Schulz resemble each other by the undulated anticlinal walls of testa and 

operculum cells and are to some extent similar to those of the 

B. cucullata-B. fischeri group. The two species differ from 

each other somewhat in seed size and cuticular pattern. 

The seeds of B. cubensis Hasskarl and of B. plumieri A. DC. 

var. barahonensis O.E. Schulz differ by having almost straight 

anticlinals and more zigzag striae. 

Seed Micromorphology: 

Seed Structure and Micromorpholology: 

Specimens Examined: 

B. cubensis, CUBA: J. Linden 1730 (GENT, as B. lindeniana A. 

DC., isotype). CULTIVATED: Ziesenhenne s.n. 

B. glandulifera, TRINIDAD: Van Steenis 20304 (L). 

B. odorata, ST. VINCENT: c. Morton 5066 (us). 

B. aff. odorata, DOMINICA: J. Jkrkmie I I05 (P). 

B. phmieri var. barahonensis, SANTO DOMINGO: Padre Miguel 

B. retusa, SABA: A.L. Stofsers 3116 (u). 

B. rotundifolia, WEST INDIES: Hortus Bot. Liege (cult.); Hortus 

Bot. Nancy (cult.). 

MAINLY ANDEAN SPECIES OBSERVED (Plate 1 Ilj,l,m).-Seed 

Structure and Micromorphology: The seeds of B. guaduensis 

H.B.K., B. cyatophora (type species of former section Cyathocnemis), and B. portillana S. Watson strongly resemble 

those of B. odorata in shape, size, undulated anticlinal walls, 

and in the mainly granular to short linear cuticular pattern. The 

two samples of B. cyatophora studied by us differ somewhat in 

the extent of undulation. 

The seeds of B. altoperuviana A. DC. and B. barrigae Smith 

& Schubert also conform to the ordinary seed type and do not 

show special characters. 

Specimens Examined: 

B. altoperuviana, BOLIVIA: Weddell 4556 (P). 

B. barrigae, COLOMBIA: cult., van Veldhuizen 872 (WAG). 

B. cyatophora, PERU: Ellenberg 735 A (U); Y. Mexia 8128 

B. guaduensis, GUYANA: Maas & westra 3877 (u). PANAMA: 

B. portillana, MEXICO: Dunn, Le Doux, & Torke 21820 (MO). 

Fuertes 432 (L). 

(MO). 

C.E. Smith Jr. & H. Morgan Smith 3272 (US). 

Begonia cucullata-Begonia fischeri Group 

Begonia cucullata WILLDENOW (Plate 19a-d).-Seed Structure and Micromorphology: Among the specimens assigned 

to this species, three seed types are encountered: (1) narrowly 

ellipsoid seeds having an obtuse micropylar end with sunken 

hilum and an extended chalazal end (often J-shaped), a mean 

size of 670 pm x 185 pm, and a 1ength:width ratio of 3.6; (2) 

obovate to narrowly obovate seeds having an obtuse operculum 

with sunken hilum, a somewhat extended chalazal end, a mean 

size of 550 pm x 220 pm, and a length: width ratio of 2.5; and 

(3) elliptic seeds resembling the ordinary begonia seed type, 

having a nipple-shaped operculum, a mean size of 3 15 x 200 

pm, and a 1ength:width ratio of 1.6. 

Most seed collections of B. cucullata var. cucullata belong to 

the first seed type, with the exception of collections Bartlett 

21359 and Jorgensen 3473, which belong to the second and 

third types, respectively. 

The seeds of B. cucullata var. arenosicola (C. DC.) Smith & 

Schubert belong to the third seed type, with the exception of 

collection Fiebrig 5125, which belongs to the first seed type. 

Testa cells adjacent to the collar are elongated in the first two 

seed types and are more polygonal in the third type. In spite of 
22 

the above-mentioned differences, all three seed types fully 

agree in their testal pattern, namely, undulated anticlinal walls 

and a granular to short linear cuticular structure. 

Specimens Examined: 

B. cucullata var. arenosicola, ARGENTINA: T.hl Pedersen 

10232 (P). PARAGUAY: E. Hassler 6130 (P, isotype); E. 

Hassler 7884 (P, isotype); K. Fiebrig 5125 (L). 

B. cucullata var. cucullata, BRAZIL: d’ANeizette s.n. (L); Irwin, 

Maxwell, & Wasshausen 19961 (P); Y. Mexia 5190 (U); Hj. 

Moskn 1598 (P). PARAGUAY: Jorgensen 3473 (US). URUGUAY: H.H. Bartlett 21359 (P). 

OTHER SPECIES OBSERVED (Plate 19e-m).-The seeds of all 

collections of the more widespread B. fischeri Schrank are narrowly ellipsoid with an obtuse micropylar end and with a sunken hilum and an extended chalaza1 end. They resemble the similar seed type of B. cucullata; however, they are somewhat 

longer, with a mean seed length of 795 pm. The anticlinal walls 

are mostly somewhat more strongly undulated, with pockets at 

their bases. The cuticular pattern is less prominent, and the outer walls sometimes reflect underlying pits. Begoniafischeri 

var. klugii Irmscher differs in its relatively longer micropylar 

end, it being one-third of the seed length, whereas this is about 

one-fourth the seed length in the other collections. 

The seeds of B. alchemilloides Meisner ex A. DC., B. balansae C. DC., B. descoleana Smith & Schubert, B. meridensis A. 

DC., B. per-dusenii Brade, B. schmidtiana Regel, and B. subvillosa Klotzsch, mainly from Brazil and/or Paraguay and Argentina, resemble the elliptic seed type of B. cucullata in 

shape, undulated anticlinals, and in the granular to short linear 

cuticular pattern. The species vary somewhat in seed length, 

with a mean from 345 pm in B. subvillosa var. leptotricha (C. 

DC.) Smith & Wasshausen to 430 pm in B. descoleana. They 

also may show some differences in testal pattern, e.g., B. perdusenii with broad anticlinals and B. alchemilloides with a lesspronounced cuticular pattern. 

B. alchemilloides, BRAZIL: H.S. Irwin C.S. 34478 (K). 

B. balansae, PARAGUAY: B. Balansa 3281 (P). 

B. descoleana, BRAZIL: G. Hatschbach 9944 (U). 

B. fischeri var. fischeri, BRAZIL: G. Hatschbach 5338 (L); 

Prance & Siha 59701 (U). COSTA RICA: B. Hamme18377 

(MO). VENEZUELA: Steyermark & Rube 96605 (P); Steyermark C.S. 100258 (P). 

Specimens Examined: 

B. fischeri var. klugii, PERU: G. Klug 3389 (MO, cotype). 

B. fischeri var. macroptera (Klotzsch) Irmscher, BRAZIL: B.B. 

B. fischeri var. palustris (Bentham) Irmscher, COLOMBIA: 

B. meridensis, VENEZUELA: Holst & Liesner 3159 (MO). 

B. per-dusenii, BRAZIL: L.B. Smith, Klein, & Schnorrenberger 

B. schmidtiana, BRAZIL: B.K. Boom 15916, cult., Hort. Gent 

Pickel 2466 (US). 

Hartweg 1022 (P). 

1 I728 (K). 

(L). 

SMITHSONIAN CONTRIBUTIONS TO BOTANY 

B. subvillosa var. leptotricha, PARAGUAY: K. Fiebrig 5354 (P, 

B. subvillosa var. subvillosa, BRAZIL: G. Hatschbach 21525 

isotype). 

(L); L.B. Smith & Reitz 1269 (US). 

Ungrouped Species 

Begonia organensis BRADE (Plate 1 8n).-Seed Structure 

and Micromorphology: The seeds of this species conform to 

the ordinary seed type and cannot be linked to either of the 

above-described groups. The mean seed size is 555 pm x 255 

pm, with a 1ength:width ratio of 2.2. The anticlinal walls are 

straight or slightly curved and sometimes are locally undulated. 

The distinct cuticular pattern consists of linear to undulated 

striae of varying length, continuous across the anticlinals. 

B. organensis, BRAZIL: D. Sucre C.S. 3005 (MO). 

Specimen Examined: 

6.3. Section Knesdeckia (Klotzsch) A. DC. 

PLATES 20,2 la-g 

Section Knesebeckia was formerly considered a subsection 

of section Begoniastrum A. DC. by Warburg (1894). The section now includes the former subsection Rachia Klotzsch of the 

former section Magnusia Klotzsch (Irmscher, 1960) and the 

monotypic section Quadriperigonia Ziesenhenne, which was 

eliminated by the synonymy of the type species, B. abaculoides 

Ziesenhenne, with B. boissieri A. DC. (Smith and Wasshausen, 

1983). 

The species of this section are very diverse. Some show a 

close resemblance to species of Begonia, others are similar to 

species of Eupetalum, Ruizopavonia, and some other sections 

with bifid placentas. The section is characterized by anthers 

that are globose or obovoid and are much shorter than the filaments, which often are monodelphous. Some species are tuberous, and several also produce bulbils in the leaf axils. The section comprises about 67 Neotropical species, with a 

concentration in Mexico (Burt-Utley, 1985), and according to 

Barkley and Golding (1974), also includes about 10 Asian species. 

The seeds of the species observed all conform to the ordinary 

begonia seed type; however, the section is not homogenous in 

seed structure and shows variation in micromorphological 

characters. 

TYPE SPECIES.-Begonia incarnata Link & Otto (Plate 

20a, d ). 

Seed Structure: Seeds elliptic, mean size 360 pm x 180 

pm, length: width ratio 2.0. Anticlinal walls of testa cells thin, 

undulated. Operculum nipple-shaped. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticular structure mainly short linear. 

Specimen Examined: 

B. incarnata var. incarnata, MEXICO: Liebmann 177 (US). 
NUMBER 90 23 

OTHER SPECIES OBSERVED (Plates 20b,c,e-n, 2 la-g).- 

Seed structures vary between the Central American and the 

Mexican species. 

Seed Structure and Micromorphology: Begonia kellermannii C. DC. and B. peltata Otto & Dietrich resemble B. incarnata in the thin, undulated anticlinal walls. The seeds of B. boissieri and B. ludwigii Irmscher resemble each other in the 

straight to curved anticlinal cell walls and in the short zigzag to 

granular cuticular ornamentation. 

The seeds of B. gracilis H.B.K. and B. sandtii Ziesenhenne 

strongly resemble those of some species of section Doratometra, especially B. wallichiana, in the relatively small seed size 

(mean seed length 300 pm in B. gracilis; 340 pm in B. sandtii), 

straight or curved anticlinal walls, and the dense cuticular pattern, consisting of a mainly granular ornamentation. The seeds 

of B. angustiloba A. DC., B. falciloba Liebmann, B. ignea 

Waxzewicz ex A. DC., and B. unij7ora S. Watson resemble one 

another in thicker, straight or curved anticlinal walls and a 

mainly short zigzag cuticular ornamentation. 

The seeds of the South American species studied deviate 

from the above-mentioned ones. The seeds of B. maynensis A. 

DC. and B. oellgaardii L.B. Smith & Wasshausen closely resemble one another in their short lengths, 280 and 295 pm, respectively, and a length: width ratio of 1.5. The seeds have 

broad anticlinals caused by thickening of the outer periclinal 

walls bordering the anticlinal walls. Anticlinal boundaries are 

locally sunken. The cuticular pattern is mainly granular to short 

undulated. The seeds of B. wollnyi Herzog resemble the abovedescribed ones somewhat in their small size and in projecting 

anticlinals. 

The seeds of the Brazilian species B. dichroa Sprague and B. 

olbia Kerchove resemble each other in size, with a mean length 

of 420 pm; thin, straight anticlinal walls; flat anticlinal boundaries; and the mainly granular to short linear cuticular ornamentation. 

B. angustiloba, MEXICO: ML. Diguet s.n. (P). 

B. boissieri, MEXICO: cult., van Veldhuizen 747 (WAG). 

B. dichroa, BRAZIL: cult., Ziesenhenne s.n. 

B. falciloba, MEXICO: M Bourgeau 649 (P). 

B. gracilis var. gracih, MEXICO: Pringle 11452 (L). 

B. ignea, COSTA RICA: H. Pittier & T. Durand 1299 (P). 

B. kellermannii, GUATEMALA: cult., Ziesenhenne s. n. 

B. ludwigii, ECUADOR: cult., Ziesenhenne s.n. CULTIVATED: 

B. maynensis, BRAZIL: Prance C.S. 7409 (U). 

B. oellgaardii, ECUADOR: M.A. Baker 6396 (US). 

B. olbia, BRAZIL: cult., van Veldhuizen 434 (WAG). 

B. peltata var. peltata, MEXICO: cult., Hort. Bot. Gent, B.K. 

B. sandtii, MEXICO: cult., Ziesenhenne s.n. 

B. uniyora, MEXICO: J. Roybal647 (US). 

B. wollnyi, BOLIVIA: cult., van Veldhuizen 435 (WAG). 

Specimens Examined: 

van Veldhuizen 618 (WAG). 

Boom 14288 (L). 

6.4. Section Donuldiu (Klotzsch) A. DC. 

PLATE 2 1 h-0 

This section, comprising seven species, is characterized in 

part by pinnate leaves and by male flowers with two 

(sometimes four) tepals and ellipsoid anthers that are about as 

long as the filaments. No seeds were available for B. burlemancii Brade or B. egleri Brade. 

TYPE SPECIES.-Begonia ulmifolia Willdenow was described in 1805. It has a wider distribution than other species in 

the section, being found in Venezuela, Guyana, and Trinidad, 

and it has been introduced and is naturalized in Sri Lanka (Jayasuriya, 1983). 

Seeds ellipsoid, mean size 290 pm x 190 

pm, 1ength:width ratio 1.5. Testa cells polygonal, with curved 

anticlinal walls. Sample from Sri Lanka differs by more slender 

seeds with thinner, straight anticlinal walls. Seeds resembling 

those of B. gracilis (section Knesebeckia). 

Seed Micromorphology: Cuticular pattern consisting of 

short linear to almost granular and short zigzag striae. 

Specimens Examined: 

B. ulmifolia, TRINIDAD: W.H.A. Hekking 1428 (U). SRI LANKA: 

A.H.M Jayasuriya 998 (PDA). 

OTHER SPECIES OBSERVED.-TWO of the other species observed are limited to Bolivia, and two are limited to Brazil (see 

“Specimens Examined,” below). 

The seeds of the 

other four species studied also are relatively small, not exceeding 400 pm, and conform to the ordinary begonia seed type. 

They differ in anticlinal walls, from straight in B. dasycarpa A. 

DC. to undulated in B. chaetocarpa Kuntze var. chaetocarpa. 

They resemble the seeds of B. ulmifolia in cuticular pattern except for B. dasycarpa, which has long zigzag striae. 

B. bangii Kuntze, BOLIVIA: A. Miguel Bang 406 (K). 

B. chaetocarpa var. chaetocarpa, BOLIVIA: 0. Kuntze s.n. (B, 

B. chaetocarpa var. glabriflora Smith & Schubert, BOLIVIA: 

B. dasycalpa, BRAZIL: A. Glaziou 15388 (P). 

B. jairii Brade, BRAZIL: G. Pedro do Cavalo 752 (US). 

Seed Structure: 

Seed Structure and Micromorphology: 

Specimens Examined: 

isotype). 

H.H. Rusby 690 (US, isotype). 

Discussion 

SEED MORPHOLOGY 

The seeds of about 235 Neotropical Begonia species, representing 39 sections, were studied using SEM. No seeds were 

available for study in the monotypic sections Cylindrobegonia, 

Parietoplacentaria, Plurilobaria, and the dubious monotypic 

section Dasystyles. 

Almost all seeds studied show differentiation between collar 

and other testa cells, characteristic for Begonia. The only exceptions are found in species B. antioquensis and B. hexandra 
24 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

of section Casparya, the seeds of which show neither a distinct 

collar nor a borderline with the operculum. 

As is the case in African and Asiatic begonias, the seeds of 

the Neotropical species exhibit an appreciable diversity in seed 

size and structure. This diversity is not as wide as in the African begonias (de Lange and Bouman, 1992), in which all sections are distinguishable from one another on the basis of seed 

characters. 

The seeds of NeotroPical begonias vary in shape from ahost 

globular to narrowly ellipsoidal. The lowest length: width ratio 

(1.2) is found in B. hexandra; the highest one (8.1) is found in 

B. fruticosa (section TrendelenbUrgia). Seed shape may be determined by flattened, extended, or swollen chalaza1 ends. A 

flat chalazal end is caused contact with the Ovary Or fruit 

wall. Most seeds have a mean length between 300 pm and 600 

Pm; the shortest, with a mean length of225 Pm, are found in B. 

corredorana (section Ruizopavonia), and the longest ones, 

fruticosa. 

The mean number of collar cells in the seed circumference is 

mostly between 10 and 12; however, this may be as low as 

eight in a collection of B. glabra (section Enita) and as high as 

collar cells are mostly distinctly elongated; their mean length 

varies from 100 pm in B. wallichiana (section Doratometra), 

to 290 pm in B. maculata (section Gaerdtia), and to 325 pm in 

B. fruticosa. The mean collar-cell 1ength:seed length varies 

from 1.9 in B. maculata to 5.7 in B. urticae (section Casparya). 

The other testa cells are mostly polygonal, sometimes elongated near collar cells. Their anticlinal walls are straight (as in 

sections Pritzelia or Ewaldia) or are curved or undulated (as in 

sections Casparya or Hydristyles). The anticlinal boundaries 

are mostly flat but are sometimes sunken or locally sunken (as 

in section Warburgina). 

The cuticular ornamentation varies greatly in pattern, thickness, and roughness. The cuticular pattern may be granular, linear, undulated, or zigzag. The surface of the cuticle may be 

smooth (section Urnifonnia), faint, pronounced, or even forming a net-like structure of pleats (section Trachelocarpus). The 

roughness varies from fine and dense (section Latistigma) to 

rough, as in many species of section Caspalya. Sometimes the 

structure of the underlying periclinal wall is reflected, showing 

pits or pockets at the bases of undulated anticlinal walls. A cufoldings next to a regular cuticular is especially found 

in section Casparya. 

main areas in which Neotropical begonias are found. The sections with a specialized seed structure have a limited number of 

species, with the exception of sections Casparya and Gobenia. 

Of the Brazilian or mainly Brazilian sections, the following 

five sections have a characteristic seed structure. 

In section Trachelocarpus the seeds are relatively large, with 

a rather unique cuticular structure consisting of upright or folded-over pleats. The seeds of section Solananthera are long because of their extended chalazal end. The long seeds in section 

Trendelenburgia have both extended micropylar and chalaza1 

ends. In section Enita (Wageneria) the micropylar andor chalazal cells of the seeds are uncollapsed and air-filled, resembling balloons. In section Scheihveileria the surface of the flattened chalaza is pronounced because of deep, collapsed testa 

cells and an often broadly nipple-shaped operculum. 

The other Brazilian or mainly Brazilian sections do not have 

a characteristic seed structure at the sectional level, and most of 

seed type. In some cases one or more species within a section 

may deviate from this ordinary type. 

The possible relationship between sections Ewaldia and Scheihveileria, as suggested by the successive of the 

1894; Irmscher, 1925), is supported by seed The 

seeds of the type species B. of section Ewaldja resemble 

those of section Scheihveileria. 

The section Pritzelia is quite diverse in seed morphology. 

Within the section, a number of species observed deviate by 

having a more pronounced and coarse zigzag cuticular striae. 

Seed structure does not provide arguments for a separate settion Bradea as proposed by Toledo (1946). The seeds of the 

type species B. rufosericea closely resemble those of B. arborescens of section Steineria. 

The seeds of species of section Latistigma conform to the ordinary begonia seed type and resemble the seeds of some species of section Gireoudia, e.g., B. cardiocarpa. 

Of the sections mainly confined to the Andean and Guianan 

regions, five have characteristic seeds. In section Caspatya the 

seeds are recognizable by a combination of characters, especially the roughness of the testa1 surface, the mostly undulated 

anticlinals, the flat operculum, and sometimes the double structure of the cuticle. On the basis of a combination of these charmatch the subsectional classification of Irmscher (1925). Unfortunately, we cannot contribute to the discussion on the status 

of the former sections Begoniella and Semibegoniella because 

with a mean length of 1450 klm, are found in a collection of B. their species have seeds that conform to the ordinary begonia 

23 in a collection of B. pectennervia (section Casparya)* The two sections in Die naturlichen Pflanzenfamilien (Warburg, 

title with a double structure, i.e., with more elevated, scattered acters, 'Pecies groups can be but d' not 

DELIMITATION AND INTERRELATIONSHIPS OF 

NEOTROPICAL SECTIONS 

no seeds of these taxa could be examined. 

Section Rossmannia is the only Andean section having narrowly elliptic seeds with a swollen micropylar and an extended .. 

Within the Neotropical begonias, a number of sections show 

a special seed structure characteristic at the sectional level. All 

these sections have a relatively restricted geographical distribution; one or more of such sections are found in each of the three 

chalazal end. The seeds of B. rossmanniae resemble those of 

the B. cucullata-B. fischeri group (section Begonia) in shape 

and size, but they differ in the presence of straight anticlinal 

walls. 
NUMBER 90 25 

Seed structure in section Hydristyles is quite diverse. Seed 

micromorphology provides arguments for the inclusion of section Warburgina in section Hydristyles. The seeds of B. comata 

resemble seeds of species of section Hydristyles, like B. andina 

and B. unduavensis, in their elongated testa cells with strongly 

undulated walls. 

The seeds of section Gobenia are characterized by an irregular seed shape, a broadly nipple-shaped operculum, and an often flattened chalaza1 end with more elevated anticlinal walls. 

The seeds of section Gobenia resemble those of section Scheidweileria. Seed micromorphology supports the opinion of Smith 

and Wasshausen (1986) that B. sodiroi belongs to section 

Gobenia. The synonymy of B. sodiroi with B. oaxacana (section Hexaptera) as stated by Barkley and Golding (1 974) is not 

supported. 

The other mainly Andean sections all have seeds that conform to the ordinary seed type and only differ in details. Seed 

micromorphology does not contradict a relationship between 

sections Lepsia and Tittelbachia and supports the inclusion of 

section Huszia in section Eupetalum, as proposed by Smith and 

Wasshausen (1979, 1986). The seeds of the section type, B. geraniifolia, resemble those of a number of species of the former 

section Huszia. The placement of B. micranthera in section 

Australes (Smith and Schubert, 1941) also is supported by seed 

morphology. 

Begonia exalata, of the monotypic section Apteron, differs in 

hit structure and growth form, but the general morphological 

characters as well as the seed structure indicate a relationship 

with section Eupetalum. Begonia trujillensis was initially 

placed in section Apteron by its author on the basis of the regularly two-parted styles (Smith, 1973; Barkley and Golding, 

1974). Seed micromorphology clearly shows that this species 

belongs to section Casparya. 

The seeds of the type species of section Barya, B. monadelpha, and to a lesser extent the seeds of B. soror, agree with 

those of section Gobenia in their somewhat irregular shape and 

the broadly nipple-shaped opercula. 

The elimination of the monotypic Colombian section Saueria by synonymy of its type species, B. sulcata, with a species 

of section Pritzelia, is supported by seed morphology. 

Of the sections mainly confined to the Central American and 

Caribbean regions and Mexico, only the seeds of the monotypic section Urniformia show special characters. Begonia heydei 

is the only Neotropical species having seeds with a smooth cuticle. 

The seeds of the large section Gireoudia all conform to the 

ordinary begonia seed type and do not show a distinct grouping 

of the seeds. The inclusion of section Auriformia is not disproved by seed micromorphology. The seeds of the former type 

species B. bakeri (= B. cardiocarpa) resemble those of other 

collections of B. cardiocarpa and of B. involucrata. Seed morphology does not provide arguments for or against a separate 

section Dissepbegonia. The section most probably should be 

included in section Knesebeckia, as the kind of placentation 

also is found in some species of this section (Doorenbos et al., 

1998). 

The seeds of the other three sections all have relatively small 

seeds and do not show special characters. 

The majority of the seeds of all seven sections not restricted 

to one of the main geographical areas conform to the ordinary 

seed type. Seed micromorphology generally only provides restricted arguments for delimitation of sections or relationships 

between these sections. The sections Ruizopavonia, Doratometra, and Begonia are mutually difficult to delimit (Irmscher, 

1949). All three sections are rather heterogenous in seed structure and have species or a group of species with a deviating 

seed structure. The transfer of B. filipes, B. humilis, and B. hirtella from section Begonia to section Doratometra as referred 

to by Barkley and Golding (1974) is supported by seed micromorphology. The conspecificity of B. filipes and B. hirsuta as 

suggested by Burt-Utley (1984) is not supported by seed micromorphology. The seeds of B. prieurii and B. steyermarkii of 

section Doratometra deviate from the seeds of the other species of this section by the presence of knobbles on the outer 

periclinal walls and by thicker, distinctly undulated anticlinal 

walls. The seeds of B. steyermarkii resemble those of some 

species in section Casparya. 

The seeds of the species of section Ruizopavonia are rather 

heterogenous. The seeds of a number of species, for example, 

B. bracteosa and B. suprafastigiata, resemble those of some 

species of section Begonia. The scobiform seeds of B. cuatrecasiana resemble those of section Rossmannia, and seeds of 

B. estrellensis resemble those of section Hydristyles. Seed micromorphology does not support the synonymy of B. udisilvestris with B. carpinifolia (Barkley and Golding, 1974). Begonia udisilvestris most probably does not belong to section 

Ruizopavonia. Doorenbos et al. (1998) placed B. oaxacana of 

the monotypic section Hexaptera together with B. udisylvestris in section Parietoplacentalia. This opinion is supported 

by the resemblance of the seeds of B. udisilvestris to those of 

B. oaxacana. 

Seed micromorphology could not provide arguments for or 

against the inclusion of B. thiemei and B. corredorana in section Gireoudia as indicated by Burt-Utley (1985). 

Within section Begonia, the B. cucullata-B. fischeri group 

is characterized by a testa1 pattern of undulated anticlinal walls, 

a granular to short linear cuticular structure, and, partly, a narrowly ellipsoid or obovate seed shape. 

The inclusion of section Cyathocnemis in section Begonia is 

supported by seed structure. 

POSSIBLE INTERCONTINENTAL RELATIONSHIPS 

Our knowledge of the intercontinental relationships of begonias is rather meager. The great majority of Begonia sections 

have a distribution that is restricted to one continent. Warburg 

(1894) classified all Begonia species into African, Asian, and 

American sections; however, Irmscher (1 925) was of the opin- 
26 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

ion that section Begoniastrum was intercontinental, comprising 

species of American and Asian origin. Baranov and Barkley 

(1972) changed the name of section Begoniastrum to Begonia, 

in accordance with the ICBN, and split off a separate section 

Knesebeckia. According to Barkley and Golding (1974), sections Begonia and Knesebeckia comprise about 12 and about 

10 Asian species, respectively. Serious doubts, however, exist 

about the validity of the delimitation of these sections. Doorenbos et al. (1 998) moved the Asian species of both section Begonia and section Knesebeckia to section Diploclinium. 

As shown in this study, the seeds of the American representatives of section Knesebeckia are quite diverse in structure. 

Seeds of the Asian section Diplocliniurn observed by us also 

conform to the ordinary Begonia type: they are mostly relatively small and show some variation in anticlinal walls and cuticular structure. Seeds of the Asian Knesebeckia species also show 

appreciable variation in seed morphology and do not closely 

resemble the American species of section Knesebeckia or those 

of section Diploclinium. Of the Asian species of section Begonia, only B. labordei L6veillC could be studied by us. The seeds 

of this species conform to the ordinary begonia seed type and 

do not show any specific character that points to or against a relation with the American species. 

A. De Candolle included in his section Casparya a number 

of Indo-Malaysian species, such as B. multangula Blume, B. 

robusta Blume, and B. silletensis (A. DC.) C.B. Clarke, now 

belonging to the Asian section Sphenanthera A. DC. The seeds 

of species in section Sphenanthera are relatively small and 

have a mainly granular structure. The seeds of the above-mentioned species fit well with those of section Spenanthera. There 

are no arguments for a direct relationship of section Caspatya 

with Asian species. 

As far as we know, no suggestions have been made about intercontinental relationships between Neotropical and African 

begonias. 

SEED STRUCTURE IN RELATION TO DISPERSAL 

AND GROWTH FORM 

Field observations on the dispersal of Begonia seeds are rare. 

The great majority of the Neotropical Begonia species seems to 

be wind dispersed (anemochory; see van der Pijl, 1972). Seed 

dispersal is mostly anemoballistic, i.e., the winged fruit is shaken by wind and the seeds are gradually released through pores 

or slits. This means of dispersal holds for the majority of the 

Neotropical sections, including large sections, such as Begonia, 

Gireoudia, Knesebeckia, and Pritzelia, which generally grow 

in a more open and often dry vegetation. Capsular motion may 

be promoted by elongated frutescences exposed above the 

leaves, enlargement of the median wing into a vane, or by persistent bracteoles. The seeds of these species are medium-sized 

and conform to the ordinary seed type. 

Special adaptations to wind dispersal are the increase of the 

surface to volume ratio as seen in narrowly ellipsoid fusi- or 

scobiform seeds, the decrease of specific gravity (mass) caused 

by uncollapsed, air-filled testa cells, as in balloon seeds, and 

promotion of laminar air flow by surface roughness. These adaptations also may occur in varying combinations. Adaptations 

in seed shape in combination with inflated cells are known in 

sections Rossmannia, Solananthera, and Trendelenburgia and 

in the B. cucullata-B.$scheri group of section Begonia. Typical balloon seeds also are found in section Enita, whereas a 

more pronounced surface caused by more raised anticlinal 

walls is seen in seeds of sections Scheidweileria and Gobenia. 

Wind dispersal, however, seems neither likely nor effective in 

species from humid and/or closed-forest vegetations. 

On the basis of fruit and seed morphology, it is rather speculative to suggest other types of dispersal in Neotropical begonias. Secondary seed dispersal by rain-wash may occur in the 

majority of the begonias, including the wind dispersed ones. 

Rain-wash is supposed to be the most important means of dispersal for most species of the African sections Filicibegonia, 

Loasibegonia, and Scutobegonia, growing in the sheltered environment of the tropical rain forest where wind is an ineffective vector in dispersal. Their fruits do not open but rot away. 

Seeds of species in these sections are small and are often provided with a thick, pronounced, cuticular ornamentation (de 

Lange and Bouman, 1992). Such a combination of fruit and 

seed characters is not found among the Neotropical begonias. 

A number of Neotropical Begonia sections have fruits and 

seeds that are not adapted to wind dispersal. The species of the 

epiphytic section Trachelocarpus are characterized by solitary, 

subsessile fruits with narrow wings somewhat hidden underneath the leaves, as expressed by the name B. rhizocarpa (= B. 

depauperata), and large seeds with a very pronounced cuticular 

pattern. The means of seed dispersal is unknown. A combination of accidental dispersal by rain and by adhering to animals 

(epizoochory) seems to be the most probable way of dispersal. 

The species of section Caspatya act as rattleburrs; their fruits 

have horns instead of wings, and the seeds are provided with 

striking cuticular patterns, such as prominent, sometimes plicate foldings or a double structure that might function in dispersal by rain wash. Seeds seem to be dispersed in different 

ways. Passing animals may catch the horns and shake the 

fruits, scattering seeds (zooballistics), or seeds may adhere to 

animals. 

None of the Neotropical begonias have fruits adapted to rain 

ballistics as in the Asian section Platycentrum, where the two 

shorter wings form a cup to catch raindrops. Moreover, none of 

the Neotropical begonias have fruits or seeds that seem adapted 

to frugivores or to ant dispersal. Animal-dispersed begonias 

with fleshy, often colored fruits are known in a number of African sections. These sections show trends toward bigger seeds, 

loss of cuticular ornamentation, and a thick exotesta, and they 

may have aril-like appendages (de Lange and Bouman, 1992). 

In the Neotropics, seeds without cuticular ornamentation are 

known only from B. heydei (section Urniformia). This species, 

from the wet montane zone of Central America, deviates from 
NUMBER 90 

all other begonias by a one-celled ovary with three long, hollow, fleshy horns. Fruit dehiscence and seed release have not 

been described in detail. 

The wingless fruits of B. exalata (section Apteron) suggest 

another means of dispersal; however, the seeds are of the ordinary begonia type, and seed micromorphology does not provide an indication for dispersal. 

The means of seed dispersal often seems to be related to habitat and growth form (Burt-Utley, 1985). Begonias with special 

adaptations to wind dispersal are mostly climbers and/or epiphytes or have a tendency to do so. For example, this holds in 

sections Enita, Rossmannia, Solananthera, Trendelenburgia, 

27 

and in species of section Gobenia. The rattleburrs of section 

Casparya grow in the wet montane forest, where wind is less 

effective. 

Seed dispersal of the Neotropical begonias, and most probably that of the Asian ones, distinctly differs from seed dispersal 

in African begonias. In the Neotropical begonias wind dispersal is predominant, and alternative types of dispersal are restricted to a limited number of sections. In Africa only about onefifth of the Begonia species are wind dispersed, almost twofifths are animal-dispersed, and over two-fifths are dispersed 

by a combination of rain-wash and epizoochory (de Lange and 

Bouman, 1992). 
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1972. Some Nomenclatural Changes in the Sections of Begonia L. Phyfologia, 24:155-156. 

1974. The Sections of the Genus Begonia. 28 pages. Boston: Northeastern 

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The Species of fhe Begoniaceae. Second edition, iv+ 144 pages. Boston: Northeastern University. 

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Brade, A.C. 

1945. Begonias novas do Brasil, 111, IV. Rodrigeesia, 9(18):17-22,23-34. 

1957. Begoniaceae. In Flora do Itatiaia, I. Rodriguesia, 32(20):151-166. 

1984. Notes on MesoamericanBegonia. Phytologia, 54(7):486-489. 

1985. A Revision of Central American Species of Begonia Section Gireoudia (Begoniaceae). Tulane Sfudies in Zoology and Botany, 25( 1): 

1990. New and Noteworthy Species in Begonia Section Gireoudia (Begoniaceae) from Mexico. Britfonia, 42( l):3846. 

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1974. 

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1949. Beitrage zur Kenntnis der Begoniaceen Sudamerikas. Bofanische 

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1953. Systematische Studien iiber Begoniaceen des Tropischen Siidamerikas, besonders Brasiliens. Bofanische Jahrbucher, 76: 1-102. 

1960. Fam. Begoniaceae, Schiefblattgewachse. In Fritz Encke, editor, 

Parey S Blumengarfnerei, second edition, pages 67-98. Berlin: P. 

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Begoniaceen-Gattungen und Arten. Abhandlungen Konigliche 

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1983. 

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Kuntze, 0. 

1893. Begoniaceae. Revisio Generum Planfarum, 3: 105-106. Leipzig. 

Lange, A. de, and F. Bouman 

1986. Micromorphology of the Seeds in Begonia Section Solananthera A. 

DC. Acfa Botanica Neerlandica, 35(4):489495. 

1992. Seed Micromorphology of the Genus Begonia in Africa: Taxonomic 

and Ecological Implications. Wageningen Agriculfural University 

Papers, 9 l(4): 1-82. 

Mabberley, D.J. 

1989. The Plant-Book. xii+706 pages. Cambridge: Cambridge University 

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Miiller, C. 

1857. Begonia. In W.G. Walpers, Annales Bofanices Sysfematicae, 4:909. 

Panda, Sauris, and J.J.F.E. de Wilde 

1995. Diversity and Taxonomic Value of Stigmatic Surfaces in Begoniaceae: SEM Analysis. Acfa Bofanica Neerlandica, 44(2): 139-1 50. 

1972. Principles of Dispersal in Higher Planfs. Second edition, xi+161 

pages. Berlin: Springer-Verlag. 

Smith, L.B. 

1973. Begonia of Venezuela. Phytologia, 27:209-227. 

Smith, L.B., and B.G. Schubert 

1941. Revision de las especies Argentina del genero Begonia. Darwinima, 5:78-117. 

1946. The Begoniaceae of Colombia. Caldasia, 4(16):1-138; 4(17): 

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1979. Begonia of Ecuador. Phytologia, 44(4):233-256. 

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1984. Notes on Begoniaceae-111. Phytologia, 54(7):465473. 

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1986. Begoniaceae, Part I: Illustrated Key; Part 11: Annotated Species List. 

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Begoniaceae, V. Wageningen Agricultural University Papers, 

Pi$, L. van der 

77-107; 4( 18): 179-209. 

Smith, L.B., and D.C. Wasshausen 

Smith, L.B., D.C. Wasshausen, J. Golding, andC.E. Karegeannes 

Sosef, M.S.M. 

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94(1):1-306. 

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do Estado de Sao Paulo, 2(3):61. 

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Papers, 9 l(4): 1-1 51. 

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Ziesenhenne, R. 

28 
NUMBER 90 29 

PLATE I .-Seeds of sections Trachelocarpus and Solananthera: a, B. herbacea (Lisedecceales s.n.), x 125; b. B. 

herbacea var. ellipficifolia (Ule 4240), x 1 10, c, detail testa, x 500; d, B. solananthera (cult.), x 150; e, B. depauperafa (Campos Goer J40), x 130;J B. lanceolafa (Smifh & Pereira 15343), ~100, g, B. radicans (Luederwaldf 

s.n.), ~80; h, B. infegerrima (Pereira 606), ~95. 
30 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 2.-Seeds of sections Trendelenburgia and Scheidweileria: a, B. fiuticosa (Martins 8380), x 100,J detail 

testa, x490; 6, B. pentaphylla (Muguire C.S. 44596), x 120, c, detail testa, ~480; d, B. luxurians (Hoehne 2370), 

x 130; e, B. digitata (Martinelli & Maas 3271), X 120; g, B. incisoserrata (Hatschbach & Kummran 45532), 

x 170; h, B. parviflora (Killip 7837), ~210. 
NUMBER 90 

PLATE 3.-Seeds of sections Ewuldiu and Enitu: a, B. lobutu (Hutschbuch 30073), x 130; b, B. schur-i (Pulacios-Cuezzo 29301, X 160; c, B. tomentoso (Brude 18572), x 160; d, B. rigidu (ABS Seed Fund), x 190; e, B. convolvuluceu (Schenck 858), X 120;f; B. epibuterium (Scott Mori C.S. 12856), x 140; g, B. fugifoliu (Brude 19144), 

X 120; h, B. glubru var. glubru (Irwin C.S. 54738), x 180, k, detail chalaza, x280;j. B. glubru var. glubru (Luurito 

81 72), x 120. 

31 
32 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 4.-Seeds of section Pritzelia: a, B. dietrichiana (Duarte 378), x 180; b, B. crispula (Boone-Hahn 13), 

detail testa, x5 10; c, B. sanguinea (Bailey & Bailey 706), detail testa, x450, f; seed, x 150; d, B. coccinea 

(Burchell219A), detail testa, ~860, g, seed, x 120; e, B. grisea (St. Hilaire B 2027), x95; h, B. angulata var. 

angulata (Hafschbach 8831), X 120; j, B. ifaguassuensis (Lourfeig 3236), x 150; k, B. dichofoma (Boone-Hahn 

25), ~140; 1, B. acida (cult., Liege), ~180; m, B. paranaensis (Hafschbach 8941), x 110; n, B. olsoniae (Pereira 

307), x 110. 
NUMBER 90 33 

PLATE 5.--Seeds of sections Pritzelia, Philippomartia, Steineria, and Bradea: a, B. bradei (cult.), x 140; 6, B. 

hispida (Bailey & Boiley 710) ~130; c. B. membranacea (Curran I70), x200; d, B. leptophylla (Mo 4331), 

x 170, e, detail chalaza, X44O;f; B. hookerana (Occhioni 4788), x 140, j, detail testa, x760; g, B. arborescens 

var. arborescens (Grisebach s.n.), x 190; h, 8. polyandra (Herb. Hieronymus s.n.), x 140, k, detail testa, x710; 

I, B. oxyphylla (Inh. Vien s.n.), x 190; rn, B. rufosericea (Oswaldo Hanro s.n.), x 160; n, B. bidentata (Peckolt 

79, x 160. 
34 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 6.--Seeds of sections Bradea, Tefrachia. Gaerdfia, Lafisfigma, and Pereira: a, B. dentafiloba (L.B. Smifh 

1935), X 160; b, B. pawifolia (d’Alleizeffe s.n.), x 130; c, B. egregia (Santos Lima s.n.), x 120, g, detail testa, 

~720; d, B. corallina (Boone-Hahn 114), ~125; e, B. maculafa (Maas & Caraufa 3149), xl l5,J detail testa, 

XI 140; h. B. undulafa (Guudichaud 1067), ~140; j, B. aconitifolia (Glariou 13389), x 150; k, B. leafhermaniae 

(Moraes 1056), ~180, n. detail testa, ~560; 1, B. plafanifolia (Hafschbach 46298), x150; m, B. edmundoi 

(Pereira 366), x 140. 
NUMBER 90 

PLATE 7.--Seeds of section Cuspuryu: a, B. urticue (Hurling et ul. 20465), x105, b, detail testa, x340; c, B. 

fuchsiifloru (Scott Hoover 515), detail testa, x620, J; seed, x120; d, B. urticue (Bohlin 979, x 120; e, B. longirostris (Hurling & L. Andersson 11608), x 130; g, B. gumolepis (Killip & A.C. Smith 16037), x 130; h, B.ferrugineu (Lungenheim 3387), ~85; j, B. ferrugineu var. dilututu (Gurciu-Burrigu 12053), xl15, k, detail testa, x370. 

35 
36 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 8.--Seeds of section Cuspatyo: u, B. rrispurhulutu (Tillett 739-585), x 130, 6, detail testa, x770; c, B. 

brevipetab (Steyermurk & Mehlin 109955), detail cuticle, x1690, d, detail testa, x580, g, seed, x 120; e, B. 

trujillensis (Tillett 739-611), x125;j; B. mariue (Goldsmith 163), ~130; h, B. formosissima (Ruiz-Teran & 

Figueirus 9306), x90, j, detail testa, x400; k, B. lipolepis (Goldrmith 167), x 110; 1. B. toledanu (Steyermurk & 

Dunsrerville 100604), x 125; m, B. pectennerviu, seed (Holm-Nielsen 26762), x 125, n. detail testa (HolmNielsen 26438), ~620. 
NUMBER 90 37 

PLATE 9.--Seeds of section Casparya: a, B. colombiana (Schultes & Villarreal 7758), x 120; b, B. killipiana 

(Scott Hoover 27), ~95, c, detail testa, ~280; d, B. trispathulata (Steyermark 103480), detail testa, x550, g, seed, 

x 140; e, B. longirostris (Lug0 4699), x 1 l5;J B. antioquensis (Luteyn 12265), x 140; h, B. hexandra (Core 

ISOO), x 110; j, B. diversistipulata (Giacometto 11) X150; k, B. umbellata (Killip & Hazen 9165), x 105; I, B. 

montana (Funck & Schlim 1044), x 115; m. B. formosissima (Lopez-Figueiras & Dugarte 29409), x 100; n, B. 

raimondi (Raimondi 2982), ~85. 
38 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 10.-Seeds of sections Rossmannia, Hydristyles, and Warburgina: a, B. rossmanniae (Holguer Lug0 S. 

4824), x 170, b, operculum, X440 (Holguer Lug0 S. 4824), c, detail testa, ~510 (Vogelmann C.S. 1297); d, B. santarosensis (s.n.), x 150, e, detail testa, x400;f; aff. B. bridgesii (Dereims s.n.), x 150; g, B. subcaudata (Beck 

9253), ~160; h. B. juntasensis (Moore, Salazar, & Smith 8601), x 180; j, B. unduavensis (Mandon 1089), x 150; 

k, B. undinu (Williams 1566), x 140; I, B. comatu (Beck 12652), x 160. 
NUMBER 90 39 

PLATE 1 1.-Seeds of sections Gobenia, Meionanthera, Lepsia, and Titfelbachia: a, B. maurandiae, seed (Camp 

E 4974), x 130, d, detail chalaza (Andr.e 3315), ~260; b, B. pululahuana (Davis 500) x 115; c, B. secunda (Gentq~ & Shupp 26638), ~150; e, B. holfonis, detail testa (Uribe Uribe 3878), x590, h, seed (Holton 725), x 17O;f; 

B. ynesiae (Mexia 7706), X 115; g, B. sodiroi (Holm-Nielsen & Jeppesen 1276), x 1 10; j, B. foliosa var. ausfralis 

(Matthias & Taylor 5905), ~200; k, B. foliosa var. pufzeysiana (Killip & Smith 1981 7), x 120; 1, B. foliosa var. 

rotundafa (McDougal & Roldan 3540), x 145; m, B. microphylla (Brefeler 4643), x 125; n. B. fuchsioides var. 

fuchsioides (Killip & Smith 20552), x 140. 
40 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 12.-Seeds of section Eupetalum, including former section Huszia: a, B. octopetala (Holm-Nielsen C.S. 

3404), x 190, c, detail testa, x790; 6, B. pastoensis (Lehman 5404) detail cuticle, x3340, d, seed, x 180; e, B. 

erythrocarpa (Wusshausen & Salas If 94), x 180;J B. pleiopetala (Buchtien 653), x 150; g, B. macbrideana 

(Weberbauer 2011), X 130; h, B. geraniifolia (Lourteig 311 7), seed, ~170, k, detail chalaza, x350;j B. geruniifolia (Dowbey s.n.), detail testa, ~690; I, B. cinnabarina (de Michel f6), x 160; m, B. hydrophylloides (Idrobo & 

Evans Schultes 560), ~200; n, B. serotina (Camp E 371 6), X200; 0, B. pearcei (van Veldhuizen 580), x 170. 
NUMBER 90 41 

PLATE 13.--Seeds of sections Eupetalum (including former section Huszia), Apteron. Barya, Pilderia, and Australes: a, B. tumbezensis ( Weberbauer 768M), ~220; b, B. monophylla (Pringle s.n.), x 190; c, B. novogranatae 

(Dawe 272), x 190; d, B. exalata (Sodiro 597), x 190, e, cuticle, x 1970;f; B. boliviensis (Hawkes C.S. 3620), 

detail testa, ~740, g, seed, x 170; h, B. monadelpha (Weberbauer 6714), ~120; j, B. soror (Wurdack 1627), 

x130; k, B. buddleiifolia (Holguer Lug0 S. 5042), X220, n, detail cuticle, ~2380; I, B. tafiensis (Venturi 3093), 

X 140; m, B. micranthera var. micranthera (Petersen & Hjertings.n.), x 160; 0, B. rnicranthera var. foliosa (West 

6216), detail testa, x550. 
42 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 14.-Seeds of sections Urniformia and Gireoudia: a, B. heydei (Haber & Bello 7645), x 11 5, b, detail 

testa, ~870; c,B. plebeja (Taylor I7305), x 170,f; detail cuticle, ~2460; d, B. jenmannii (Maguire & Fanshawe 

23081), x 190; e, B. multinervia (van Veldhuizen 661 ), x 180; g, B. sericoneura (van Veldhuizen 392), detail cuticle, x2710, k, seed, x180; h, B. urophylla (van Veldhuizen 655), x140; j, B. sartorii (Bourgeau 2100), x 150; 1, 

B. crassicaulis (Steyermark s.n.), x 160; m, B. involucrata (Standley 34241), x 190; n, B. conchifolia (Wilbur 

24349), x 160. 
NUMBER 90 43 

PLATE 15.-Seeds of sections Gireoudia. Hexaptera, Dissepbegonia, Podandra, and Weilbachia: a, B. barkeri 

(Smith 690), X160; b, B. cardiocarpa (Utlq 5917), X 180; c, B. heracleijolia (Bourgeau 1583), x190; d, B. omacana (Davidse et al. 26139) x140, e, detail testa, x510 (McVaugh 10266);J B. palmeri (Mexia 219), detail 

testa, ~560, g, seed, ~190; h, B. decandra (Krug & Urban 1121), x 180, j, detail testa, x590; k, B. aridicaulis 

(van Veldhuizen 529), detail testa, ~830, I, seed, x 190; m, B. purpusii (Matuda 5406), x 140; n. B. imperialis 

(DTH 5397), X 145; 0, B. alice-clarkiae (van Veldhuizen 497), x 170. 
44 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 16.-Seeds of section Ruizopuvoniu: u, B. alnifoliu (Mocquerys 1219), x 180, b, detail cuticle, x2620; c, 

B. peruviunu (Sundernun 4378), detail testa, x400J seed, x 190; d, B. corredorunu (Skutch 4733), x260; e, B. 

curpinifoliu (Kappelle & Monge 3635), x 140; g, B. thiemei (Culderon 2258), ~200; h, B. bructeosu (Ellenberg 

815), detail cuticle, x 1640, k, seed, x I80;j. B. udisylvestris (Burger & Srolze 5250), detail testa, x490, m, seed, 

x 115; I, B. seemunniunu (Seemunn 1661), ~200; n, B. suprufmtigiutu (Weberbuuer 7907), x 145; 0, B. cuutrecusiunu (Forrero-Jurumillo 2403), x 180. 
NUMBER 90 45 

PLATE 17.--Seeds of sections Ruizopavonia and Dorafometra: a, B. estrellensis, x 130 (Zamora C.S. 512), b. 

x 145 (Liesner 1023); c, B. steyermarkii (Cowan & Soderstrom 1841), x200; d, B. waNichiana (Stanford C.S. 

972), detail cuticle, x2610, g, seed, x 180; e, B. prieurii(1rwin C.S. 48113), detail testa, x420,f; seed, x200; h, B. 

filipes (Thiebaut 41), ~240; j, B. humilis (Egger 1404), x210; k, B. tonduzii (Grayum 8132), x220; I, B. hirsuta 

(Herb. Splitgerberianum), x 190; m. B. hirtella (Lourteig 2308), x2 10. 
46 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 18.-Seeds of section Begonia: a, B. obliqua (Duss 973), x 170, d, detail testa, x 1890; b, B. rofundfolia 

(cult., Liege), X 180; c, B. glandulfera (Van Sfeenis 20304), ~200; e, B. plumieri var. barahonensis (Miguel 

Fuerfes 432), detail testa, x 11 50, h, seed, x 160;f; B. odorata (Morton 5066), x 160; g, B. refusa (Stoffers 3116), 

XZOO; j, B. guaduensis (Maas & Westra 3877), ~150; k, B. cubensis (Ziesenhenne s.n.), x160; I, B. cyafophora 

(Mexia 8128), X 180; m, B. alfoperuviana (Weddell 4556), x 170; n, B. organensis (Sucre C.S. SOOS), x 130. 
NUMBER 90 47 

PLATE 19.-Seeds of section Begonia: a, B. cucullata var. cucullata, x 125 (Irwin C.S. 1996l), b. x 125 (Bartletf 

21359), c. detail cuticle, x 1730 (Barflett 21359); d, B. cucullata var. arenosicola (Pedersen 10232), x 190; e, B. 

fischeri var.fischeri (Sfeyermark & Rube 96605), x 100,f; detail testa, x470; g, B. alchemilloides (Irwin C.S. 

34478), X 190; h. B. balansae (Balansa 3281), x 150; j, B. descoleana (Hatschbach 9944), x160; k, B.fischeri 

var. klugii (Klug 3389), x 115; 1, B. per-dusenii (Smith, Klein. & Schnorrenberger 11728), ~190; m, B. subvillosa var. leptofricha (Fiebrig 5354), x 180. 
48 SMITHSONIAN CONTRIBUTIONS TO BOTANY 

PLATE 2O.--Seeds of section Knesebeckia: a, B. incarnafa (Liebmann I77), x 180, d, detail testa, x610; b, B. 

kellermannii (Ziesenhenne s.n.), X 140; c, B. peltata (Boom 14288), x 160; e, B. gracilis (Pringle 11452), detail 

testa, ~970, h, seed, x2OO;f; B. boissieri (van Veldhuizen 747), x 180; g, B. ludwigii (van Veldhuizen 618), x 140; 

j, B. sandfii (Ziesenhenne s.n.), X 170; k, B. angustiloba (Diguef s.n.), x 190; I, B. falciloba (Bourgeau 649), 

x 170; m, B. ignea (Piffier & Durand 1299), x 140; n, B. unifora (Roybal647), x 160. 
NUMBER 90 49 

PLATE 21 .--Seeds of sections Knesebeckia and Donaldia: a, B. oellgaardii (Baker 6396), x 190; b. B. rnaynensis 

(Prance C.S. 7409), ~220, c, detail testa, ~780; d, B. olbia (van Veldhuizen 434), detail testa, x610, g, seed, 

X 140; e, B. wollnyi (van Veldhuizen 439, x24O;J; B. dichroa (Ziesenhenne s.n.), x 140; h, B. ulrnifolia (Hekking 

1428), ~210, k, detail chalaza, x420; j, B. dasycarpa (Glaziou 15388), detail testa, x760, I, seed, x 160; m, B. 

chaetocarpa var. chaetocarpa (Kuntze s.n.), ~210; n, B. chaetocarpa var. glabrijlora (Rusby 690), x 180; 0, B. 

bangii (Bang 406), x 180.