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Seed Micromorphology of 
Neotropical Begonias 




A. DE LANGE 

and 
F. BOUMAN 



'V 



SMITHSONIAN CONTRIBUTIONS TO BOTANY • NUMBER 90 



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SMITHSONIAN CONTRIBUTIONS TO BOTANY • NUMBER 90 



Seed Micromorphology of 
Neotropical Begonias 

A. de Lange 
and F. Bouman 



SEP I 0 1999 




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 sec- 
tions, were studied using scanning electron microscopy. The seeds show an appreciable diver- 
sity 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 Begonia filipes to 1450 ]xm 
in B. fruticosa; most seeds have a length between 300 ]im 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 chalazal 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 Trachelocar- 
pus 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. Serjes 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. 
p. cm. — (Smithsonian contributions to botany ; no. 90) 

Includes bibliographical references. 

1. Begonias — Seeds — Morphology. 2. Scanning electron microscopy. 
\. Bouman, F. II. Title. III. Series. 
QK1.S2747 no. 90 
[QK495.B4] 
580 s— dc21 

[583'.627I467] 99-30195 

GIF 



@ The paper used in this publication meets the minimum requirements of the American 
National Standard for Permanence of Paper for Printed Library Materials Z39.48 — 1984. 



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 Scheidweileria {K\otz?,c\\) 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 7e/rac/z/a Brade 8 

1.11. Section Gaerdtia (Klotzsch) A. DC 8 

1.12. Secixon Latistigma A. DC 8 

1.13. Section Perara 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 antioquensis 11 

Begonia hexandra 11 

Begonia diversistipulata Group 12 

Ungrouped Species 12 

2.2. Section Rossmannia (Klotzsch) A. DC 12 

2.3. Section Hydristyles A. DC 12 

2.4. Section WarburginaO. Kuntxe 13 

2.5. Section Gobenia A. DC 13 

2.6. Section Meionanthera A. DC 14 

2.7. Sections Le/j.s/o (Klotzsch) A. DC. and r/Z/c/^ac/i/o (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 ^aryo (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 /iw.y/ra/e'^ Smith & Schubert 16 

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

Regions 16 

4. 1 . Section Urniformia Houghton ex Ziesenhenne 17 

4.2. Section G/z-eowt/Za (Klotzsch) A. DC 17 

4.3. Section //ejcop/era Ziesenhenne 17 

4.4. Section Dissepbegonia Ziesenhenne 18 

iii 



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. SqcXxow Ruizopavonia A. T)C 19 

6. Sections with a Wide Neotropical Distribution 20 

6. 1 . Section Doratometra (Klotzsch) A. DC 20 

6.2. Section Begonia Baranov & Barkley 20 

Begonia obi iqua Group 21 

Begonia cucullata — Begonia fischeri Group 21 

Ungrouped Species 22 

6.3. Section Knesebeckia (Klotzsch) A. DC 22 

6.4. Section Donaldia (Klotzsch) A. DC 23 

Discussion 23 

Seed Morphology 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 



Seed Micromorphology of 
Neotropical Begonias 



A. de Lange 
and F. Bouman 



Introduction 

The genus Begonia L. represents one of the larger genera of 
flowering plants and has a complicated taxonomic history. Ge- 
neric concepts in the family Begoniaceae have changed much; 
about 50 genus names have been put into synonymy with Be- 
gonia. According to current opinions, the family comprises 
only the genera Begonia, Hillebrandia, and Symbegonia, al- 
though 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. (1986) and Golding ( 1992), Bego- 
nia 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 lev- 
el by the presence of a transverse ring of so-called collar cells. 
These cells are usually elongated and border the micropylar-hi- 
lar part of the seed. During germination, this part separates 
along preformed rupture lines and is lifted off like a seed lid or 
operculum (Figure 1), 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 com- 
mon "ordinary" Begonia seeds mostly measure between 300 
pm and 600 |am long. As far as is known, the extremes are 
found among the African begonias: the smallest seeds are re- 
corded 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, Wash- 
ington, D.C., 20560-0166. 

Reviewers: K. Burt-Utley, Department of Biological Sciences, Univer- 
sity of New Orleans, New Orleans, Louisiana: D.C. Wasshausen, 
Department of Botany, Smithsonian Institution, Washington, D. C. 




hi I um mi cropyl e 



opercul um 



col I ar eel I 



other testa eel 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 anat- 
omy (Sosef, 1994)), sections have been revised and intersec- 
tional relations have become clearer. A comparative scanning- 
electron-microscopy (SEM) study proved seed micromorphol- 
ogy 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 al- 
ternative ways. Animals may eat the fleshy, often colored 
fruits; seeds also may be dispersed by mud on the legs of pass- 
ing animals or by rain wash (de Lange and Bouman, 1992). 

The taxonomy of the Neotropical begonias is far from set- 
tled. During his long botanical career, Lyman B. Smith, in co- 
operation 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 (1985) on the Central American and Mex- 
ican species of section Gireoudia. Because of the lack of a re- 
cent, 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 publica- 
tions on newly described species. 

In the Neotropics, about 600 Begonia species are recognized. 
According to Baranov and Barkley (1974), these are arranged 
in 47 sections; however, four of these sections, Auriformia, 
Irmscheria. Quadriperigonia, and Saueria. have since been 
eliminated due to synonymy. The monotypic section Dasy- 
styles is of uncertain origin and is based on cultivated speci- 
mens. 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. Thir- 
ty-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 
(1946) discussed the use of placental form as the basis for divi- 
sion into sections but in subsequent publications ignored sec- 
tions altogether. In her description of the begonias of Madagas- 
car, Keraudren-Aymonin (1983) also renounced classifying 
species into previously recognized sections. The studies on Af- 
rican begonias, however, clearly demonstrated the sensibleness 
and usefulness of a sectional division. Sosef (1994:1 1) 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 be- 
gonias 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 valu- 
able data to the descriptions and relationships of the sections. 
We thank the late Lyman B. Smith (National Museum of Natu- 
ral History (NMNH), Smithsonian Institution, Washington, 
D.C.) for his indications of taxonomic problems on sectional 
delimitation. Dieter Wasshausen (NMNH) is gratefully ac- 
knowledged for his interest and hospitality during the first au- 
thor's visit to the United States National Herbarium. 

We thank J.J.F.E. de Wilde and M.S.M. Sosef of the Depart- 
ment 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 sever- 
al thousands of SEM photographs, and W. Takkenberg provid- 
ed technical assistance with SEM (Hugo de Vries-Laboratory, 
Amsterdam). The Netherlands Organization for Scientific Re- 
search 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 herbar- 
ia: AAU, AMD, B, COL, CR, G, GENT, K, L, MO, P, PDA, 
PRE, RB, SP, U, US, and WAG. Moreover, seeds were re- 
ceived 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. Ziesen- 
henne (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 num- 
ber 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 ISI 
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 usual- 
ly six seeds. The seed width was measured at the widest appar- 
ent point. All mentioned mean sizes are arithmetically deter- 
mined. 



NUMBER 90 



3 



Description of Seeds of Neotropical Begonias 

In the descriptions of Neotropical Begonia seeds, we empha- 
size those sections with a characteristic seed structure that 
sometimes can be related to special growth forms or to meth- 
ods of seed dispersal. Sections with seeds conforming to the or- 
dinary seed type are dealt with more briefly. Although varia- 
tion in seed micromorphology between sections can provide 
taxonomic information, in view of the issue of correct identifi- 
cations and the sometimes complicated nomenclature, detailed 
comparative studies are most valuable when done in close co- 
operation 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, Trendelen- 
burgia) share a unique seed structure that is characteristic at the 
sectional level. Seeds of the species within each of these sec- 
tions can be distinctly discerned from those of all other sec- 
tions. Of nine remaining sections, the seeds of all or most spe- 
cies 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 speci- 
men, probably related to section Ewaldia (Warburg, 1 894). 

1.1. Section Trachelocarpus A. DC. 

Plate \a-c,e,f 

This taxon was first described by Klotzsch as the genus Tra- 
chelanthus in 1855. C. Mueller (1857) changed the name to 
Trachelocarpus, and subsequently A. De Candolle (1859) re- 
duced its status to sectional level. The section now comprises 
six species, restricted to Brazil. The taxonomically correct sec- 
tion type (Doorenbos et al., 1998) is Begonia depauperata 
Schott (=5. 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 ]im in length, 305-330 pm in width, mean 800 ]im x 
320 ]im, length: width ratio 2.5. Collar cells relatively short. 



175-280 \im in length, mean 205 pm, number in seed circum- 
ference 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, com- 
posed of many irregularly arranged small cells. 

Seed Micromorphology: Anticlinal boundaries straight or 
sometimes sunken. Cuticle with net-like structure of upright or 
folded-over pleats. Cuticular striae usually occurring only lo- 
cally, 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 \a-c,f). — Seed Structure 
and Micromorphology: Begonia herbacea Vellozo and B. 
lanceolata Vellozo (syn. B. attenuata A. DC.) have seed struc- 
tures that resemble those of B. depauperata in general mor- 
phology and cuticular structure. Seeds of B. herbacea have a 
mean size of 850 pm x 370 pm. Seeds of B. herbacea var. el- 
lipticifolia Irmscher are slightly longer, 855-935 pm (mean 
910 pm X 370 pm), have a length: 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); Lisedec- 

ceales s.n. (B). 
B. lanceolata, BRAZIL: LB. Smith & Pereira 15343 (US). 

1.2. Section Solananthera A. DC. 

Plate Id.g.h 

The section Solananthera was established by A. De Candolle 
in 1859. It contains three species restricted to Brazil. The spe- 
cies are epiphytic, climbing subshrubs. The section is charac- 
terized by the presence of porate anthers and two-divided pla- 
centas, the lobes of which cling to each other. The seeds of the 
three species have been described in detail (de Lange and Bou- 
man, 1986). 

Type Species. — Begonia solananthera A. DC. (Plate \d). 

Seed Structure: Seeds narrowly elliptic to narrowly obo- 
vate, mostly straight, sometimes J- or C-shaped. Mean seed 
size 755 pm x 145 pm, length: 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 undulat- 
ed. Outer cell walls convex. Operculum obtuse, funnel-like, 
with sunken hilum. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar pattern consisting of long linear undulated striae. 

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

Other Species Observed (Plate \g.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 \xm 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 re- 
semble those of B. fruticosa of section Trendelenburgia. The 
periclinal walls of the testa cells are collapsed, with the excep- 
tion of those at the chalaza of B. radicans. 

Specimens Examined: 
B. integerrima var. integerrima, BRAZIL: E. Pereira 606 (RB). 
B. radicans, BRAZIL: H. Luederwaldt s.n. (SP); A. P. Duarte 
ii77 (RB). 

1.3. Section Trendelenburgia (Klotzsch) A. DC. 

Plate la.f 

The taxon Trendelenburgia was first described by Klotzsch 
as a genus in 1855 on the basis of one of the early Begonia col- 
lections by Ludwig Riedel in 1839. A. De CandoUe (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. Begonia fruticosa oc- 
curs in Argentina and southern Brazil. 

Type Species. — Begonia fruticosa A. DC. (Plate 2a,/). 

Seed Structure: Seeds narrowly ellipsoid, extended micro- 
pylar and chalazal 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 J- 
or slightly S-shaped. Seed length 1310-1540 pm, width 
160-200 pm, mean 1450 pm x 180 pm, length: width ratio 8.1 
(slenderest seeds ever encountered in Begonia). Seeds of above 
described collection (Martins 8380) the biggest. Seeds of col- 
lections Herb. Brasil 1717, Kummrow 1636, a*.d Herb. Brasil 
850 with mean lengths of 1060 pm, 1005 pm, and 965 pm, re- 
spectively, and length: width ratios of 7.3, 5.4, and 6.3, respec- 
tively. 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 undu- 
lated walls. Cells of operculum adjacent to collar elongated. 
Hilum sunken. 

Seed Micromorphology : Anticlinal boundaries of opercu- 
lum and chalaza sunken, those of central part of seed somewhat 
less so. Cuticle smooth, locally with faint, striate ornamenta- 
tion, cuticle of central part of seed reflecting underlying pits. 
Larger pits present at bases of anticlinal walls. 

Specimens Examined: 
B. fruticosa, BRAZIL: R. Kummrow 1636 (MO); H.F. Martins 

8380 (US); H. Schenck, Herb. Brazil 850, 1717(B). 



1 .4. Section Scheidweileria (Klotzsch) A. DC. 

Plate lb-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 character- 
ized by five tepals, stigmas as helical bands with three turns, 
and undivided placentas. No seeds were available for B. semi- 
digitata Brade. 

Most species of the section are limited to Brazil, but B. 
parviflora Poeppig & Endler has a wider distribution, extend- 
ing 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, length: 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 opercu- 
lum abrupt. Operculum nipple-shaped, with collapsed cells. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar pattern variable, that of collar cells mainly linear, that of re- 
maining testa cells with shorter linear, undulated, or short zig- 
zag 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. 
parviflora are 270-350 pm in length, 155-180 pm in width, 
with a mean of 3 1 5 pm x 1 70 pm, and have a length : width ra- 
tio 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 luxurians 
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 
length: width ratio of 3.3. The collection de Barros 1139 has 
smaller seeds, with a mean of 485 pm x 195 pm. Begonia digi- 
tata 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 



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 |im 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 an- 
ticlinal walls except B. parviflora, in which all specimens lo- 
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); LB. Smith cs. 6691 (US). 
B. incisoserrata, BRAZIL: A.C. Brade 20096 (B); G. Hatsch- 

bach & R. Kummran 45532 (US). 
B. luxurians var. luxurians, BRAZIL: D. de Barros 1139 (B); 

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

8045 (US). 

B. parviflora, COLOMBIA: Ed. Andre K 284 (K); J. Cuatrecasas 
11311 (US); Killip 7837 (US). ECUADOR: Holguer Lugo S 
1808 (MO). 

1.5. Section Ewaldia A. DC. 

Plate "ia-d 

This taxon was described by Klotzsch (1855) 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 num- 
ber 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, 
565-650 pm in length, 195-215 pm in width, mean 605-200 
pm, length: 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 length: width ratio of 1.9. Collar cells 
elongate, 1 15-210 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. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar pattern coarse, that of chalazal cells with short linear or 
short undulated striae. Locally, patches with less pronounced, 
denser pattern. 

Specimens Examined: 
B. lobata, BRAZIL: G.L. Esteves c.s. CFCR 6028 (SP); G. 

Hatschbach 30073 (US), 36564 (MO). 
B. aff. lobata, BRAZIL: P.J.M. Maas c.s. 3318 (U). 



Other Species Observed (Plate 3b-d). — Seed Structure 
and Micromorphology: The seeds of B. rigida Linden ex Re- 
gel, 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. scharffii), and 485 x 210 pm {B. 
tomentosa), with length: width ratios of 2.1, 2.2, and 2.3, re- 
spectively. 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. 

Specimens Examined: 
B. rigida, BRAZIL: ABS Seed Fund (1983). 
B. scharffii, BRAZIL: Palacios-Cuezzo 2930 (US). 
B. tomentosa var. tomentosa, BRAZIL: A.C. Brade 18572 (US). 

1 .6. Section Enita Brade 
Plate 3e,/-^ 

The species now constituting section Enita have a rather 
complicated taxonomic history. Klotzsch (1855) 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 (1894) merged Wageneria with the large 
section Pritzelia, and this opinion was shared by Irmscher 
(1925). Brade (1945) established Enita as a subsection and lat- 
er 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 spe- 
cies of section Enita deviate from those of section Pritzelia by 
having stamens with filaments slightly united below and an- 
thers 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, 180-215 pm in 
width, mean 675 pm x 195 pm, length:width ratio 3.4. Collar 
cells elongate, 130^75 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. Chalazal 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. 

Seed Micromorphology: 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 or- 
namentation. 

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, pi. 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 J 2856), which 
has a more tapering, often somewhat asymmetric chalaza. Seed 
size in B. epibaterium tends to be a little smaller, as in B. con- 
volvulacea. The mean seed size varies from 495 pm x 1 70 pm 
in B. epibaterium (Dos Santos 3408) to 660 pm x 150 pm in B. 
glabra (Laurito 8172). The length: width ratio in section Enita 
varies between 2.9 and 4.4. In all specimens observed the anti- 
clinal walls may be undulated; however, some variation exists 
in the presence and extent of the undulations. 

Remarks: The seeds of the different collections of the 
widespread species B. glabra vary in respect to the above-men- 
tioned characters. The specimens from Surinam differ by hav- 
ing conspicuous chalaza with inflated cells, which make the 
chalaza even broader than the central part of the seed. The cu- 
ticular 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 col- 
lar-cell length to seed length is 3.4. 

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



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

(US); Scott Mori & Forbes Benton 12856 (US). 
B. fagifolia, BRAZIL: Brade 19144 (B); Gaudichaud 1060 (?). 
B. glabra var. amplifolia, COLOMBIA: E.P. Killip 7722 (K). 
B. glabra var. cordifolia, CULTIVATED: van Veldhuizen 370 

(WAG). 

B. glabra var. glabra, COLOMBIA: T.A. Sprague 403 (K). 
COSTA RICA: Gomez Laurito 8172 (CR). CUBA: C. Wright 
2627 (?). ECUADOR: Grubb c.s. 1199 (K). GUYANA: G. Cre- 
mers 81 (?). SURINAM: Indigen 270 (U); H.S. Irwin c.s. 
54738, 54818 (V). 

1.7. Section Pritzelia (Klotzsch) A. DC. 
Plates 4, 5a, b 

The section is characterized by male flowers with four te- 
pals, 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 ob- 
served 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 nar- 
rowly ellipsoid. The mean seed size of the section type, B. 
dietrichiana Irmscher, is 350 pm x 195 pm, with a 
length: width ratio of 1.8. Within the section the mean seed 
length varies from 310 pm in B. acida Vellozo to 620 pm in B. 
angulata Vellozo var. serrana Brade, and the length: width ra- 
tio 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. 

Seed Micromorphology: The anticlinal boundaries are flat 
except for those of B. grisea A. DC. and B. itaguassuensis 
Brade, which have sunken and locally sunken anticlinals, re- 
spectively. The majority of the seeds have a fine, dense cuticu- 
lar pattern of mainly short linear striae, more zigzag in B. epip- 
sila Brade and B. paranaensis. In B. grisea the cuticle is almost 
without ornamentation. Five species deviate in cuticular sculp- 
ture. 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 pro- 
nounced, 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 oth- 
er observed Pritzelia species by having anticlinal walls that are 



NUMBER 90 



7 



more thickened and elevated, are straight and form a distinct 
polygonal pattern at the outside, and are undulated, with pock- 
ets at their bases. 

Begonia grisea and B. paranaensis resemble each other in 
shape and testal pattern. The seeds of B. bradei Irmscher, B. 
crispula Brade, B. dietrichiana, and B. olsoniae Smith & Schu- 
bert also resemble each other in some respects. The seeds oi B. 
itupavensis Brade most resemble those of B. hookerana Gard- 
ner {Occhioni 4788) of section Steineria. 

Remarks: 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 Pritze- 
lia 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 Pritze- 
lia from Brazil, e.g., B. angulata. 

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

bot. Liege. 

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

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: Burchell 219A (P); cult., Ziesenhenne s.n. 
B. crispula, BRAZIL: cult., Boone-Hahn 13 (WAG). 
B. dichotoma, COLOMBIA: cult., Boone-Hahn 25 (WAG, as B. 
sulcata). 

B. dietrichiana, BRAZIL: A.P. Duarte 378 (US). 
B. epipsila, BRAZIL: cult., Boone-Hahn 27 (WAG). 
B. grisea, BRAZIL: St. Hilaire B 2027 (P); HS. Irwin c.s. 27654 
(MO). 

B. hispida var. hispida, BRAZIL: Bailey & Bailey 710 (L); Vau- 
thier 542 (P). 

B huegelii (Klotzsch) ex A. DC, BRAZIL: Altamira & Wolter 

;;(U). 

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

B. itupavensis, BRAZIL: Hatschbach 11713 (U). 

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

Pereira 307 (RB, as B. vellozoana Brade, paratype). 
B. paranaensis, BRAZIL: Hatschbach 8941 (L). 
B. petasitifolia Brade, BRAZIL: cult., van Veldhuizen 997 

(WAG). 

B. reniformis Dryander, BRAZIL: Luederwaldt & Fonseca 

18031 (B); Ynes Mexia 5148 (P). 
B. sanguinea, BRAZIL: Bailey & Bailey 706 (L). 

1.8. Section Philippomartia A. DC. 

Plate 5c-e 

According to Irmscher (1953), 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. lep- 
tophylla 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 nip- 
ple-shaped. 

Seed Micromorphology: The cuticular pattern is fine and 
dense; the striae are short linear in B. leptophylla and are zig- 
zag in B. membranacea. 

Specimens Examined: 
B. leptophylla, BRAZIL: A. Mo 4331 (MO). 
B. membranacea. BRAZIL: HM. Curran 170 (US); Ex herb, 
horti Petropolitani Brasilia Castelnuovo (K). 

1.9. Sections Steineria (Klotzsch) A. DC. and Bradea Toledo 
Plates 5/-«. ba.b 

Section Bradea was separated from section Steinera by Tole- 
do 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 distin- 
guished 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. opuliflora Putzeys 
from the former New Granada, which is based on a drawing of 
a horticultural specimen. 

Type Species, Section Steineria.^Begonia hookerana 
Gardner (Plate 5/ j ). 

Seed Structure: Seeds narrowly ellipsoid to ellipsoid. 
Mean seed size 465 pm x 180 pm, length: width ratio 2.6. Col- 
lar cells elongated, other testa cells polygonal, with straight or 
slightly curved anticlinal walls. Operculum nipple-shaped. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar pattern consisting of mainly short linear striae. Seeds of col- 
lection Burchell 2539 somewhat smaller, with locally undulat- 
ed anticlinal walls and fainter cuticular pattern. 

Specimens Examined: 
B. hookerana, BRAZIL: Burchell 2539 (K); P. Occhioni 4788 
(US). 

Other Species Observed, Section Steineria (Plate 
Sg,l). — The seeds of B. arborescens Raddi var. arborescens 
and B. oxyphylla A. DC. resemble those of B. hookerana, espe- 
cially collection Burchell 2539. Their mean seed sizes vary be- 
tween 330 pm and 415 pm. They all show locally undulated 
anticlinal walls with pockets at their bases and thin outer peri- 
clinal walls reflecting many small pits. The cuticular pattern of 



8 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 



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

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

Grisebach s.n. (K); J. Miers 3291 (K). 
B. arborescens var. confertiflora, BRAZIL: Gardner 602 (K, 

type). 

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

Type Species, Section Bradea. — Begonia rufosericea To- 
ledo (Plate 5w). 

Seed Structure and Micromorphology: Seeds closely re- 
sembling those of (especially) B. arborescens in general aspect 
and in above-mentioned characters, except for less-pronounced 
undulation of anticlinal walls. 

Specimens Examined: 
B. rufosericea, BRAZIL: Oswaldo Hanro s.n. (B); cult., van 
Veldhuizen 496 (WAG). 

Other Species Observed, Section Bradea (Plates 5h.k,n, 
6a, b). — Some other seed collections of section Bradea ob- 
served, 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. 

Specimens Examined: 
B. bidentata var. bidentata, BRAZIL: A. Glaziou J 1873 (K); G. 

Peckolt 75 (B); E. Pereira 287 (B); Riedel s.n. (U). 
B. dentatiloba, BRAZIL: L.B. Smith 1935 (K). 
B. parvifolia, BRAZIL: d'Alleizette s.n. (L); A. Glaziou 15388 

(K); Brasilia Schott s.n. (B). 
B. polyandra, BRAZIL: Herb. Hieronymus s.n. (B, type). 

1.10. Section TefracAm 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 charac- 
terized 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 |im in length, 
250-300 |im in width, mean 530 pm x 275 ]im, length: width 
ratio 1.9. Collar cells 155-230 ]im 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 col- 
lar. Operculum broadly nipple-shaped. 



Seed Micromorphology: Anticlinal boundaries straight. 
Cuticular pattern consisting of long linear and long zigzag stri- 
ae, the latter locally more pronounced. 

Remarks: Seeds resemble those of B. itaguassuensis of 
section Pritzelia in the more thickened, straight, and elevated 
anticlinal walls. 

Specimens Examined: 
B. egregia, BRAZIL: J. Santos Lima s.n. (US, as B. quadrilocu- 
laris Brade, isotype); cult., Boone-Hahn 1 (WAG). 

1.11. Section Gaerdtia (Klotzsch) A. DC. 

Plate 6d-f,h 

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. coral Una Carriere, and B. undulata Schott, 
were observed. 

Type Species. — Begonia maculata (Plate 6e,f), the seeds of 
which are to some extent characteristic and deviate in size and 
shape from the two other species observed. 

Seed Structure: Seeds elliptic, sometimes narrowly elliptic. 
Mean seed size 565 pm x 240 pm, length: width ratio 2.4. Col- 
lar cells relatively long, mean length 290 pm. Ratio of collar- 
cell 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 Micro- 
morphology: The seeds of B. corallina and B. undulata are 
smaller, with a mean seed length of 495 pm and 460 pm, re- 
spectively. 

Specimens Examined: 
B. corallina, CULTIVATED: Boone-Hahn 114 (WAG). 
B. undulata, BRAZIL: Gaudichaud 1067 {?); cult, Hort. Bogor- 
iensis 6071 AB (L). 

1.12. Section Latistigma 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. leatherma- 
niae 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: Cuticular pattern fine and very 
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. leath- 
ermaniae closely resemble those of B. aconitifolia, differing 
mainly by their somewhat smaller size. 

Specimens Examined: 
B. leathermaniae, BOLIVIA: O. Kuntze s.n. (B); M. Moraes 1056 

(US). 

B. platanifolia var. platanifolia, BRAZIL: Creagh s.n. (B); G. 
Hatschbach 46298 (US). 

1.13. Section Pereira Brade 
Plate 6m 

This monotypic section is characterized by two-lobate broad 
stigmata that are almost kidney-shaped and cymatium-like. 

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, length: width ratio 2.0. Anticli- 
nal walls straight and relatively thin. Cuticular pattern consist- 
ing of short linear to short zigzag striae. 

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

2. Sections Mainly Confined to the Andean 
and guianan regions 

Of the 12 Andean sections, five (Casparya, Gobenia, Hydri- 
styles, 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 (1855), 
A. De CandoUe (1864) extended it by including in it Klotzsch's 
genera Isopteryx, Sassea, and Stibadotheca and his newly de- 
scribed sections Aetheopteryx and Andiphila. Warburg (1894) 
reduced the genus Casparya to sectional level and reduced De 
CandoUe's sections to subsections, actions that were later ac- 
cepted by Irmscher (1925). Moreover, he inserted Isopteryx in 
Andiphila. 

Smith and Schubert (1955) expressed the opion that the sym- 
petalous character upon which the genera Begoniella Oliver 
and Semibegoniella C. DC. were based no longer was tenable. 
Consequently, the two species constituting genus Semibego- 
niella were placed into synonymy with Begonia grewiifolia (A. 
DC.) Warburg and so transferred to section Casparya. Smith 



and Schubert ( 1 955) 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 P. (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 
chalazal end. Length 695-780 pm, width 370-390 pm, mean 
745 lam x 385 \im. 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 collar- 
cell length to seed length 1 :5.7. Longitudinal walls of collar 
undulated over entire length. Other testa cells polygonal, most- 
ly not arranged in distinct rows. Anticlinal walls strongly undu- 
lated. 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. 

Remarks: The 10 samples of B. urticae studied, the most 
common and most widely distributed species of section Cas- 
parya, 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 Mar- 
ling 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 length: width ratio varies from 1.7 {Dtyander 1694 ) 
to 2.0 (Schultes & Villarreal 7786 ). The collections Bohlin 975 
(originally described as B. urticae var. retusa Smith & Schu- 
bert), Cuatrecasas 23515, de Escobar c.s. 8521 (originally de- 
scribed 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 Cuatre- 
casas 23515 and Scott Hoover 442 are 585 pm x 320 pm and 
605 pm X 315 pm, respectively. In both collections, however, 
the cuticle has undulated striae of normal thickness. The collec- 
tion 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. 

Specimens Examined: 
B. species, ECUADOR: van der Werff & Palacios 9135 (MO); 

Scott Hoover & Wormley 1822 (MO). 



10 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 



B. urticae, COLOMBIA: M.A. Bonpland s.n. (P); F. Bouman s.n. 
(AMD); Cuatrecasas 23515 (US); E. Dryander 1694 (US); 
de Escobar, Velasquez, & Marulanda 8521 (US); W. Irally 
192 (K); W. Scott Hoover 442 (US); Schultes & Villarreal 
7786 (US). ECUADOR: J.E. & M. Bohlin 975 (US); Marling 
et al. 20465 (US). 

Other Species Observed (Plate lc,e-g). — Seed Structure 
and Micromorphology: The seeds of B. fuchsiiflora (A. DC.) 

A. Baranov & F.A. Barkley, B. gamolepis L.B. Smith & B.G. 
Schubert, B. longirostris Bentham (Marling & L. Andersson 
1 1608), and B. species (Scott Moover & Wormley 1 771) resem- 
ble 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 ]xm in B. 
gamolepis to 630 pm x 375 jam in B. fuchsiiflora. All collec- 
tions have a cuticle with mainly undulated striae of normal 
thickness except for collection Scott Moover & Wormley 1771, 
which has a faint double structure. 

Specimens Examined: 

B. fuchsiiflora, ECUADOR: M.T. Madison 6854 (US); W. Scott 
Moover 515 (MO). 

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

Killip & A.C. Smith 16037 (B). 
B. longirostris, ECUADOR: Marling & L. Andersson 11608 

(US). 

B. species, ECUADOR: Scott Moover & Wormley 1771 (MO). 
Begonia ferruginea Group 

Begonia ferruginea LINNAEUS F. (Plate Ih-k). — Seed 
Structure: Seeds narrowly obovate to obtriangular, micropy- 
lar 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 circum- 
ference 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 po- 
lygonal. Operculum nipple-shaped. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar ornamentation conspicuous, more or less plicate, composed 
of long, undulated foldings forming loose structure. Locally, 
patches with long, parallel striae. 

Remarks: 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 710 pm x 345 pm in collec- 
tion Steyermark & Dunsterville 100784, with length: width ra- 
tios 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 cuticu- 



lar plicas and foldings are long and are undulated or somewhat 
zigzag. 

Specimens Examined: 
B. ferruginea var. dilatata, COLOMBIA: M. Garcia-Barriga 
12053 (US). 

B. ferruginea var. ferruginea, COLOMBIA: Grubb, Curry, & 
Fernandez-Perez 534 (US); J.M. Langenheim 3387 (US); 
Steyermark & Dunsterville 100784 (US). 

B. species, COLOMBIA: F.A. Barkley 38cl20 (US). 

Begonia trispathulata Group 

Begonia trispathulata (A. DC.) WARBURG (Plate Sa,b). — 
Seed Structure: Seeds ellipsoid, micropylar end flattened, 
seeds 420-470 pm in length, 280-285 pm in width, mean 445 
pm X 280 pm, length: width ratio 1.6. Seeds of collection L. 
Goldsmith 169 shorter than those of above-described collection 
(SS. 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. Opercu- 
lum nipple-shaped. 

Seed Micromorphology: 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 labyrinth- 
like structure. 

Specimens Examined: 
B. trispathulata, VENEZUELA: L. Goldsmith 169 (VT); A^. Ram- 
irez 349 (MO); S S Tillett 739-585 (P). 

Other Species Observed (Plate 8c-/). — 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 dis- 
tinct 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 star- 
shaped, whereas in B. mariae they are mainly star-shaped. The 
star-shaped ornaments often show a central depression. 

The seeds of B. lipolepis L.B. Smith differ in some charac- 
ters. 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 length: 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 star- 
shaped 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 dis- 
tinctly 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 undu- 
lated. The double structure is composed of relatively dense, 



NUMBER 90 



11 



mainly short zigzag elevations that obscure the underlying 
granular pattern. 

Specimens Examined: 
B. brevipetala var. brevipetala, VENEZUELA: F.J. Breteler 

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

109955 (U). 

B. formosissima. VENEZUELA: L. Goldsmith 166 (VT); Ruiz- 

Teran & 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 

20270 (B). VENEZUELA: Steyermark & Dunsterville 100604 

(K). 

B. tnijillensis, VENEZUELA: L. Goldsmith 168 (VT); S.S. Tillett 
739-611 (US). 

Begonia pectennervia Group 

Begonia pectennervia L.B. SMITH & Wasshausen (Plate 
Sm,n). — Seed Structure: Seeds ellipsoid, 535-590 ]im in 
length, 350-360 pm in width, mean 565 ]im x 350 pm, 
length : width ratio 1.6. Collar cells relatively short, 85-160 jam 
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 tes- 
ta cells strongly undulated. Anticlinals broad, without bound- 
ary. Outer periclinal walls rather shallow. Collar slightly taper- 
ing, operculum therefore rather small. Opercular ring adjacent 
to collar sunken. 

Seed Micromorphology: Anticlinals crossed by radiating 
longitudinal striae leaving "central field" of randomly orientat- 
ed, small zigzag cuticular foldings of irregular thickness and el- 
evation. 

Remarks: 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 9o-e,^). — Seed Structure 
and Micromorphology: The seeds of B. colombiana Smith & 
Schubert, B. killipiana Smith & Schubert, B. longirostris (Lugo 
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 \xm in B. trispathulata to 655 pm x 470 pm in B. killipi- 
ana. The number of collar cells in the seed circumference var- 
ies from about 17 in 5. 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 cutic- 
ular pattern similar to that of the central field, with short zigzag 



to star-shaped foldings. Begonia colombiana has a very dense 
pattern of short zigzag and short undulated striae; B. trispathu- 
lata has a double structure of linear, undulated, or zigzag striae 
of varying length. The star-shaped cuticular foldings in B. kil- 
lipiana occasionally have a central depression. The seeds of B. 
killipiana collections Killip 7994 and W.S. Hoover 463 resem- 
ble 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. 

Specimens Examined: 
B. colombiana, COLOMBIA: Schultes & Villarreal 7758 (US). 
B. killipiana, COLOMBIA: Killip 7994 (US); W. Scott Hoover 

27. 463 (US). 
B. longirostris, ECUADOR: Lugo 4699 (MO). 
B. trispathulata. VENEZUELA: Steyermark 103480 {US). 

Begonia antioquensis 

Begonia antioquensis (A. DC.) WARBURG (Plate 9/). — Seed 
Structure: Seeds ellipsoid, without distinct differentiation be- 
tween operculum and collar, 510-600 pm in length, 295-360 
pm in width, mean 560 pm x 325 pm, length: width ratio 1.8. 
No characteristic collar cells; all testa cells more or less isodia- 
metric 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, an- 
ticlinals rough cross-hatched. Cuticle distinctly double-struc- 
tured. Elevated parts, about 12 per cell, irregularly round or 
star-shaped, with central depression and interconnected by ra- 
diating linear cuticular striae. 

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

Begonia hexandra 

Begonia hexandra IRMSCHER (Plate 9h). — Seed 
Structure: Seeds broadly ellipsoid, without distinct border- 
line 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 anticli- 
nal walls. Anticlinals relatively broad, without boundary. Cell 
pattern difficult to recognize due to shallowness of outer peri- 
clinal walls. Micropyle a small, irregular bulge without distinct 
exostome and hilar scar. 



12 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 



Seed Micromorphology: Cuticular pattern, if present, re- 
duced, with longitudinal striae. 

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

Begonia diversistipulata Group 

Begonia diversistipulata IRMSCHER (Plate 9j). — Seed 
Structure: Seeds ellipsoid, with flat operculum, 345-435 pm 
in length, 270-315 pm in width, mean 390 pm x 295 pm, 
length:width ratio 1.3. Collar cells 80-150 pm in length, mean 
1 10 pm, number in seed circumference about 13. Ratio of col- 
lar-cell length to seed length 1 :3.5. Testa cells polygonal, ar- 
ranged in rows. Anticlinal walls relatively thin, straight or 
slightly undulated. Micropyle almost not protruding. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar 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. um- 
bellata H.B.K. resemble those of B. diversistipulata in the thin, 
straight or almost straight anticlinal walls and a simple cuticu- 
lar 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-de- 
scribed collection (Killip <& Hazen 9165) by having a denser 
cuticular pattern, consisting of a double structure of mainly 
long zigzag striae. 

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

Hoover 443 (US). 

Ungrouped Species 

Species Observed (Plate 9l~n). — The seeds of Begonia 
montana Warburg, B. raimondi Irmscher, B. hirta (Klotzsch) 
Smith & Schubert, and one collection of B. formosissima (Lo- 
pez-Figueiras & Dugarte 29409) could not be incorporated 
into one of the groups of section Casparya described above. 

Seed Structure and Micromorphology: 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 granu- 
lar to short zigzag and more uneven in elevation in B. formosis- 
sima. 

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 



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); 

H. Humbert 26725 (US). 
B. raimondi, PERU: A. Raimondi 2982 (B). 

2.2. Section Rossmannia (Klotzsch) A. DC. 

Plate \Oa-c 

The taxon Rossmannia was first described by Klotzsch as a 
genus in 1855 and was transferred to sectional level by A. De 
CandoUe 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. Bego- 
nia rossmanniae is a climbing shrub that occurs in humid for- 
ests of Ecuador, Peru, and Colombia. 

Type Species. — Begonia rossmanniae A. DC. (Plate lOa-c). 

Seed Structure: Seeds narrowly ellipsoid, micropylar and 
chalazal ends extended, one or both sides often curved, render- 
ing seeds J- or slightly S-shaped. Micropylar end of seed com- 
posed of uncoUapsed, air-filled cells, chalazal end tapering, 
with elongated, collapsed cells. Length 645-710 pm, width 
135-150 pm, mean 675 pm x 140 pm, length: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, num- 
ber 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 Lugo S. 4824 
(AAU); J. Jaramillo & F. Coello 3218 (AAU). 

2.3. Section Hydristyles A. DC. 

Plate \Od-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 Irm- 
scher 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 fe- 
male flower. The species are semishrubs and occur in Bolivia, 
Colombia, Ecuador, and Peru. 

Type Species. — Begonia bridgesii A. DC. (Plate 10/). 

Seed Structure: Seeds ellipsoid, 440-480 pm in length, 
205-235 jam in width, mean 460 pm x 215 pm, length: 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. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar 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 \Qd,e,g-k). — Seed Struc- 
ture 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 1 75 pm and 380 jam x 1 85 pm, re- 
spectively. The longest ones are found in B. santarosensis 
Kuntze, with a mean size of 630 |am x 205 pm and a 
length:width ratio of 3.1. The anticlinal walls vary from weak- 
ly undulated in B. subcaudata: to undulated in B. andina Rus- 
by, B. juntasensis, and B. santarosensis; to strongly undulated 
in B. unduavensis Rusby. 

Thicker anticlinal walls with sunken anticlinals are found lo- 
cally in B. juntasensis and B. unduavensis {G. Mandon 1089). 
More distinct pockets are found in B. juntasensis and B. santa- 
rosensis. 

Specimens Examined: 
B. andina, BOLIVIA: R.S. Williams 1566{K.). 
B. juntasensis, PERU: H.E. Moore Jr., Salazar, & Smith 8601 

(US). 

B. santarosensis, BOLIVIA: s.n. (P). 
B. subcaudata, BOLIVIA: St.G. Beck 9253 (US). 
B. unduavensis, BOLIVIA: St.G. Beck 4691 (US); G. Mandon 
1089 (K). 

2.4. Section Warburgina O. Kuntze 
Plate 10/ 

The section was named by O. Kuntze in 1893 on the basis of 
its then newly described species, B. comata. The section is mo- 
notypic and is restricted to Bolivia. The characters of the sec- 
tion 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 10/). 

Seed Structure: Seeds ellipsoid to narrowly ellipsoid, 
365-435 pm in length, 170-185 pm in width, mean 420 pm x 
175 pm, length: width ratio 2.2. Collar cells elongated, some- 
times 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 nipple- 
shaped. 

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. 

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

2.5. Section Gobenia A. DC. 

Plate 1 \ a-d.f.g 

The section was established by A. De CandoUe in 1859 and 
was retained as such by subsequent monographers. It includes 
about 15 species and occurs in the nothem Andes, mainly Ec- 
uador. 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 subtend- 
ed 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, length: 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 nipple- 
shaped, 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. 

Remarks: Seeds of collection Ed. Andre 3315 (originally 
identified as B. hederacea A. DC.) deviate from above-de- 
scribed collection (W.H. Camp E 4974) in the following char- 
acters: mean seed size 420 pm x 170 pm, length: width ratio 
2.5; number of collar cells in seed circumference about 1 1; tes- 
ta cells with more pronounced anticlinal walls and locally 
sunken anticlinal boundaries. 



14 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 



Specimens Examined: 
B. maurandiae, ECUADOR: W.H. Camp E 4974 (K). COLOMBIA: 
Ed Andre 3315 (K). 

Other Species Observed (Plate 1 \b,c.f.g). — Begonia pu- 
lulahuana 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 vari- 
able in shape, sometimes somewhat J-shaped and/or slightly 
distorted. Mean seed size is 545 ]im x 2 1 5 ]im in B. pululahua- 
na. 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. 

Specimens Examined: 
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). 

2.6. Section Meionanthera A. DC. 

Plate \\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 an- 
thers 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 spe- 
cies is restricted to Colombia. The seeds are not very character- 
istic and resemble the ordinary type of begonia seed. 

Seed Structure and Micromorphotogy: The seeds of B. hol- 
tonis 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 nipple- 
shaped. 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 i575(US). 

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

Plate 1 \j-n 

The species of the small sections Lepsia and Tittelbachia re- 
semble each other in several floral characters and in outer ap- 
pearance. 

Type Species. — Begonia foliosa H.B.K. war. foliosa, type 
species of section Lepsia; B. fuchsioides Hooker var. fuchsio- 
ides, type species of section Tittelbachia. 

Seed Structure and Micromorphology: The seeds of the 
two type species resemble the ordinary type of begonia seed. 



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 length: width ratio of 2.5. The seeds of B. 
foliosa var. rotundata Smith & Schubert have a very dense cu- 
ticle that somewhat obscures the anticlinal walls. The synony- 
my of B. poeppigiana A. DC. with B. foliosa var. australis 
Smith & Schubert is sustained by seed micromorphology. 

Specimens Examined: 
B. foliosa var. australis, ECUADOR: Jameson s.n. (B). PERU: 

Matthias & Taylor 5905 (MO). 
B. foliosa var. foliosa. COLOMBIA: Oscar Haught 6159 (K); 

PERU: Herb. Splitgerberianum (L). 
B. foliosa var. putzeysiana, COLOMBIA: Killip & A.C. Smith 

19817, 20090 (US). 
B. foliosa var. rotundata, COLOMBIA: McDougal & Roldan 

3540 (US). 

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 
5005 (US). 

Other Species Observed. — The seeds of B. microphylla 

A. DC. are about 550 pm in length and differ from the species 
described above by having a more irregular seed shape, a 
broadly nipple-shaped operculum, and testa cells with more el- 
evated 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 be- 
tween the collection F.J. Breteler 4643 and B. foliosa collec- 
tions. 

Specimens Examined: 

B. microphylla var. microphylla, VENEZUELA: P.E. Berry 3291 
(MO); F.J Breteler 4643 (MO); L. Ruiz-Teran 393 (US). 

2.8. Section Eupetalum (Lindley ex Klotzsch) A. DC, 
Including the Former Section Huszia (Klotzsch) A. DC. 
Plates 12, I3a-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, occasion- 
ally extending into Venezuela or occurring in Mexico. 

The species of the two sections as formerly recognized re- 
semble 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's- 
foot-like cuticular striae, the seeds lack distinct features charac- 
teristic 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 Micro- 
morphology: The seeds of the former type species, B. octo- 
petala THeritier, have a mean size of 340 pm x 180 \xm 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, testa! pattern, and in the very 
dense cuticular pattern, which consists of short zigzag and 
crow's-foot-like striae. The synonymy of B. macbrideana Irm- 
scher with B. erythrocarpa as stated by Smith and Wasshausen 
(1984) is not substantiated by the seeds examined in this study. 
Begonia macbrideana has a different cuticular pattern and fur- 
ther 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 |im X 300 pm and a length : width ratio of 1 .5. 

Remarks: 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. 

Specimens Examined: 
B. cinnabar ina, BOLIVIA: R. de Michel 16 (US). 
B. erythrocarpa, PERU: Wasshausen & Salas 1194 (K). 
B. hydrophylloides, COLOMBIA: M. Idrobo & Evans Schultes 

560 (US). 

B. macbrideana, PERU: Weberbauer 2011 (B). 
B. macra A. DC. aff, VENEZUELA: Steyermark & Rabe 97300 
(B). 

B. monophylla, MEXICO: C.G. Pr ingle s.n. (L, PRE); J.N. Rose 
c.s. 9367 (P). 

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

c.s. 2709 (US); O. Tovar 3600 (US). 
B. pastoensis, COLOMBIA: F.C. Lehman 5404 (B); J. Triana s.n. 

(P). 

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). CULTI- 
VATED: van Veldhuizen 1108 (WAG). 

Section Eupetalum. — Seed Structure and Micro- 
morphology: 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 |im, with a length: width ratio 
of 1.7. They resemble the seeds of the former section Huszia 
species B. cinnabarina Hooker, B. hydrophylloides Smith & 



Schubert, B. pearcei Hooker, B. serotina A. DC, and B. tum- 
bezensis Irmscher in general characters, their length : width ra- 
tio, 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 3117 (K); 
Sela 259 (B). 

B. novogranatae A. DC, COLOMBIA: M.T. Dawe 272 (K, as B. 
inanis Irmscher, isotype); P.J. Grubb, Curry, & Fernandez- 
Perez 628 (K). 

2.9. Section ^/?/^ro/i C DC. 

Plate I3d,e 

This monotypic section differs from the other sections by 
having globose, wingless fruits; it is endemic to Ecuador. 

Type Species.— Begonia exalata C. DC. 

Seed Structure and Micromorphology: The seeds of B. ex- 
alata conform to the ordinary type of begonia seed. The mean 
seed size is 335 ]xm x 210 |jm, with a length: width ratio of 1.6. 
The anticlinal walls are straight, slightly curved, or obscured 
undulated. The operculum is nipple-shaped. The cuticular pat- 
tern 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 sur- 
face. 

The seeds resemble those of B. pastoensis of section Eupeta- 
lum (Huszia). 

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

2.10. Section ^a/jfl (Klotzsch) A. DC. 

Plate Uf-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 Uh). 

Seed Structure: Seeds ellipsoid to narrowly ellipsoid, 
somewhat irregular in shape. Length 450-555 pm, width 
210-240 ]xm, mean 510 pm x 225 pm, length: width ratio 2.7. 
Collar cells elongated, 145-250 ]xm 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 

Seed Micromorphology: Anticlinal boundaries straight or 
locally sunken. Cuticular pattern with linear or short undulated 
striae. 

Remarks: The seeds of collection Barbour 3993 differ in 
several respects from the above-described collection Weber- 
bauer 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 (VS). 

Other Species Observed (Plate \3f.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 above- 
mentioned 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 nip- 
ple-shaped. The cuticular pattern is short linear to short undu- 
lated 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). 
B. soror, PERU: JJ. Wurdack 7(527 (US). 

3. Sections Occurring both in Brazilian 
AND IN Andean Regions 

Only two sections have a distribution both from Brazil or Ar- 
gentina and from the Andean countries. 

3.1. Section Pilderia A. DC. 

Plate \3k.n 

Klotzsch's genus Pilderia was reduced to sectional level by 
A. De CandoUe (1859). The section is characterized by stami- 
nate 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 dis- 
tribution from Brazil and Peru to Venezuela. 

Type Species. — Begonia buddleiifolia A. DC. (Plate \ 7>k,n). 

Seed Structure: Seeds conforming to ordinary seed type. 
Seeds ellipsoid, mean size 285 pm x 150 pm, length: width ra- 
tio 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. Opercu- 
lum nipple-shaped. 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 

Seed Micromorphology: Anticlinal boundaries flat, some- 
times locally sunken. Cuticular ornamentation consisting of 
zigzag striae of various length. 

Specimens Examined: 
B. buddleiifolia, BRAZIL: E. Ule 6466 (K). ECUADOR: Holguer 

Lugo S. 5042 (K). VENEZUELA: Allart 387 (B). NOUVELLE 

GRENADE: Goudot s.n. (P). 

3.2. Section Australes Smith & Schubert 

Plate Ul.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 flow- 
ers 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 Ar- 
gentina. Begonia micranthera, with several varieties, also ex- 
tends 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 
13w,o). 

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, respec- 
tively. Relatively many testa cells, those adjacent to collar 
somewhat elongated, chalazal ones polygonal. Anticlinal walls 
straight, slightly curved, or slightly undulated. Operculum 
cone-shaped. 

Seed Micromorphology: Anticlinal boundaries flat, locally 
sunken in B. micranthera \ax.fimbriata. Cuticle with short, un- 
dulated striae and with slight double structure in B. micran- 
thera var.fimbriata and war. foliosa. 

Specimens Examined: 
B. micranthera war. 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 & 
Hjertings.n. (L). BOLIVIA: V.M. Cardenas 4710 {US). 
Other Species Observed (Plate 13/). — The seeds of B. taf- 
iensis Lillo closely resemble those of B. micranthera var. foli- 
osa in size and morphological characters. 

Specimen Examined: 
B. tafiensis, ARGENTINA: S. Venturi 3093 (US). 

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, Urni- 
formia, 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 Pari- 
etoplacentalia. 

4.1. Section Urniformia Houghton ex Ziesenhenne 
Plate \Aa,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 I4a,b). 

Seed Structure: Seeds ellipsoid, 540-620 yim 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. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticle 
smooth, without ornamentation; locally, striae on anticlinal 
walls of operculum. 

Specimens Examined: 
B. heydei. COSTA RICA: Haber & Bella 7645 (MO); R.A. 

Ocampo 1323 (CR); Sione & Stone 2712 (US). 

4.2. Section Gireoudia (Klotzsch) A. DC. 
Plates 14c-«, \Sa-c 

Gireoudia was described by Klotzsch in 1 854 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 Magnu- 
sia 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 sec- 
tion Auriformia Ziesenhenne by the synonymy of B. bakeri C. 
DC. with B. cardiocarpa Liebmann (Burt-Utley, 1985). We ac- 
cept the proposal by Burt-Utley (1985) to select B. plebeja 
Liebmann as lectotype of section Gireoudia above the more ar- 
bitrarily 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 te- 
pals 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,/). 

Seed Structure: Seeds ellipsoid. Mean seed size 365 pm x 
185 pm, length: width ratio 2.0. Testa cells polygonal or more 



elongated. Anticlinal walls slightly curved. Operculum nipple- 
to broadly nipple-shaped. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar 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 \Ad.e.g-n. 15a-<:). — 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 Structure: Seed length varies from 310 pm in B. jen- 
mannii Tutin to 445 pm in B. crassicaulis Lindley and B. uro- 
phylla 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). 

Seed Micromorphology: The anticlinal boundaries are al- 
ways 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 & Cha- 
misso. The cuticular pattern is fine and very dense, as in B. car- 
diocarpa. 

Specimens Examined: 
B. barkeri. MEXICO: Bourgeau 2968 (L); Ch.L. Smith 690 (US). 
B. cardiocarpa. COSTA RICA: K. Utley 597 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. crassicaulis. GUATEMALA: J.A. Steyermark s.n. (US). 
B.fusca Liebmann, MEXICO: Botteri & Sumichrast 1631 (P). 
B. heracleifolia Schlechtendal & Chamisso var. heracleifolia. 

MEXICO: Bourgeau 1583 (P). 
B. involucrata. COSTA RICA: P.C. Standley 34241 (US); Stanley 

& Valerio 48137 (VS). 
B. jenmannii. BRITISH GUIANA (=Guyana): B. Maguire & Fan- 

shawe 23081 (U). 
B. multinervia. COSTA RICA: cult., van Veldhuizen 661 (WAG). 
B. nelumbiifolia, CULTIVATED: Gent, B.K. Boom 16850 (L). 
B. plantaginea Smith & Schubert, MEXICO: E. Matuda 117945 

(US). 

B. sartorii. MEXICO: Bourgeau 2100 (L). 
B. sericoneura. HONDURAS: cult., van Veldhuizen 392 (WAG). 
B. squarrosa Liebmann, MEXICO: cult., van Veldhuizen 623 
(WAG). 

B. urophylla. COSTA RICA: cult., van Veldhuizen 655 (WAG). 

4.3. Section //^jca/j/^ra Ziesenhenne 
Plate \ 5d.e 

In 1974 Ziesenhenne established this monotypic section to 
accomodate B. oaxacana. formerly belonging to section Knese- 
beckia. The section is characterized by the presence of erect 



18 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 



fruits with six small wings. This character, however, is not al- 
ways 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 or- 
dinary type of begonia seed. 

Type Species. — Begonia oaxacana A. DC. var. oaxacana 
(Plate \ 5d,e). 

Seed Structure: Seeds ellipsoid. Mean seed size 480 pm x 
255 pm, length: width ratio 1.9. Testa cells more or less polyg- 
onal, with straight, curved, or sometimes slightly undulated an- 
ticlinal walls; anticlinal walls thickened. Operculum nipple- to 
broadly nipple-shaped. 

Seed Micromorphology: 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. 

Remarks: The seeds of collection McWilHams & 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 al. 26139 (CR); P.C. 

Standley 38821 (US). MEXICO: R. McVaugh 10266 (US). 

NICARAGUA: Williams & R. Molina 42675 (US). PANAMA: 

R.L. Liesner 285 (P). 

4.4. Section Dissepbegonia Ziesenhenne 

PLATE 15/g 

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 5. 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 ]xm x 205 pm, with a 
length: 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 \Sh.j 

The section is characterized by staminate and pistillate flow- 
ers with four and five tepals, respectively, and filaments united 
into a column. The section comprises the type species B. de- 
candra Pavon ex A. DC. from Puerto Rico and Mexico. The in- 
clusion of a second species, B. trichosepala C. DC. from Gua- 
temala (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 \im x 180 
]im, 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. Opercu- 
lum nipple-shaped. 

Seed Micromorphology: Anticlinal boundaries varying 
among collections: mostly sunken in Krug & Urban 1121, lo- 
cally sunken in Hoffmann 876, and almost always flat in Sinte- 
nis 5341. Cuticular pattern consisting of short linear and short 
undulated striae. 

Specimens Examined: 
B. decandra. PUERTO RICO: O. Hoffmann 876 (B); Krug & 
Urban 1121 (L); P. Sintenis 5341 (P). 

4.6. Section Weilbachia (Klotzsch & Oersted) A. DC. 
Plate \Sk-o 

Weilbachia was originally described as a genus but was re- 
duced to a section by A. De Candolle (1859). The section prob- 
ably includes section Liebmannia Ziesenhenne, as it is similar 
to, if not indistinguishable from, section Weilbachia (Burt-Ut- 
ley, 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 Amer- 
ica 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. 

Species Observed (Plate 1 5k-o). — Seed Structure: Seeds 
ellipsoid, varying in size from 320 jam x 195 jam in B. aridicau- 
lis Ziesenhenne to 415 pm x 215 |im 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 Zie- 
senhenne. Operculum nipple-shaped. 



NUMBER 90 



19 



Seed Micromorphology: Anticlinal boundaries always flat. 
Cuticular pattern short undulated, short linear, or granular. Out- 
er periclinal cell wall sometimes rather thin, almost without cu- 
ticular ornamentation, and reflecting underlying pits, as in B. 
imperialis Lemaire. 

Specimens Examined: 
B. alice-clarkiae Ziesenhenne, MEXICO: cult., van Veldhuizen 
497 (WAG). 

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. Dwyer 15321 (MO). MEXICO: E. 

Matuda 5406 (MO). 
B.pustulata, GUATEMALA: H. von TUrckheim 1181 (US). 

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 /?«/zopavom« A. DC. 

Plates 16, 17 a. b 

The section was established by A. De Candolle in 1859. Irm- 
scher (1949) discussed the delimitation of the section. Begonia 
corredorana C. DC. and B. thiemei C. DC, affiliated to this 
section by Barkley and Golding (1974), were included in sec- 
tion Gireoudia by Burt-Ufley (1985). 

Most species of the section have only two tepals in the stam- 
inate and pistillate flowers, but in some species there are three 
tepals in the staminate flowers and up to four tepals in the pis- 
tillate flowers. The connective of the stamens is a little extend- 
ed. The styles are deeply two-parted and are sometimes divided 
again. The plants are suffrutescent, shrubby, or climbing, pre- 
dominantly with pinnately veined leaves, and with small decid- 
uous bracteoles. The section comprises about 35 species, most- 
ly from the Andes, but eight species are reported from Central 
America and/or Mexico. 

Type Species. — Begonia alnifolia A. DC. (Plate I6a.b). 

Seed Structure: Seeds ellipsoid, resembling ordinary bego- 
nia seed type. Mean seed size of collection Mocquerys 1219 
325 pm X 195 pm, length: width ratio 1.7. Collar cells elongat- 
ed, other testa cells relatively few in number. Anticlinal walls 
of testa cells thin and straight to curved. Operculum nipple- 
shaped. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar pattern linear or undulated. Locally, patches without a 
smooth or fine structure. 

Remarks: Seeds of B. aff. alnifolia collection A.C. Smith 
3169 deviate by having somewhat larger seeds, undulated anti- 
clinals, and a less dense cuticular pattern with underlying pits. 



Specimens Examined: 
B. alnifolia, VENEZUELA: Mocquerys 1219 (P). GUYANA: A.C. 
Smith 3169 (P). 

Species Comparable to B. alnifolia (Plate \6c-h,k,l). — 
Seeds of most of the species observed of section Ruizopavonia 
resemble one another in their relatively small size, curved un- 
dulated anticlinals, and in their fine cuticular structure, consist- 
ing of linear or undulated striae. 

Seed Structure and Micromorphology: 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 dis- 
tinctly 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. 

Specimens Examined: 
B. bracteosa, PERU: Ellenberg 815 (U). 
B. carpinifolia, COSTA RICA: Kappelle & Monge 3635 (CR). 
B. consobrina Irmscher, COLOMBIA: Schultes & Villarreal 

7704 (K). 

B. convallariodora, COSTA RICA: Scott Hoover 582 (MO). PAN- 
AMA: Seibert 207 (K). 

B. cooperi, CULTIVATED: van Veldhuizen i96(WAG). 

B. corredorana, COSTA RICA: A.F. Skutch 4733 (US). 

B. peruviana, PERU: Sandeman 4378 (K). 

B. seemanniana var. seemanniana, PANAMA: Seemann 1661 
(K, lectotype). 

B. thiemei C. DC, MEXICO: Martinez Calderon 2258 (US). 
B. viridiflora A. DC var. parviflora Smith & Schubert, PERU: 
Mexia 04152 (MO, isotype). 

Species Differing from B. alnifolia (Plates \6j,m-o, 
\la,b). — The seeds of four species examined differ distinctly 
from those described above. 

Begonia udisylvestris C. DC: Mean seed size 545 pm x 
295 pm, length: 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. 

Begonia suprafastigiata Irmscher: Mean seed size 435 pm 
X 190 pm, length: width ratio 2.3. Testa cells elongated, in reg- 
ular rows in continuation of collar cells. Anticlinal walls of tes- 
ta cells distinctly undulated. 

Begonia cuatrecasiana Smith & Schubert: Seeds ellipsoid 
to narrowly ellipsoid, somewhat varying in shape and dimen- 
sions. Operculum obtuse, chalazal end extended. Mean seed 
size 385 pm x 150 pm, with length: width ratio of 2.6. Anticli- 
nal walls curved to undulated, locally with pockets. Anticlinal 



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). 

Begonia estrellensis C. DC: Seeds narrowly ellipsoid, 
with obtuse operculum and extended chalazal end. Mean seed 
size 625 \xm x 170 pm, length: width ratio 3.7. Testa cells elon- 
gated. 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. 

Remarks: The seeds of B. estrellensis resemble those of B. 
santarosensis of section Hydristyles. The seeds of 5. udisylves- 
tris resemble those of B. oaxacana of section Hexaptera. 

Specimens Examined: 
B. cuatrecasiana, COLOMBIA: Forrero-Jaramillo 2403 (COL). 
B. estrellensis. COSTA RICA: Nelson Zamora c.s. 512 (CR). 

PANAMA: Liesner 1023 (L). 
B. suprafastigiata, PERU: Weberbauer 7907 {B, holotype). 
B. udisylvestris, COSTA RICA: Burger & Stoke 5250 (CR). 

6. Sections with a Wide Neotropical Distribution 

The four sections discussed below comprise species distrib- 
uted over a wide area, ranging from Brazil to Mexico. Two sec- 
tions. Begonia and Knesebeckia, also have species in Asia. 

6. 1 . Section Doratometra (Klotzsch) A. DC. 

Plate \ lc-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 \ld,g). 

Seed Structure: Seeds elliptic, 315-365 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 nipple- 
shaped. 

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. Stan- 
ford c.s. 972 (MO). 

Other Species Observed (Plate \ lc.e.f.h-m).—l\\Q seeds 
of species of this section show some variation in size and mi- 
cromorphology; the seeds of B. prieurii A. DC. and B. steyer- 
markii Smith & Schubert in particular are quite characteristic. 



Seed Structure and Micromorphology: The seeds of B. fil- 
ipes. 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 gener- 
al morphology and in the granular cuticular ornamentation. The 
seeds of B. tonduzii C. DC. also are shorter than 300 pm and re- 
semble the above-mentioned species in most characters; how- 
ever, they deviate by having a sharp demarcation of the anticli- 
nal walls. 

The seeds of B. hirsuta Aublet and B. hirtella are about the 
same size as those of B. wallichiana and have a similar cuticu- 
lar 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 es- 
caped in Java and Sri Lanka more resemble seeds of B. hirsuta. 

The seeds of B. prieurii and B. steyermarkii distinctly devi- 
ate 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 col- 
lections 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 Cas- 
parya in general shape and in testal pattern. 

Specimens Examined: 
B. filipes. PANAMA: I.M. 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: J.A. Steyermark 

95138 (VS). 

B. prieurii. FRENCH GUIANA: Granville 2519 (US); C. Sastre 

1698 (US), 1733 (U). brazil: H.S Irwin c.s. 48113 (US); T. 

Plowman c.s. 8243 (US). 
B. semiovata. BRITISH GUIANA (= Guyana): B. Maguire & Fan- 

shawe 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 com- 
prises parts of the former section Begoniastrum A. DC. The 
taxonomic delimitation of section Begoniastrum changed sev- 



NUMBER 90 



21 



eral times. According to Baranov and Barldey (1972), section 
Begonia includes the former subsection Eubegonia Warburg 
and the sections Moschkowitzia (Klotzsch) A. DC. and Cya- 
tocnemis (Klotzsch) A. DC, but Knesebeckia, reduced by 
Warburg (1894) to a subsection, is again a section in its own 
right. Section Begonia has no unique characters and is cir- 
cumscribed 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 fil- 
aments 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 Neotro- 
pics, but according to Barkley and Golding (1974), it also in- 
cludes 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, Para- 
guay, 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, J). — Type species of 
section Begonia. 

Seed Structure: Seeds elliptic, 295-420 ^im in length, 
180-205 pm in width, mean 360 pm x 195 pm, length: width 
ratio 1.8. Testa cells polygonal. Anticlinal walls thin, straight, 
or almost straight, but undulated at bases. Operculum nipple- 
shaped. 

Seed Micromorphology: Anticlinal boundaries flat. Cuticu- 
lar 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 \8b.c.e-h,k). — The 
seeds observed of species originating from the Caribbean re- 
gion all belong to the ordinary begonia seed type and more or 
less resemble B. obliqua. 

Seed Structure and Micromorpholology: Begonia rotundi- 
folia Lamarck and B. glandulifera Grisebach quite closely re- 
semble B. obliqua in size, shape, and the thin anticlinals and 
outer periclinal walls. 

The seeds of B. odorata Willdenow and B. retusa Schulz re- 
semble 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. cu bens is Hasskarl and of B. plumieri A. DC. 
var. barahonensis O.E. Schulz differ by having almost straight 
anticlinals and more zigzag striae. 



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. V. Morton 5066 (US). 
B. aff odorata. DOMINICA: J. Jeremie 1105 (P). 
B. plumieri var. barahonensis, SANTO DOMINGO: Padre Miguel 

Fuertes 432 (L). 
B. retusa, SABA: A.L. Staffers 3116 (U). 

B. rotundifolia. WEST INDIES: Hortus Bot. Liege (cult.); Hortus 
Bot. Nancy (cult.). 

Mainly Andean Species Observed (Plate ISJ.l.m). — Seed 
Structure and Micromorphology: The seeds of B. guaduensis 
H.B.K., B. cyatophora (type species of former section Cya- 
thocnemis), 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 oi 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 

(MO). 

B. guaduensis. GUYANA: Maas & Westra 3877 (U). PANAMA: 

C.E. Smith Jr. & H. Morgan Smith 32 72 (US). 
B. portillana. MEXICO: Dunn. Le Doux. & Torke 21820 (MO). 

Begonia cucullata — Begonia fischeri Group 

Begonia cucullata WiLLDENOW (Plate \9a-d). — Seed Struc- 
ture 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 length: 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 315 x 200 
pm, and a length: 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 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 



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.M. Pedersen 
10232 (P). PARAGUAY: E. Hassler 6130 (P, isotype); E. 
Hassler 7884 (P, isotype); K. Fiebrig 5125 (L). 
B. cucullata var. cucullata, BRAZIL: d'Alleizette s.n. (L); Irwin, 
Maxwell, & Wasshausen 19961 (P); Y. Mexia 5190 (U); Hj. 
Mosen 1598 (P). PARAGUAY: Jorgensen 34 73 (US). URU- 
GUAY: H.H. Bartlett 21359 (P). 

Other Species Observed (Plate \9e-m). — The seeds of all 
collections of the more widespread B. fischeri Schrank are nar- 
rowly ellipsoid with an obtuse micropylar end and with a sunk- 
en hilum and an extended chalazal end. They resemble the sim- 
ilar 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 out- 
er walls sometimes reflect underlying pits. Begonia fischeri 
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. balan- 
sae C. DC, B. descoleana Smith & Schubert, B. meridensis A. 
DC, B. per-dusenii Brade, B. schmidtiana Regel, and B. sub- 
villosa Klotzsch, mainly from Brazil and/or Paraguay and Ar- 
gentina, 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 (am 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. per- 
dusenii with broad anticlinals and B. alchemilloides with a less- 
pronounced cuticular pattern. 

Specimens Examined: 
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 & Silva 59701 (U). COSTA RICA: B. Hammel 8377 

(MO). VENEZUELA: Steyermark & Rabe 96605 (P); Steyer- 

markc.s. 100258 {?). 
B. fischeri var. klugii, PERU: G. Klug 3389 (MO, cotype). 
B. fischeri var. macroptera (Klotzsch) Irmscher, BRAZIL: B.B. 

Pickel 2466 (US). 
B. fischeri var. palustris (Bentham) Irmscher, COLOMBIA: 

Hartweg 1022 (?). 
B. meridensis, VENEZUELA: Hoist & Liesner 3159 (MO). 
B. per-dusenii, BRAZIL: L.B. Smith, Klein, & Schnorrenberger 

1 1728 (K). 

B. schmidtiana, BRAZIL: B.K. Boom 15916, cult., Hort. Gent 
(L). 



B. subvillosa var. leptotricha, PARAGUAY: K. Fiebrig 5354 (P, 
isotype). 

B. subvillosa var. subvillosa, BRAZIL: G. Hatschbach 21525 
(L); L.B. Smith & Reitz 1269 (US). 

Ungrouped Species 

Begonia organensis BRADE (Plate 18«). — 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 fim x 255 
|im, with a length: 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. 

Specimen Examined: 
B. organensis, BRAZIL: D. Sucre c.s. 3005 (MO). 

6.3. Section Knesebeckia (Klotzsch) A. DC. 

Plates 20, 21a-g 

Section Knesebeckia was formerly considered a subsection 
of section Begoniastrum A. DC. by Warburg (1894). The sec- 
tion now includes the former subsection Rachia Klotzsch of the 
former section Magnusia Klotzsch (Irmscher, I960) 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 fila- 
ments, which often are monodelphous. Some species are tuber- 
ous, and several also produce bulbils in the leaf axils. The sec- 
tion 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 spe- 
cies. 

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. Cuticu- 
lar structure mainly short linear. 

Specimen Examined: 
B. incarnata var. incarnata, MEXICO: Liebmann 177 (US). 



NUMBER 90 

Other Species Observed (Plates 20b,c.e-n, 2la-g). — 
Seed structures vary between the Central American and the 
Mexican species. 

Seed Structure and Micromorphology: Begonia kellerman- 
nii C. DC. and B. peltata Otto & Dietrich resemble B. incarna- 
ta in the thin, undulated anticlinal walls. The seeds of B. bois- 
sieri 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 Doratome- 
tra, 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 pat- 
tern, consisting of a mainly granular ornamentation. The seeds 
of B. angustiloba A. DC, B. falciloba Liebmann, B. ignea 
Warzewicz ex A. DC, and B. uniflora 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 re- 
semble one another in their short lengths, 280 and 295 pm, re- 
spectively, 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 above- 
described 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 bound- 
aries; and the mainly granular to short linear cuticular orna- 
mentation. 

Specimens Examined: 
B. angustiloba. MEXICO: M.L. Diguet s.n. (P). 
B. boissieri. MEXICO: cult., van Veldhuizen 747 {V^hG). 
B. dichroa, BRAZIL: cult., Ziesenhenne s.n. 
B. falciloba, MEXICO: M. Bourgeau 649 (P). 
B. gracilis var. gracilis, 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: 

van Veldhuizen 618 (WAG). 
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. 

Boom 14288 (L). 
B. sandtii, MEXICO: cult., Ziesenhenne s.n. 
B. uniflora, MEXICO: J. Roybal (547 (US). 
B. wollnyi, BOLIVIA: cult., van Veldhuizen 435 (WAG). 



23 

6.4. Section Donaldia (Klotzsch) A. DC. 
Plate 2\h-o 

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. burle- 
marxii Brade or B. egleri Brade. 

Type Species. — Begonia ulmifolia Willdenow was de- 
scribed 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 (Ja- 
yasuriya, 1983). 

Seed Structure: Seeds ellipsoid, mean size 290 \xm x 190 
|im, length: 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 ob- 
served are limited to Bolivia, and two are limited to Brazil (see 
"Specimens Examined," below). 

Seed Structure and Micromorphology: The seeds of the 
other four species studied also are relatively small, not exceed- 
ing 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 ex- 
cept for B. dasycarpa, which has long zigzag striae. 

Specimens Examined: 
B. bangii Kuntze, BOLIVIA: A. Miguel Bang 406 (K). 
B. chaetocarpa var. chaetocarpa, BOLIVIA: O. Kuntze s.n. (B, 
isotype). 

B. chaetocarpa var. glabriflora Smith & Schubert, BOLIVIA: 

H.H. Rusby 690 (US, isotype). 
B. dasycarpa, BRAZIL: A. Glaziou 15388 (P). 
B.jairii Brade, BRAZIL: G. Pedro do Cavalo 752 (US). 

Discussion 

Seed Morphology 

The seeds of about 235 Neotropical Begonia species, repre- 
senting 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 ex- 
ceptions 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 Afri- 
can begonias (de Lange and Bouman, 1992), in which all sec- 
tions are distinguishable from one another on the basis of seed 
characters. 

The seeds of Neotropical begonias vary in shape from almost 
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 de- 
termined by flattened, extended, or swollen chalazal ends. A 
flat chalazal end is caused by 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 of 225 pm, are found in B. 
corredorana (section Ruizopavonia), and the longest ones, 
with a mean length of 1450 pm, are found in a collection of 5. 
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 
23 in a collection of B. pectennervia (section Casparya). The 
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 length: 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 elongat- 
ed 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, thick- 
ness, and roughness. The cuticular pattern may be granular, lin- 
ear, undulated, or zigzag. The surface of the cuticle may be 
smooth (section Urniformia), faint, pronounced, or even form- 
ing 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 Casparya. Sometimes the 
structure of the underlying periclinal wall is reflected, showing 
pits or pockets at the bases of undulated anticlinal walls. A cu- 
ticle with a double structure, i.e., with more elevated, scattered 
foldings next to a regular cuticular pattern, is especially found 
in section Casparya. 

Delimitation and Interrelationships of 
Neotropical Sections 

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 distribu- 
tion; one or more of such sections are found in each of the three 



main areas in which Neotropical begonias are found. The sec- 
tions 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 fold- 
ed-over pleats. The seeds of section Solananthera are long be- 
cause of their extended chalazal end. The long seeds in section 
Trendelenburgia have both extended micropylar and chalazal 
ends. In section Enita {Wageneria) the micropylar and/or cha- 
lazal cells of the seeds are uncollapsed and air-filled, resem- 
bling balloons. In section Scheidweileria the surface of the flat- 
tened 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 
their species have seeds that conform to the ordinary begonia 
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 Sc- 
heidweileria, as suggested by the successive numbering of the 
two sections in Die natiirlichen Pflanzenfamilien (Warburg, 
1894; Irmscher, 1925), is supported by seed structure. The 
seeds of the type species B. lobata of section Ewaldia resemble 
those of section Scheidweileria. 

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 sec- 
tion Bradea as proposed by Toledo (1946). The seeds of the 
type species B. rufosericea closely resemble those of B. ar- 
borescens of section Steineria. 

The seeds of species of section Latistigma conform to the or- 
dinary begonia seed type and resemble the seeds of some spe- 
cies of section Gireoudia, e.g., B. cardiocarpa. 

Of the sections mainly confined to the Andean and Guianan 
regions, five have characteristic seeds. In section Casparya the 
seeds are recognizable by a combination of characters, espe- 
cially the roughness of the testal surface, the mostly undulated 
anticlinals, the flat operculum, and sometimes the double struc- 
ture of the cuticle. On the basis of a combination of these char- 
acters, several species groups can be discerned, but they do not 
match the subsectional classification of Irmscher (1925). Un- 
fortunately, we cannot contribute to the discussion on the status 
of the former sections Begoniella and Semibegoniella because 
no seeds of these taxa could be examined. 

Section Rossmannia is the only Andean section having nar- 
rowly elliptic seeds with a swollen micropylar and an extended 
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 sec- 
tion Warburgina in section Hydristyles. Tiie seeds of 5. 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 irregu- 
lar seed shape, a broadly nipple-shaped operculum, and an of- 
ten flattened chalazal end with more elevated anticlinal walls. 
The seeds of section Gobenia resemble those of section Scheid- 
weileria. 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 (sec- 
tion Hexaptera) as stated by Barkley and Golding (1974) is not 
supported. 

The other mainly Andean sections all have seeds that con- 
form 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. ge- 
raniifolia, 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 
fruit 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 regu- 
larly 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. monadel- 
pha, 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 Saue- 
ria 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 monotyp- 
ic section Urniformia show special characters. Begonia heydei 
is the only Neotropical species having seeds with a smooth cu- 
ticle. 

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 dis- 
proved by seed micromorphology. The seeds of the former type 
species B. baker i (= B. cardiocarpa) resemble those of other 
collections of B. cardiocarpa and of B. involucrata. Seed mor- 
phology 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 re- 
stricted arguments for delimitation of sections or relationships 
between these sections. The sections Ruizopavonia. Doratome- 
tra, and Begonia are mutually difficult to delimit (Irmscher, 
1949). All three sections are rather heterogenous in seed struc- 
ture and have species or a group of species with a deviating 
seed structure. The transfer of B. filipes, B. humilis, and B. hir- 
tella from section Begonia to section Doratometra as referred 
to by Barkley and Golding (1974) is supported by seed micro- 
morphology. The conspecificity of B. filipes and B. hirsuta as 
suggested by Burt-Utley (1984) is not supported by seed mi- 
cromorphology. The seeds of B. prieurii and B. steyermarkii of 
section Doratometra deviate from the seeds of the other spe- 
cies 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. cuatre- 
casiana resemble those of section Rossmannia, and seeds of 
B. estrellensis resemble those of section Hydristyles. Seed mi- 
cromorphology does not support the synonymy of B. udisil- 
vestris with B. carpinifolia (Barkley and Golding, 1974). Be- 
gonia udisilvestris most probably does not belong to section 
Ruizopavonia. Doorenbos et al. (1998) placed B. oaxacana of 
the monotypic section Hexaptera together with B. udisylves- 
tris 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 sec- 
tion Gireoudia as indicated by Burt-Utley (1985). 

Within section Begonia, the B. cucullata — B. fischeri group 
is characterized by a testal pattern of undulated anticlinal walls, 
a granular to short linear cuticular structure, and, partly, a nar- 
rowly 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 bego- 
nias 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 (1925) 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), sec- 
tions 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. Dooren- 
bos et al. (1998) moved the Asian species of both section Bego- 
nia and section Knesebeckia to section Diploclinium. 

As shown in this study, the seeds of the American represen- 
tatives of section Knesebeckia are quite diverse in structure. 
Seeds of the Asian section Diploclinium observed by us also 
conform to the ordinary Begonia type: they are mostly relative- 
ly small and show some variation in anticlinal walls and cuticu- 
lar 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 Bego- 
nia, only B. labordei Leveille 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 re- 
lation 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-men- 
tioned species fit well with those of section Spenanthera. There 
are no arguments for a direct relationship of section Casparya 
with Asian species. 

As far as we know, no suggestions have been made about in- 
tercontinental 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 shak- 
en 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 per- 
sistent 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 ad- 
aptations 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. fischeri group of section Begonia. Typi- 
cal 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 specu- 
lative to suggest other types of dispersal in Neotropical bego- 
nias. 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 dis- 
persal for most species of the African sections Filicibegonia, 
Loasibegonia, and Scutobegonia, growing in the sheltered en- 
vironment of the tropical rain forest where wind is an ineffec- 
tive vector in dispersal. Their fruits do not open but rot away. 
Seeds of species in these sections are small and are often pro- 
vided 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 under- 
neath the leaves, as expressed by the name B. rhizocarpa (=5. 
depauperata), and large seeds with a very pronounced cuticular 
pattern. The means of seed dispersal is unknown. A combina- 
tion of accidental dispersal by rain and by adhering to animals 
(epizoochory) seems to be the most probable way of dispersal. 

The species of section Casparya act as rattleburrs; their fruits 
have horns instead of wings, and the seeds are provided with 
striking cuticular patterns, such as prominent, sometimes pli- 
cate foldings or a double structure that might function in dis- 
persal 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 Afri- 
can 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 



27 



all other begonias by a one-celled ovary with three long, hol- 
low, 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 ordi- 
nary begonia type, and seed micromorphology does not pro- 
vide an indication for dispersal. 

The means of seed dispersal often seems to be related to hab- 
itat and growth form (Burt-Utley, 1985). Begonias with special 
adaptations to wind dispersal are mostly climbers and/or epi- 
phytes or have a tendency to do so. For example, this holds in 
sections Enita, Rossmannia, Solananthera, Trendelenburgia, 



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 proba- 
bly that of the Asian ones, distinctly differs from seed dispersal 
in African begonias. In the Neotropical begonias wind dispers- 
al is predominant, and alternative types of dispersal are restrict- 
ed to a limited number of sections. In Africa only about one- 
fifth of the Begonia species are wind dispersed, almost two- 
fifths 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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vised Handbook to the Flora of Ceylon. 4:137-152. New Dehli: 
Amerind Publishing Company. 
Keraudren-Aymonin, M. 

1983. Famille 144, Begoniacees. In Flore de Madagascar et des Comores: 
Plantes Vasculares. pages 1-108. Paris: Museum National d'His- 
toire Naturel. 
Klotzsch, J.F. 

1855. Begoniaceen-Gattungen und Arten. Abhandlungen Kdnigliche 
Akademie Wissenschaften (^cr\m), 1854:1-135. 



Kuntze, O. 

1893. Begoniaceae. Revisio Generum Plantarum. 3:105-106. Leipzig. 
Lange, A. de, and F. Bouman 

1986. Micromorphology of the Seeds in Begonia Section Solananthera A. 

DC. Acta Botanica Neerlandica. 35(4):489^95. 
1992. Seed Micromorphology of the Genus Begonia in Africa: Taxonomic 

and Ecological Implications. Wageningen Agricultural University 

Papers. 91(4):l-82. 
Mabberley, D.J. 

1989. The Plant-Book, xii + 706 pages. Cambridge: Cambridge University 
Press. 

Muller, C. 

1 857. Begonia. In W.G. Walpers, Annales Botanices Systematicae. 4:909. 
Panda, Sauris, and J.J.F.E. de Wilde 

1995. Diversity and Taxonomic Value of Stigmatic Surfaces in Begoni- 
aceae: SEM Analysis. Acta Botanica Neerlandica. 44(2): 139-1 50. 
Pijl, L. van der 

1972. Principles of Dispersal in Higher Plants. 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. Danvini- 
ana. 5:78-117. 

1946. The Begoniaceae of Colombia. Caldasia, 4(16): 1-1 38; 4(17): 

77-107; 4(1 8): 179-209. 
1 955. Studies in the Begoniaceae, IV. Journal of the Washington Academy 

of Sciences. 45(4): 1 10-1 14. 
Smith, L.B., and D.C. Wasshausen 

1979. Begonia of Ecuador. Phytologia, 44(4):233-256. 

1983. Notes on Begoniaceae — I. Phytologia, 52(7):441-451. 

1984. Notes on Begoniaceae— III. Phytologia, 54(7):465-473. 
1 986. 1 33, Begoniaceae. Flora of Ecuador, 25: 1-66. 

Smith, L.B., D C. Wasshausen, J. Golding, and C.E. Karegeannes 

1986. Begoniaceae, Part 1: Illustrated Key; Part II: Annotated Species List. 
Smithsonian Contributions to Botany, 60: 584 pages. 
Sosef M.S.M. 

1 994. Refuge Begonias; Taxonomy, Phylogeny and Historical Biogeogra- 
phy of Begonia sect. Loasibegonia and sect. Scutobegonia in Rela- 
tion to Glacial Rain Forest Refuges in Africa; Studies in 
Begoniaceae, V. Wageningen Agricultural University Papers, 
94(1): 1-306. 
Toledo, J.F. 

1 946. Duas novas especies Brasileiras de Begonia L. Arquivos de Botanica 
do Estado de Sao Paulo, 2(3):61 . 
Warburg, O. 

1894. Begoniaceae. In A. Engler and K. PrantI, Die naturlichen Pflanzen- 
familien, 3(6a): 12 1-l 50. Leipzig. 

Wilde, J.J.F.E. de, editor 

1985. Studies in Begoniaceae, II. Wageningen Agricultural University Pa- 
pers, 84(3): 1-1 29. 

1992. Studies in Begoniaceae, III. Wageningen Agricultural University 
Papers. 91(4): 1-1 51. 
Ziesenhenne, R. 

1948. Begonia cavum. The Begonian. 15(1):20. 

1974. Three New Begonia Sections. The Begonian, 41(1): 1 1-13. 



28 



NUMBER 90 



29 




Plate 1 . — Seeds of sections Trachelocarpus and Solananlhera: a, B. herbacea (Liscdecceales .?.«.), x 1 25; b, B. 
herbacea var. ellipticifolia (Ule 4240), x 1 10, c. detail testa, x 500; d. B. solananlhera (cult.), x 150; e. B. depau- 
perala (Campos Goer 140), x 130;/ B. lanceolata {Smith & Pereira 15343), xlOO; g, B. radicans (Luederwaldt 
s.n.), x80; h, B. integerrima (Pereira 606), x95. 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 




Plate 2. — Seeds of sections Trendelenburgia and Scheidweileria: a, B.fruticosa {Martins 8380), x 100,/ detail 
testa, X 490; b. B. pentaphylla (Maguire c.s. 44596 ), x 1 20, c, detail testa, x480; d, B. luxurians (Hoehne 23 70), 
X 130; e, B. digitata (Martinelli & Maas 3271), x 120; g, B. incisoserrata (Hatschbach & Kummran 45532), 
x\10;h.B. pan'iflora (Killip 7837),x2\0. 



Plate 3. — Seeds of sections Ewaldia and Enita: a. B. lohata (Hatschhach 30073), x 130; b. B. scharffii (Pala- 
cios-Cuezzo 29i0), x 160; c, B. tomenlosa (Brade 18572), x\60-, d. B. rigida (ABS Seed Fund), x 190; e. B. con- 
volvulacea (Schenck 858), x 120;/ B. epibaterium (Scott Mori c.s. 12856), x 140; g. B.fagifolia (Brade 19144), 
X 1 20; h. B. glabra var. glabra (Irwin c.s. 54738 ), x 1 80, k, detail chalaza, x 280; J, B. glabra var. glabra (Laurito 
81 72), x\20. 



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, x510; c, B. sanguinea (Bailey & Bailey 706), detail testa, x450, / seed, xl50; d. B. coccinea 
(Burchell 2I9A), detail testa, x860, g. seed, x 120; e. B. grisea (Si. Hilaire B 2027), x95; h, B. angulata var. 
angutata (Hatschbach 8831), x 1 20; j. B. itaguassuensis (Lourteig 3236), x 1 50; k, B. dichotoma (Boone-Hahn 
25 ), X 1 40; /, B. acida (cult., Liege), x 1 80; m. B. paranaensis (Hatschbach 8941 ), x 1 1 0; «, B. olsoniae (Pereira 
i07),x 110. 



Plate 5. — Seeds of sections Pritzelia. Philippomarlia. Steineria. and Bradea: a, B. hradei (cult.), x 140; b. B. 
hispida (Bailey & Bailey 710) xl30; c. B. membranacea (Curran 170), x200; d. B. lepiophylla {Mo 4331), 
X 170, e. detail chalaza, x440; / B. hookerana (Occhioni 4788), x 140,/ detail testa, x760; g. B. arborescens 
var. arborescens (Grisebach s.n.), x 190; h, B. polyandra (Herb. Hieronymus s.n ), x 140, k, detail testa, x710; 
/, B. oxyphylla (Inh. Vien s.n ), x 190; m. B rufosericea (Oswaldo Hanro s.n ), x 160; n. B. bidenlata (Peckolt 
75), X 160. 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 




Plate 6. — Seeds of sections Bradea, Tetrachia, Gaerdtia, Latisligma, and Pereira: a, B. dentatiloba (L.B. Smith 
1935), X 160; b. B. parvifolia (d'Alleizette s.n.), x 130; c. B. egregia (Santos Lima s.n.), x 120, g. detail testa, 
x720; d. B corallina (Boone-Hahn 114), x 125; e, B. maculata (Maas & Caraula 3149), x 1 15,/ detail testa, 
x 1 140; h. B. undulata (Gaudichaud 1067), x 140; j, B. aconitifolia (Glaziou 13389), x 150; k. B. leathermaniae 
(Moraes 1056), x 180, n. detail testa, x560; /, B. platanifolia (Hatschbach 46298), x 150; m. B. edmundoi 
(Pereira 366), x\40. 



NUMBER 90 




Plate 7. — Seeds of section Casparya: a, B. urticae (Marling et al. 20465), x 105, h. detail testa, x340; c. B. 
fuchsiiflora (Scott Hoover 515), detail testa, x620,/ seed, xl20; d. B. urticae (Bohlin 975), x|20; e. B. longi- 
rostris (Marling & L. Andersson 11608), xl30; g B. gamolepis (Killip & A C. Smith I6037),x]iO: h. B.ferrug- 
inea (Langenheim 3387), x85; / B. ferruginea var. dilatata (Garcia- Barriga 12053), x 115, /t. detail testa, x370. 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 




Plate 8.— Seeds of section Casparya: a. B. trispathulata (Tillett 739-585), xl30, b, detail testa, x770; c, B. 
brevipetala (Steyermark & Mehlin 109955), detail cuticle, x 1690, d. detail testa, x580, g, seed, x 120; e. B. 
trujillensis (Tillett 739-611), xl25;/ B. mariae (Goldsmith 163), xI30; h, B. formosissima (Ruiz-Teran & 
Figueiras 9306), x90,y. detail testa, x400; k. B. lipolepis (Goldsmith 167), x 1 10; /, B. toledana (Steyermark & 
Dunsterville 100604), x 125; m, B. pectennervia, seed (Holm-Nielsen 26762), x 125, n. detail testa (Holm- 
Nielsen 26438), x620. 



Plate 9. — Seeds of section Casparya: a, B. colombiana (Schultes & Villarreal 7758 ), xl20; b, B. kitlipiana 
(Scott Hoover 27), x95, c. detail testa, x280; d. B. trispathulata (Stevermark 103480), detail testa, x550, g, seed, 
X 140; e, B. longirostris {Lugo 4699), x 1 15;/ B. antioquensis (Luteyn 12265), x 140; h. B. hexandra {Core 
/500), X 110; / B. diversistipulata {Giacometto 1 1 ) x\50; k. B. umbellata {Killip & Hazen 9/65), x 105; /, B. 
montana {Funck & Schlim 1044), x 1 15; m, B. formosissima {Lopez- Figueiras & Dugarte 29409), x 100; n, B. 
raimondi {Raimondi 2982), x85. 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 




Plate 10. — Seeds of sections Rossmannia, Hydristyles. and Warburgina: a. B. rossmanniae (Holguer Lugo S. 
4824), X 1 70, b. operculum, x440 {Holguer Lugo S. 4824), c. detail testa, x5 10 (Vogelmann c.s. 1297); d. B. san- 
larosensis (s.n.), x 150, e. detail testa, x400;/ aff. B. bridgesii (Dereims s.n.), x 150; g, B. subcaudala {Beck 
9253 ), x 1 60; h. B. juntasensis (Moore. Salazar. & Smith 8601 ), x 1 80; J. B. unduavensis {Mandon 1089), x 1 50; 
k. B. andina {Williams 1566), x 140; /, B. comata {Beck 12651 ), x 160. 



NUMBER 90 



39 




Plate 1 1. — Seeds of sections Gobenia, Meionanthera, Lepsia, and Tittelbachia: a, B maurandiae, seed (Camp 
E 4974), X 130, d. detail chalaza (Andre 3315), x260; h. B. pululuhuana (Davis 500) x 1 15; c, 5. secunda (Gen- 
try <Sc Shupp 26638), x 150; e. B. holtonis. detail testa (Urihe Urihe 3878), x590, h. seed (Hollon 725), x\70;f. 
B. ynesiae (Mexia 7706), x\\5;g,B. sodiroi (Holm-Nielsen & Jeppesen 1276), x 1 10; j, B.foliosa var. australis 
(Matthias & Taylor 5905), x200; k. B.foliosa war. putzeysiana (Killip & Smith I9817),X\2Q; I. B.foliosa var. 
rotundata (McDougal & Roldan 3540), xl45; m. B. microphylla (Breteler 4643), x 125; n, B. fuchsioides var. 
fuchsioides (Killip <& Smith 20552), x 140. 



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; b. B. pastoensis (Lehman 5404) detail cuticle, x3340, d, seed, x 180; e. B. 
erythrocarpa (Wasshausen & Salas J 1 94), x[SO;f. B. pleiopelala (Buchtien 653), x 150; g, B. macbrideana 
( Weberbauer 201 / ), x 1 30; h. B. geraniifolia (Lourteig 31 1 7), seed, x 1 70, k. detail chalaza, x350; / B. geranii- 
folia (Dowbey s.n.), detail testa, x690; /. B. cinnabarina (de Michel 16), x 160; m. B. hydrophylloides (Idrobo & 
Evans Schultes 560), x200; n. B. serotina (Camp E 3716), x200; o, B. pearcei (van Veldhuizen 580), x 170. 



Plate 13. — Seeds of sections Eupetalum (including former section Huszia), Apteron, Batya. Pilderia, and Aus- 
trales: a, B. tumbezensis ( Weherbauer 7685A ), x220; b, B. monophylla (Pringle s.n. ), x 1 90; c. B. novogranalae 
(Dawe 272), x 190; d. B. exalata (Sodiro 597), x 190, e. cuticle, x 1970; / B. boliviensis (Hawkes c.s. 3620), 
detail testa, x740, g, seed, x 1 70; h, B. monadelpha (Weherbauer 6714), x 120; j. B. soror (Wurdack 1627), 
X 130; k. B. buddleiifolia (Holguer Lugo S. 5042), x220, n, detail cuticle, x2380; /, B. tafiensts (Venturi 3093), 
X 140; m, B. micranthera var. micranthera (Petersen & Hjerting s.n), x 160; o, B. micranthera \aT.foliosa (West 
6216), detail testa, x550. 



42 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 




Plate 14. — Seeds of sections Urniformia and Gireoudia: a. B. heydei (Haber & Bella 7645), x 11 5, detail 
testa, x870; c. B. pleheja {Taylor 17305), x 170, / detail cuticle, x2460; d. B. jenmannii (Maguire & Fanshawe 
2308 J ), X 1 90; e. B. multinervia (van Veldhuizen 661),x\S0;g. B. sericoneura (van Veldhuizen 392 ), detail cuti- 
cle, x27IO, k. seed, xl80; h. B. urophylla (van Veldhuizen 655), x 140;/ B. sartorii (Bourgeau 2100), xl50; /, 
B. crassicaulis (Steyermark s.n.), x 160; m. B. involucrata (Standley 34241), x 190; n, B. conchifolia (Wilbur 
24349), x\ 60. 



NUMBER 90 



43 




Plate 15. — Seeds of sections Gireoudia. Hexaplera, Dissepbegonia. Podandra, and Weilhachia: a, B. barkeri 
(Smith 690), x 160; b. B. cardiocarpa (Ulley 5917), x 180; c. B. heracleifolia (Bourgeau 1583), x 190; d. B oax- 
acana (Davidse et al. 26139) x 140, e. detail testa, x510 {McVaugh 10266), f. B palmeri (Mexia 219), detail 
testa, x560,g, seed, xl90; h, B. decandra (Krug & Urban 1121), xl80,y, detail testa, x590; k. B. aridicaulis 
(van Veldhuizen 529), detail testa, x830, /, seed, x 190; m, B. purpusii (Matuda 5406), x 140; n. B. imperialis 
(DTH 5397), x 145; o, B. alice-clarkiae (van Veldhuizen 497), x 170. 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 




Plate 16. — Seeds of section Ruizopavonia: a, B. alnifolia (Mocquerys 1219), xI80, b. detail cuticle, x2620; c, 
B. peruviana (Sandeman 4378), detail testa, x400,/ seed, xl90; d. B. corredorana {Skutch 4733), x260; e. B. 
carpinifolia (Kappelle & Monge 3635), x 140; g, B. thiemei (Calderon 2258), x200; h, B. bracteosa (Ellenberg 
815), detail cuticle, x 1640, k. seed, x 1 80; / B. udisylvesths (Burger & Stoize 5250), detail testa, x490, m, seed, 
X 1 1 5; /. 5. seemanniana (Seemann 1661 ), x200; n, B. suprafastigiata (Weberbauer 7907), x 145; o, B. cuatreca- 
siana (Forrero-Jaramillo 2403 ), x 1 80. 



NUMBER 90 



45 





Plate 17. — Seeds of sections Ruizapavonia and Doratometra: a. B. estrellensis, xl30 (Zamora c.s. 512), b. 
X 145 (Liesner 1023 ); c. B. steyermarkii (Cowan & Soderstrom 1841 ), x200; d. B. waltichiana (Stanford c.s. 
972), detail cuticle, x2610, g, seed, x 180; e. B. prieurii (Irwin c.s. 48113), detail testa, x420,/ seed, x200; h. B. 
filipes (Thiehaut 41 ), x240; / B. humilis (Egger 1404), x210; k. B. tonduzii (Grayum 8132), x220; /, B. hirsuta 
(Herb. Sptitgerberianum), x 190; m, B. hirtella (Lourteig 2308), x2 10. 



46 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 




Plate 1 8.— Seeds of section Begonia: a. B. obliqua (Duss 97i ), x 1 70, d, detail testa, x 1 890; b, B. rotundifolia 
(cult., Liege), x 180; c, B. glandulifera {Van Steenis 20304), x200; e, B. plumieri var. barahonensis (Miguel 
Fuertes 432), detail testa, xl 150, h. seed, x 160;/ B. odorata (Morton 5066), x 160;g. B. retusa (Staffers 3116), 
x200; j. B. guaduensis (Maas & Westra 3877), xl50; k. B. cubensis (Ziesenhenne s.n.), xI60; /, B. cyatophora 
(Mexia 8128), x 180; m. B. altoperuviana (Weddell 4556), x 170; n. B. organensis (Sucre c.s. 3005), x 130. 



NUMBER 90 



47 




k 



Plate 19. — Seeds of section Begonia: a, B. cucullata var. cucullata, x 125 (Irwin c.s. 19961), b, x 125 (Bartlett 
21359), c. detail cuticle, x 1 730 (Sar/Ze// 21359); d. B. cucullata var. arenosicola (Pedersen 10232),x\90; e, B. 
fischeri war. fischeri (Steyermark & Rate 96605), x 100,/ detail testa, x470; g, B. alchemilloides (Irwin c.s. 
34478),x\90; h. B. balansae {Balansa 3281 ), x\50;j. B. de.icoleana (Hatschbach 9944), xl60; k. B. fischeri 
var. klugii (Klug 3389), x 1 1 5; /, B. per-dusenii (Smith, Klein. & Schnorrenberger 11728), x 190; m. B. subvil- 
losa var. leptotricha (Fiebrig 5354), x 1 80. 



48 



SMITHSONIAN CONTRIBUTIONS TO BOTANY 




Plate 20. — Seeds of section Knesebeckia: a, B. incarnata {Liebmann 177), 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, x970, h. seed, x200;/ B. boissieri (van Veldhuizen 747), x 1 80; g, B. ludwigii (van Veldhuizen 618), x 140; 
/ B. sandlii (Ziesenhenne s.n ), x 170; k, B. angustiloba (Diguet s.n.), x 190; /, B. falciloba (Bourgeau 649), 
x 1 70; m. B. ignea (Pittier & Durand 1299), x 140; n, B. uniflora (Roybal 647), x 160. 



NUMBER 90 



49 




Plate 2 1 . — Seeds of sections Knesebeckia and Donaldia: a. B. oellgaardii (Baker 6396 ), x 1 90; b. B. maynensis 
(Prance c.s. 7409), x220, c, detail testa, x780; d. B. olbia (van Veldhuizen 434), detail testa, x6IO, g. seed, 
X 140; e, B. wollnyi (van Veldhuizen 435), x240;/ B. dichroa (Ziesenhenne s.n.), x 140; h, B. ulmifolia (Hekking 
1428), x210, k, detail chalaza, x420;y, B. dasycarpa (Glaziou 15388), detail testa, x760, /, seed, x 160; m. B. 
chaetocarpa var. chaetocarpa (Kuntze s.n ), x210; n, B. chaetocarpa var. glabriflora (Rusby 690), x 180; o, B. 
bangii (Bang 406), x\SO. 



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year sequence for dates; "9 April 1 976." For months in tabular listings 
or data sections, use three-letter abbreviations with no periods; "Jan, 
Mar, Jun," etc. Omit space between initials of a personal name; "J.B. 
Jones." 

Arrange and paginate sequentially every sheet of manuscript 

in the following order; (1) title page, (2) ab.stract, (3) contents, (4) 
foreword and/or preface, (5) text, (6) appendices, (7) notes section, 
(8) glossary, (9) bibliography, (10) legends, (11) tables. Index copy 
may be submitted at page proof stage, but plans for an index should 
be indicated when the manuscnpt is submitted.