A. DE LANGE
x | and
: | F. BOUMAN

SMITHSONIAN CONTRIBUTIONS TO BOTA

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|. Michael Heyman
Secretary
Smithsonian Institution

SMITHSONIAN CONTRIBUTIONS TO BOTANY © NUMBER 90

Seed Micromorphology of
Neotropical Begonias

A. de Lange
and F. Bouman

SEP | 0 1999

om

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, | 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 ym
in B. fruticosa; most seeds have a length between 300 pm and 600 pm. The shape of the seeds
varies from almost globular to narrowly elliptic, and the length to width ratio ranges from 1.2
in B. hexandra to 8.1 in B. fruticosa. Further differences exist in the shape of the testal cells,
the undulation of the anticlinal walls, the bulging of the outer periclinal walls, and the pattern
and roughness of the cuticle.

Five of the 15 mainly Brazilian, five of the 12 Andean and Guianan, and one of the eight
middle American sections have a seed structure that is characteristic at the sectional level. All
these sections have a relatively restricted geographical distribution, and they may differ in
growth form or habitat. Most species of the other sections, including the larger and more
widely distributed sections Begonia, Gireoudia, and Knesebeckia, have seeds conforming to
the ordinary seed type.

In a number of the sections, the structural differences of the seeds are nicely correlated with
differences in growth form and/or in means of dispersal. In contrast to the African begonias,
the great majority of the Neotropical begonias have anemoballistic dispersal. Seeds may be
adapted to wind dispersal by extended micropylar and/or 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. SERIES COVER
DESIGN: Leaf clearing from the katsura tree Cercidiphyllum japonicum Siebold and Zuccarini.

Library of Congress Cataloging-in-Publication Data
De Lange, A. (Anton)
Seed micromorphology of neotropical begonias / A. de Lange and F. Bouman.
p. em. — (Smithsonian contributions to botany ; no. 90)
Includes bibliographical references.
1. Begonias—Seeds—Morphology. 2. Scanning electron microscopy.
I. Bouman, F. II. Title. III. Series.
QK1.82747 no. 90
[QK495.B4]
580 s—dc2]
[583'.627 1467] 99-30195
CIP

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

Contents

Page

IntrogucHiOn ck ect ee te eee se oe ee ales owes beet e Pew eae donee sad l
ACKNOWICURINCING i 2.5 a okte doe eave eee: oh hoeona eente? 2
raterialand NicthOdS. ciency aay eae coe: oO once oe ts a ee ve 2
Description of Seeds of Neotropical Begonias ................. 00:0 e eee eee 3
1. Sections Mainly Confined to Brazil and Some Adjacent Countries ........... 3
It. Secon IrachelocarpussAsDC: 5 accom Selene nea 2555 see ee )
P22. section SolananineraAn. DC. ayaa wien ewe ee 6 oo oe onus Sis pee es 3
1.3. Section Trendelenburgia (Klotzsch) A. DC. .............0 0000 c eee eee 4
1.4. Section Scheidweileria (Klotzsch) A. DC. ..............0 0.000002 ee 4
Jo: ection Ewaldia AwDG. <2 se 8 ise ce ee oe oe eee eee 5
HOur eS ec tloniueritasSTade nurse ate oe aie sas ae we Saw Sivas sare a eee R)
1.7. Section Pritzelia (Klotzsch) A. DC. ..........0 000002 eee 6
18, GSechOn se niippomartia An DCT ia cress nae. 2 sews 44 ote ee ee d
1.9. Sections Steineria (Klotzsch) A. DC. and Bradea Toledo .............. 7
PPOs SECUON CI ACNIG IANS weirs cir genie wide eee uals ate lai @ aiersee te ee es 8
1.11. Section Gaerdtia (Klotzsch) A. DC. .... 0.00.00 eee 8
Lis SeChOne GustioMaALC: 24 cane. kOe wciwcsuwers ssa eee nene as 8
LiSe Sechionsrerer a Bade: 2,.0 423 Anas eae ee eae ee ene ae 9

2. Sections Mainly Confined to the Andean and Guianan Regions .............. 9
21> “section Casparya(Klotzsch):ArDCs sada ee ee ee ketal ew eee 9
Begoniaurticae: Group acne sea g tos oe 24 be Saete Satin dO ee ee ee 9
BeZOnIae/TUSINE GlOUPL Gees. 6 wp Sm Sea Se Ode aes Be ee ae 10
Beconiairispoiunlaia Group: oo e's we ss SG oS Oke le we 10

BeConia PEeclenner vid GIOUN a5 here eae ee a we 1]

Begonia antioquensis 2.0.0.0... 60 e ene n ees 11
PECOMICCKONOML (ORD NS:5:5 6 Pais ie Rees & caves esis say Das ee 1]

Begonia diversistipulata(Gioup. ish vac os pence woh eee ee a eee ae oe 12

RIN PTOUPCUCS DE CIOS 5 ee tha ese wo aan ec at coe we at ae Shoes 12

2.2. Section Rossmannia (Klotzsch) A.DC. ........0.00...0 0000.00 cee 2
2:3. ‘SectioniHydristyles ALDC., 28562 o4.06 Oe ete ces abe, be vied be Dees ewe 12
24) ssection Warburgina O), Kunze sot eiertideracne soo wks ke oe ce mee Oe 13
Das eOCcuOM GOVeHIOIN G2 12 datas Bee ae ene Mares aoe a eae Sata g 13

2 0.2) eChOn I Vicionaniierad Aa WC pee are ily eben ae eects ain aa ae ee eae we 14

2.7. Sections Lepsia (Klotzsch) A. DC. and Tittelbachia (Klotzsch) A. DC. ... 14
2.8. Section Eupetalum (Lindley ex Klotzsch) A. DC., Including the Former

Section Huszia (Klotzsch) A. DC. 1.0.0.0... 00... ee eee 14
2.9 e SeCUON A DICHOI GA DGs aati. 5 Sud eas banca mai senna ean achee IS
210 pS SecuOMearyathlotzsch) AC DC. 755 ayes ele tauwe ase Shae ee eee 15
3. Sections Occurring both in Brazilian and in Andean Regions ................ 16
Supe SeCHOM YT OCIOON, IOC r 2.824 t8 iota ee ee taete ame head erat anes 16
3.2. ‘Section Ausiraies Sith & SCRE 24.0546 <s 5 ee osd sense eee dace exaen 16
4. Sections Mainly Confined to the Central American, Mexican, and Caribbean
INC PIONS Cem eh ARE aoa REAR AS hie he ok nies Mee he eee Baad dh die chy 16
4.1. Section Urniformia Houghton ex Ziesenhenne ..................0.05- 7
a) section(Gieoudia (Klotzsch) A.C. 6:42.54 Poa es teks ve sae ween 17
4,3, Section Hexaprera Ziesenhenne 2% «sc 2c awiiat ae tioteew tua sae ween 17
44. Section Dissepbevonia Ziesenhienne «24. s0ns Walid es dese s ote dahon es 18

ill

IV SMITHSONIAN CONTRIBUTIONS TO BOTANY

4.5. Section Podangra ADC. saciid Res RO eo a eae ee si ease eels 18
4.6. Section Weilbachia (Klotzsch & Oersted) A.DC. .................0.. 18

5. Section Mainly Occurring in both Andean and Middle American Regions ..... 19
Sol spectionnmizopovonia ADC. a2 sian aa eae eae lls aerate ee 19

6. Sections with a Wide Neotropical Distribution ................ 00000000 ee 20
6.1. Section Doratometra (Klotzsch) A. DC. ........ 00.000 eee 20
6.2. Section Begonia Baranov & Barkley .............. 00.0 e eee eee eee 20
Begonia obligua Gioup 4, a.242e sea ae ae ee ee es, 21

Begonia cucullata—Begonia fischeri Group ...........0..0000 eee ZA
Ungrouped Species: 25a oc awa cea Gee ee conan ee eae oe

6.3. Section Knesebeckia (Klotzsch) A. DC. ......... 0.0... cece eee eee 22
6.4. Section Donaldia (Klotzsch) A.DC. 2.1... 2... cece ee 23
MTSU SIDED setter So ag tele Rt Se eee Ee eae eee ea 23
Seed Mormmhology: 3 oo. sc.7 a aa & en eae acter «artes mae eee nee cet 23
Delimitation and Interrelationships of Neotropical Sections ................... 24
Possible Intercontinental. Relationships. 4.) .44. a6 eee. ees dee ee een 25
Seed Structure in Relation to Dispersal and Growth Form ..................4.. 26

Hiteratune: C1teds joc vousrece eae isa one Le eee 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 um 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.

aa hilum micropyle

operculum

collar cell

other testa cell

FIGURE. |.—Diagram of a Begonia seed with various parts labelled.

220 ym, 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

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 (1994:11) made a

SMITHSONIAN CONTRIBUTIONS TO BOTANY

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

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, 1894).

1.1. Section Trachelocarpus A. DC.
PLATE la-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 (=B. rhizocarpa Fischer ex A. DC.). Seeds were not
available for B. angraensis Brade, B. fulvo-setulosa Brade, or
B. velloziana Walp.

The species of the section are characterized by a rhizomatous
habit and almost equal-sided lanceolate leaves. Moreover, the
inflorescences are unisexual: the male ones are stalked cymes;
the female ones are reduced to a single subsessile flower. The
ovary and fruit have three narrow wings joining a beak-like
elongation bearing tepals and styles with stigmas. All species
are epiphytic, creeping herbs.

TYPE SPECIES.—Begonia depauperata (Plate le).

Seed Structure: Seeds ellipsoid to narrowly ellipsoid,
750-830 pm in length, 305-330 pm in width, mean 800 pm x
320 um, length: width ratio 2.5. Collar cells relatively short,

175-280 pm 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 la—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. /anceolata 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: L.B. Smith & Pereira 15343 (US).

1.2. Section Solananthera A. DC.
PLATE ld.g,h

The section Solananthera was established by A. De Candolle
in 1859. It contains three species restricted to Brazil. The 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 1d).

Seed Structure: Seeds narrowly elliptic to narrowly obo-
vate, mostly straight, sometimes J- or C-shaped. Mean seed
size 755 pm Xx 145 pm, length: width ratio 5.2. Mean length of
collar cells 250 ppm, 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 1g,h).—Seed Structure
and Micromorphology. Begonia radicans Vellozo and B. in-

tegerrima Sprengel have seed structures that resemble those of
B. solananthera in shape, general morphology, and cuticular
pattern. Mean seed sizes are 1060 pm x 170 pm and 885 pm x
155 pm, respectively, and the length: width ratios are 1:6.2 and
1:5.7, respectively. The seeds of B. radicans also strongly 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
3377 (RB).

1.3. Section Trendelenburgia (Klotzsch) A. DC.
PLATE 2a,f

The taxon Trendelenburgia was first described by Klotzsch
as a genus in 1855 on the basis of one of the early Begonia col-
lections by Ludwig Riedel in 1839. A. De Candolle (1864)
changed the status to sectional level. Most probably the section
is monotypic, with B. fruticosa as the type species.

The section is characterized by three-celled fruits with three
equal-sized, very narrow wings and undivided placentas. The
plants are slender-stemmed shrubs with a tendency to climb
and with simple, pinnately veined leaves. 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, asd 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).

SMITHSONIAN CONTRIBUTIONS TO BOTANY

1.4. Section Scheidweileria (Klotzsch) A. DC.
PLATE 2b-e,g,h

The section Scheidweileria was described by Klotzsch as a
genus in 1855. The section comprises six species, one of
which, B. /uxurians, 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 um, length: width ratio 2.4. Collar cells elongate, 180—280
um 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 ym in length, 155—180 pm in width,
with a mean of 315 pm x 170 pm, and have a length: width ra-
tio of 1.9. They most resemble the ordinary type of begonia
seed.

The seeds of B. /uxurians 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
Hm in width, with a mean of 610 pm x 185 pm anda
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 um 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

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

(Sellow s.n. and Martinelli c.s. 8045, respectively).

The seeds of B. incisoserrata A. DC. vary appreciably in
size, being 370-500 pm in length and 170-215 pm in width,
with a mean of 425 pm x 185 pm and a length : width ratio of
2.4.

The species of the section have straight or slightly curved 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); L.B. 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. André K 284 (K); J. Cuatrecasas
11311 (US); Killip 7837 (US). ECUADOR: Holguer Lugo §
1808 (MO).

1.5. Section Ewaldia A. DC.
PLATE 3a—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 11 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, 115—210 ym 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 (UV).

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. /obata 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 ym 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 3¢,f-k

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, 130-475 pm in length, mean 275 pm, number in
seed circumference about 11. 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

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, pl. 4.12)
shows the seed type particular to section Enita.

In all specimens of the species observed, the chalazal side is
flattened, probably from contact with the fruit wall, except in
B. epibaterium (Scott Mori & Forbes Benton 12856), which
has a more tapering, often somewhat asymmetric chalaza. Seed
size in B. epibaterium tends to be a little smaller, as in B. con-
volvulacea. The mean seed size varies from 495 pm x 170 pm
in B. epibaterium (Dos Santos 3408) to 660 pm x 150 pm in B.
glabra (Laurito 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.G. Schubert and B. glabra var. cordifolia (C. DC.)
Irmscher do not show specific characters and more resemble B.
convolvulacea in having less-inflated chalazal cells.

SMITHSONIAN CONTRIBUTIONS TO BOTANY

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 (P).

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 (P). ECUADOR: Grubb c.s. 1199 (K). GUYANA: G. Cre-
mers 81 (P). SURINAM: Indigen 270 (U); H.S. Irwin c.s.
54738, 54818 (U).

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

The section is characterized by male flowers with four 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

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 of 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. Liége.

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 (UV).

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

oe

. coccinea, BRAZIL: Burchell 219A (P); cult., Ziesenhenne s.n.

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

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

sulcata).

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

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

grisea, BRAZIL: St. Hilaire B 2027 (P); H.S. 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
11 (U).

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

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

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).

be & &

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. /eptophylla 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. /eptophylla and are zig-
zag in B. membranacea.

Specimens Examined:

B. leptophylla, BRAZIL: A. Mo 4331 (MO).
B. membranacea, BRAZIL: H.M. Curran 170 (US); Ex herb.

horti Petropolitani Brasilia Castelnuovo (K).

1.9. Sections Steineria (Klotzsch) A. DC. and Bradea Toledo
PLATES 5f-n, 6a,b

Section Bradea was separated from section Steinera by 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 5/7).

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
5g,1).—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

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: Inh. Vien s.n. (1828) (K).

TYPE SPECIES, SECTION Bradea.—Begonia rufosericea To-
ledo (Plate 5m).

Seed Structure and Micromorphology:
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 11873 (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).

Seeds closely re-

1.10. Section Tetrachia 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 pm in length,
250-300 pm in width, mean 530 pm x 275 pm, length: width
ratio 1.9. Collar cells 155-230 ym 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.

SMITHSONIAN CONTRIBUTIONS TO BOTANY

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 I (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. corallina 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 pn, re-
spectively.

Specimens Examined:

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

1.12. Section Latistigma A. DC.
PLATE 6j—I,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 6/).

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

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 Candolle (1864) extended it by including in it Klotzsch’s
genera Jsopteryx, Sassea, and Stibadotheca and his newly de-
scribed sections Aetheopteryx and Andiphila. Warburg (1894)
reduced the genus Casparya to sectional level and reduced De
Candolle’s sections to subsections, actions that were later ac-
cepted by Irmscher (1925). Moreover, he inserted /sopteryx 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 (1955) also merged the five species of the former
genus Begoniella with section Casparya.

The section is characterized by bifid, or many-, or irregularly
branched styles and by triquetrous fruits that are not winged
but have each of the edges terminating in a horn. The capsule
dehisces at the edges. The plants are mostly erect semishrubs
and usually grow above 2000 m elevation, especially in the
Andean region of Colombia and Ecuador and in Venezuela.
The section comprises about 40 species.

Begonia urticae Group

Begonia urticae LINNAEUS F. (Plate 7a,b,d ).—Type species
of section Casparya.

Seed Structure: Seeds narrowly ellipsoid, micropylar ends
flattened. Seed shape slightly varying from ellipsoid to more
ovoid, with greatest width in middle or more to micropylar or
chalazal end. Length 695—780 pm, width 370-390 pm, mean
745 pm x 385 pm. Length: width ratio 1.9.

Collar cells relatively short, 90-155 pm in length, mean 130
yim, 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 Har-
ling et al. 20465. The mean seed size varies from 675 ym x 335
um (Schultes & Villarreal 7786) to 785 ym x 430 pm (rally
192). The length: width ratio varies from 1.7 (Dryander 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 wm 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 am, 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

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); Harling
et al. 20465 (US).

OTHER SPECIES OBSERVED (Plate 7c,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. /ongirostris Bentham (Harling & L. Andersson
11608), and B. species (Scott Hoover & Wormley 1771) 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 pm in B.
gamolepis to 630 pm x 375 pm in B. fuchsiiflora. All collec-
tions have a cuticle with mainly undulated striae of normal
thickness except for collection Scott Hoover & Wormley 1771,
which has a faint double structure.

Specimens Examined:

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

B. gamolepis, COLOMBIA: Barkley & Araque M. 185094 (US);
Killip & A.C. Smith 16037 (B).

B. longirostris, ECUADOR: Harling & L. Andersson 11608
(US).

B. species, ECUADOR: Scott Hoover & Wormley 1771 (MO).

Begonia ferruginea Group

Begonia ferruginea LINNAEUS F. (Plate 7h—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 um.
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-

SMITHSONIAN CONTRIBUTIONS TO BOTANY

lar plicas and foldings are long and are undulated or somewhat

zigzag.

Specimens Examined:

B. ferruginea var. dilatata, COLOMBIA: H. Garcia-Barriga
12053 (US).

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

B. species, COLOMBIA: F.A. Barkley 38c120 (US).

Begonia trispathulata Group

Begonia trispathulata (A. DC.) WARBURG (Plate 8a,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
(S.S. Tillett 739-585), with mean length of 375 pm. Collar cells
relatively short, number in seed circumference about 15. Other
testa cells polygonal, with undulated anticlinal walls. 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); N. 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 ym 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

mainly short zigzag elevations that obscure the underlying

granular pattern.
Specimens Examined:

B. brevipetala var. brevipetala, VENEZUELA: FJ. 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. trujillensis, VENEZUELA: L. Goldsmith 168 (VT); S.S. Tillett
739-611 (US).

Begonia pectennervia Group

Begonia pectennervia L.B. SMITH & WASSHAUSEN (Plate
8m,n).—Seed Structure: Seeds ellipsoid, 535-590 ym in
length, 350—360 pm in width, mean 565 pm x 350 pm,
length: width ratio 1.6. Collar cells relatively short, 85-160 pm
in length, mean 125 pm, number in seed circumference about
23. Ratio of collar-cell length to seed length 1:4.5. Anticlinal
walls of collar straight to slightly undulated, those of other 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 9a—e,g).—Seed Structure
and Micromorphology: The seeds of B. colombiana Smith &
Schubert, B. killipiana Smith & Schubert, B. ongirostris (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 pm in B. trispathulata to 655 pm Xx 470 pm in B. killipi-
ana. The number of collar cells in the seed circumference var-
ies from about 17 in B. colombiana to 22 in B. killipiana. The
seeds of B. killipiana are characterized by short collar cells that
vary in length from 65 pm to 130 pm, with a mean of 90 pm.
The testa cells of B. killipiana and B. longirostris have a cutic-
ular pattern similar to that of the central field, with short zigzag

1]

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. ki/lipiana 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 9f).—Seed
Structure: Seeds ellipsoid, without distinct differentiation be-
tween operculum and collar, 510-600 pm in length, 295-360
tim 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
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 ym in length, mean
110 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 9/-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
um 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 ym. The cuticular ornamentation

SMITHSONIAN CONTRIBUTIONS TO BOTANY

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 10a-c

The taxon Rossmannia was first described by Klotzsch as a
genus in 1855 and was transferred to sectional level by A. De
Candolle in 1864. The monotypic section is characterized by
pistillate flowers with two-parted placentas and by fruits with
two very small wings and one large, subascending wing up to
40 pm long, covered by two large, persistent bracteoles. 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 10a-—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 uncollapsed, 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 10d-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

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 pm 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 10d,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 175 pm and 380 pm x 185 pm, re-
spectively. The longest ones are found in B. santarosensis
Kuntze, with a mean size of 630 pm x 205 pm and a
length: width ratio of 3.1. The anticlinal walls vary from 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

13

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 ym, 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 lla-d. fig

The section was established by A. De Candolle in 1859 and
was retained as such by subsequent monographers. It includes
about 15 species and occurs in the nothern Andes, mainly 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 1la,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 ym 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. André 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; tes-
ta cells with more pronounced anticlinal walls and locally
sunken anticlinal boundaries.

14

Specimens Examined:

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

OTHER SPECIES OBSERVED (Plate 11b,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 pm x 215 pm in B. pululahua-
na, 450 pm x 200 pm in B. secunda, 590 pm x 225 pm in B.
sodiroi, and 560 ym 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 lle

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 1s restricted to Colombia. The seeds are not very character-
istic and resemble the ordinary type of begonia seed.

Seed Structure and Micromorphology. The seeds of B. hol-
tonis var. holtonis are ellipsoid, with a mean size of 360 pm x
195 um. 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 3878 (US).

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

PLATE I1j-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. var. 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.

SMITHSONIAN CONTRIBUTIONS TO BOTANY

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
tim 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, 13a—c

Section Eupetalum is mainly Andean, with species known
from Ecuador and Peru. The type species, B. geraniifolia
Hooker, has several synonyms.

Smith and Wasshausen (1979, 1986) included the species of
section Huszia in section Eupetalum. The species of former
section Huszia occur in Bolivia, Peru, and Colombia, 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

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 | Héritier, have a mean size of 340 pm x 180 pm and a
length: width ratio of 1.9. The seeds of B. erythrocarpa A. DC.,
B. pastoensis A. DC., and B. pleiopetala A. DC. resemble
those of B. octopetala in size, testal 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 pm 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. cinnabarina, 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. Pringle 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).

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

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

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

tumbezensis, PERU: Weberbauer 7685A (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 pm, with a length: width ratio

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

species B. cinnabarina Hooker, B. hydrophylloides Smith &

bb & & &

15

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 Apteron C. DC.
PLATE 13d,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 pm Xx 210 pm, 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: Sddiro 597 (US, isotype).

2.10. Section Barya (Klotzsch) A. DC.
PLATE 13f-j

Striking characters in section Barya are the presence of erect,
lanceolate tepals in both staminate and pistillate flowers and
unequal stamens united into an elongated column. Begonia
monadelpha Ruiz & Pavon ex A. DC. and B. soror Irmscher
occur in Peru; B. boliviensis A. DC. is known from Bolivia and
Argentina.

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

Seed Structure: Seeds ellipsoid to narrowly ellipsoid,
somewhat irregular in shape. Length 450-555 pm, width
210-240 pm, mean 510 pm x 225 pm, length: width ratio 2.7.
Collar cells elongated, 145-250 pm in length, mean 200 pm,
number in seed circumference about 13. Ratio of collar-cell
length to seed length 1:2.6. Longitudinal anticlinal walls of
collar straight, those of other testa cells straight, curved, or
slightly undulated, with pockets. Operculum obtuse to broadly
nipple-shaped.

16

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 (US).

OTHER SPECIES OBSERVED (Plate 13fg,7).—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: J.J. Wurdack 1627 (US).

3. SECTIONS OCCURRING BOTH IN BRAZILIAN
AND IN ANDEAN REGIONS

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

3.1. Section Pilderia A. DC.
PLATE 13k,n

Klotzsch’s genus Pilderia was reduced to sectional level by
A. De Candolle (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 13k,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 A//art 387 somewhat bigger: 320
um Xx 175 pm. Testa cells polygonal; anticlinal walls straight
and weakly undulated at bases in collection A//lart 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 13/,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. s/eumeri L.B. Smith & B.G. Schubert.

TYPE SPECIES.—Begonia micranthera Grisebach (Plate
13m,o).

Seed Structure: Seeds elliptic. Mean seed size 405 pm x
240 um 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 var. fimbriata. Cuticle with short, un-
dulated striae and with slight double structure in B. micran-
thera var. fimbriata and var. foliosa.

Specimens Examined:

B. micranthera var. fimbriata, ARGENTINA: J. West 8413 (MO,
isotype).
B. micranthera var. foliosa, ARGENTINA: S. Venturi 3457 (US);

J. West 6216 (MO).

B. micranthera var. micranthera, ARGENTINA: Petersen &
Hjerting s.n. (L). BOLIVIA: V.M. Cardenas 4710 (US).

OTHER SPECIES OBSERVED (Plate 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

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 14a,6

This section was draughted by Houghton in 1924 but wasn’t
published by Ziesenhenne until 1974. The section is monotypic
and is restricted to Costa Rica, Guatemala, and Panama. The
section is characterized by a one-celled ovary and a capsule
with three long, hollow, fleshy horns.

TYPE SPECIES.—Begonia heydei C. DC. (Plate 14a,b).

Seed Structure: Seeds ellipsoid, 540-620 pm in length,
255-295 ym 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 11. 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 & Bello 7645 (MO); R.A.
Ocampo 1323 (CR); Stone & Stone 2712 (US).

4.2. Section Gireoudia (Klotzsch) A. DC.
PLATES 14c-n, 15a—c

Gireoudia was described by Klotzsch in 1854 as a genus. It
was reduced to a section by A. De Candolle in 1859. Later,
Gireoudia was considered to be a subsection of section 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,f).

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

1?

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 14d,e,g—n, 15a—c).—The
seeds of all species observed by us conform to the ordinary
seed type. Seeds vary to some extent in size, number of testa
cells, and in micromorphology.

Seed 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 5917 (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 (US).

B. jenmannii, BRITISH GUIANA (=Guyana): B. Maguire & Fan-
shawe 23081 (VU).

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. sartorti, 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 Hexaptera Ziesenhenne
PLATE ISde
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

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 15d,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 McWilliams & 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 3882] (US). MEXICO: R. McVaugh 10266 (US).
NICARAGUA: Williams & R. Molina 42675 (US). PANAMA:
R.L. Liesner 285 (P).

4.4. Section Dissepbegonia Ziesenhenne
PLATE 15fg

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. pal/meri S. Watson
(Barkley and Golding, 1974).

SPECIES OBSERVED.—Unfortunately no seeds were available
of B. cavum. The seeds of B. palmeri are not characteristic and
resemble the ordinary type of begonia seed.

Seed Structure and Micromorphology: Seeds of B. palmeri
have a mean seed size of 355 pm x 205 um, 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.

SMITHSONIAN CONTRIBUTIONS TO BOTANY

Specimen Examined:
B. palmeri, MEXICO: Ynes Mexia 219 (MO).

4.5. Section Podandra A. DC.
PLATE 15h,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 ym x 180
pm, length: width ratio 2.1. Collar cells distinctly elongated,
other testa cells rectangular. Anticlinal walls of collar and testa
cells varying between collections: strongly undulated in Krug
& Urban 1121], undulated to weakly so in Hoffmann 876, and
weakly undulated to almost straight in Sintenis 5341. 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 534] (P).

4.6. Section Weilbachia (Klotzsch & Oersted) A. DC.
PLATE 15k—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 15k—o0).—Seed Structure: Seeds
ellipsoid, varying in size from 320 pm x 195 pm in B. aridicau-
lis Ziesenhenne to 415 pm x 215 pm in B. pustulata Liebmann,
with length: width ratios of 1.6 and 1.9, respectively. Testa
cells irregularly polygonal. Anticlinal walls undulated in most
species but straight to curved in B. purpusii Houghton ex Zie-
senhenne. Operculum nipple-shaped.

NUMBER 90

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 1532] (MO). MEXICO: E.
Matuda 5406 (MO).

B. pustulata, GUATEMALA: H. von Tiirckheim 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 Ruizopavonia A. DC.
PLATES 16, 17a,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-Utley (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 16a,b).

Seed Structure: Seeds ellipsoid, resembling ordinary bego-
nia seed type. Mean seed size of collection Mocquerys 1219
325 pm Xx 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 16c—h,k,/).—
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 ym 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).

. cooperi, CULTIVATED: van Veldhuizen 396 (WAG).

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

. peruviana, PERU: Sandeman 4378 (K).

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

. thiemei C. DC., MEXICO: Martinez Calderon 2258 (US).

. viridiflora A. DC. var. parviflora Smith & Schubert, PERU:
Mexia 04152 (MO, isotype).

SPECIES DIFFERING FROM B. alnifolia (Plates 16j,m—o,

17a,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

SBUaes

w&

20

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 pm 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 B. 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 & Stolze 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 17c—m

The section is characterized in part by three two-parted styles
with linear branches, undivided placentas, and palmately
veined leaves. The species are self-fertilizing herbs.

The section comprises about 12 species. Most species have a
restricted distribution; B. filipes Bentham, B. hirtella Link, B.
humilis Dryander, and B. semiovata Liebmann have a wider
distribution in Central and South America. Begonia hirtella has
been introduced and naturalized in, among other places, South
Africa, Java, and Sri Lanka.

TYPE SPECIES.—Begonia wallichiana Lehman (Plate 17d,g).

Seed Structure: Seeds elliptic, 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
um. 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 omamentation.

Specimens Examined:

B. wallichiana, MEXICO: J.A. Duke M 3682 (MO); L.R. Stan-
ford c.s. 972 (MO).

OTHER SPECIES OBSERVED (Plate 17c,e,fh—m).—The 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.

SMITHSONIAN CONTRIBUTIONS TO BOTANY

Seed Structure and Micromorphology: The seeds of B. fil-
ipes, B. humilis, and B. semiovata are relatively small (e.g., 235
um 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 Sn 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: AH.
Smith 1264 (L); M. Thiébaut 41 (P).

B. hirsuta, COSTA RICA: R. Liesner 4506 (MO). DUTCH GUIANA
(=Surinam): Herb. Splitgerberianum (L).

B. hirtella var. hirtella, BRAZIL: Lourteig 2308 (UV). 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 (US).

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

eral times. According to Baranov and Barkley (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,d).—Type species of
section Begonia.

Seed Structure: Seeds elliptic, 295-420 pm in length,
180-205 pm in width, mean 360 pm x 195 pm, 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 18b,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. cubensis 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. Jérémie 1105 (P).

B. plumieri var. barahonensis, SANTO DOMINGO: Padre Miguel

Fuertes 432 (L).

. retusa, SABA: A.L. Stoffers 3116 (VU).
. rotundifolia, WEST INDIES: Hortus Bot. Liége (cult.); Hortus
Bot. Nancy (cult.).

MAINLY ANDEAN SPECIES OBSERVED (Plate 18/,/,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 of B. altoperuviana A. DC. and B. barrigae Smith
& Schubert also conform to the ordinary seed type and do not
show special characters.

Specimens Examined:

B. altoperuviana, BOLIVIA: Weddell 4556 (P).

B. barrigae, COLOMBIA: cult., van Veldhuizen 872 (WAG).

B. cyatophora, PERU: Ellenberg 735 A (U); Y. Mexia 8128
(MO).

B. guaduensis, GUYANA: Maas & Westra 3877 (U). PANAMA:
C.E. Smith Jr. & H. Morgan Smith 3272 (US).

B. portillana, MEXICO: Dunn, Le Doux, & Torke 21820 (MO).

wd

Begonia cucullata—Begonia fischeri Group

Begonia cucullata WILLDENOW (Plate 19a—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 um, 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
um, 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

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: 7T.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.
Mosén 1598 (P). PARAGUAY: Jorgensen 3473 (US). URU-
GUAY: HH. Bartlett 21359 (P).

OTHER SPECIES OBSERVED (Plate 19e—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 pm in B. subvillosa var. leptotricha (C.
DC.) Smith & Wasshausen to 430 pm in B. descoleana. They
also may show some differences in testal pattern, e.g., B. 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-
mark c.s. 100258 (P).

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 (P).

B. meridensis, VENEZUELA: Holst & Liesner 3159 (MO).

B. per-dusenii, BRAZIL: L.B. Smith, Klein, & Schnorrenberger
11728 (K).

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

SMITHSONIAN CONTRIBUTIONS TO BOTANY

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 18n).—Seed Structure
and Micromorphology: The seeds of this species conform to
the ordinary seed type and cannot be linked to either of the
above-described groups. The mean seed size is 555 pm x 255
hm, 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, 2la-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, 1960) and the
monotypic section Quadriperigonia Ziesenhenne, which was
eliminated by the synonymy of the type species, B. abaculoides
Ziesenhenne, with B. boissieri A. DC. (Smith and Wasshausen,
1983).

The species of this section are very diverse. Some show a
close resemblance to species of Begonia, others are similar to
species of Eupetalum, Ruizopavonia, and some other sections
with bifid placentas. The section is characterized by anthers
that are globose or obovoid and are much shorter than the 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,a).

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, 21la—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 ym 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 (WAG).

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).

. maynensis, BRAZIL: Prance c.s. 7409 (U).

. oellgaardii, ECUADOR: M.A. Baker 6396 (US).

. olbia, BRAZIL: cult., van Veldhuizen 434 (WAG).

. peltata var. peltata, MEXICO: cult., Hort. Bot. Gent, B.K.
Boom 14288 (L).

. Sandtii, MEXICO: cult., Ziesenhenne s.n.

. uniflora, MEXICO: J. Roybal 647 (US).

. wollnyi, BOLIVIA: cult., van Veldhuizen 435 (WAG).

SBaBDd

Bwds

6.4. Section Donaldia (Klotzsch) A. DC.
PLATE 21h-0

This section, comprising seven species, is characterized in
part by pinnate leaves and by male flowers with two
(sometimes four) tepals and ellipsoid anthers that are about as
long as the filaments. No seeds were available for B. 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 pm x 190
pm, 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. u/mifolia 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

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
um; 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 B.
fruticosa.

The mean number of collar cells in the seed circumference is
mostly between 10 and !2; 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 ym 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

SMITHSONIAN CONTRIBUTIONS TO BOTANY

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

Seed structure in section Hydristyles is quite diverse. Seed
micromorphology provides arguments for the inclusion of sec-
tion Warburgina in section Hydristyles. The seeds of B. comata
resemble seeds of species of section Hydristyles, like B. andina
and B. unduavensis, in their elongated testa cells with strongly
undulated walls.

The seeds of section Gobenia are characterized by an 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. bakeri (=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

Pas

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

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 Léveillé 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. mu/tangula 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, 1.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

SMITHSONIAN CONTRIBUTIONS TO BOTANY

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 (=B.
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

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,

ad

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).

Literature Cited

Baranov, A.I., and F.A. Barkley
1972. Some Nomenclatural Changes in the Sections of Begonia L. Phyto-
logia, 24:155-156.
1974. The Sections of the Genus Begonia. 28 pages. Boston: Northeastern
University. [Distributed as cyclostyled copies. ]
Barkley, F.A., and J. Golding
1974. The Species of the Begoniaceae. Second edition, iv+ 144 pages. Bos-
ton: Northeastern University.
Bouman, F., and A. de Lange
1983. Structure, Micromorphology of Begonia Seeds. The Begonian,
50:70-78, 91.
Brade, A.C.
1945. Begonias novas do Brasil, III, IV. Rodriguésia, 9(18):17—22, 23-34.
1957. Begoniaceae. /n Flora do Itatiaia, I. Rodriguésia, 32(20):151-166.
Burt-Utley, K.
1984. Notes on Mesoamerican Begonia. Phytologia, 54(7):486—489.
1985. A Revision of Central American Species of Begonia Section Gire-
oudia (Begoniaceae). Tulane Studies in Zoology and Botany, 25(1):
1-131.
1990. New and Noteworthy Species in Begonia Section Gireoudia (Bego-
niaceae) from Mexico. Brittonia, 42(1):38—-46.
Candolle, A. de

1859. Mémoire sur la famille des Bégoniacées. Annales des Sciences Na-
turelles, series 4 (Botany), 11:93-149.
1861. Begoniaceae. Jn C.F.P. von Martius, Flora Brasiliensis, 4(1):

338-396. Monanchii (=Miunchen) and Lipsiae (=Leipzig).
1864. Ordo CLXXII, Begoniaceae. In Prodomus Systematis Naturalis
Regni Vegetabilis, 15(1):266—408. Paris.
Doorenbos, J., M.S.M. Sosef, and J.J.F.E. de Wilde

1998. The Sections of the Genus Begonia, Including Descriptions, Keys
and Species Lists. Wageningen Agricultural University Papers,
98(2): 1-266.

Golding, J.

1992. Interim Supplement to Begoniaceae, Part I: Illustrated Key; Part II:
Annotated Species List by L.B. Smith et al. 34 pages. [Personal pub-
lication. ]

Irmscher, E.

1925. Begoniaceae. /n A. Engler and K. Prantl, Die natirlichen Pflanzen-
familien, second edition, 21:548-588. Leipzig: W. Engelmann.

1949. Beitrage zur Kenntnis der Begoniaceen Siidamerikas. Botanische
Jahrbiicher, 74:569-632.

1953. Systematische Studien tiber Begoniaceen des Tropischen Siidameri-
kas, besonders Brasiliens. Botanische Jahrbiicher, 76:1—102.

1960. Fam. Begoniaceae, Schiefblattgewachse. /n Fritz Encke, editor,

Parey’s Blumengartnerei, second edition, pages 67-98. Berlin: P.
Parey.
Jayasuriya, A.H.M.
1983. Begoniaceae. Jn M.D. Dassanayake and F.R. Fosberg, editors, A Re-
vised Handbook to the Flora of Ceylon, 4:137-152. New Dehli:
Amerind Publishing Company.
Keraudren-Aymonin, M.

1983. Famille 144, Bégoniacées. In Flore de Madagascar et des Comores:
Plantes Vasculares, pages 1-108. Paris: Muséum National d’ His-
toire Naturel.

Klotzsch, J.F.
1855. Begoniaceen-Gattungen und Arten. Abhandlungen Konigliche

Akademie Wissenschaften (Berlin), 1854:1-135.

28

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):489-495.
Seed Micromorphology of the Genus Begonia in Africa: Taxonomic
and Ecological Implications. Wageningen Agricultural University
Papers, 91(4):1-82.
Mabberley, D.J.
1989. The Plant-Book. xii+706 pages. Cambridge: Cambridge University
Press.
Miller, C.
1857. 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):139-150.
Pil, L. van der
1972. Principles of Dispersal in Higher Plants. Second edition, xit+161
pages. Berlin: Springer-Verlag.
Smith, L.B.
1973. Begonia of Venezuela. Phytologia, 27:209-227.
Smith, L.B., and B.G. Schubert

1992.

1941. Revision de las especies Argentina del género Begonia. Darwini-
ana, 5:78-117.

1946. The Begoniaceae of Colombia. Caldasia, 4(16):1-138; 4(17):
77-107; 4(18):179-209.

1955. Studies in the Begoniaceae, IV. Journal of the Washington Academy

of Sciences, 45(4):110-114.
Smith, L.B., and D.C. Wasshausen

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

1983. Notes on Begoniaceae—1. Phytologia, 52(7):441-451.
1984. Notes on Begoniaceae—III. Phytologia, 54(7):465—473.
1986. 133, Begoniaceae. Flora of Ecuador, 25:1-66.

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

1986. Begoniaceae, Part I: Illustrated Key; Part II: Annotated Species List.

Smithsonian Contributions to Botany, 60: 584 pages.
Sosef, M.S.M.

1994. 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.

1946. Duas novas espécies Brasileiras de Begonia L. Arquivos de Botanica

do Estado de Sao Paulo, 2(3):61.
Warburg, O.
1894. Begoniaceae. /n A. Engler and K. Prantl, Die natiirlichen Pflanzen-
familien, 3(6a):121—150. Leipzig.

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

1985. Studies in Begoniaceae, II. Wageningen Agricultural University Pa-
pers, 84(3):1-129.
Studies in Begoniaceae, III. Wageningen Agricultural University
Papers, 91(4):1-151.
Ziesenhenne, R.

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

1974. Three New Begonia Sections. The Begonian, 41(1):11-13.

1992.

NUMBER 90

PLATE 1.—Seeds of sections Trachelocarpus and Solananthera: a, B. herbacea (Lisedecceales s.n.), X125; b, B.
herbacea var. ellipticifolia (Ule 4240), x 110, c, detail testa, x 500; d, B. solananthera (cult.), x 150; e, B. depau-
perata (Campos Goer 140), x 130; f, B. lanceolata (Smith & Pereira 15343), x100; g, B. radicans (Luederwaldt

s.n.), X80; h, B. integerrima (Pereira 606), x95.

29

30

SMITHSONIAN CONTRIBUTIONS TO BOTANY

i ('
\

DYN

PLATE 2.—Seeds of sections Trendelenburgia and Scheidweileria: a, B. fruticosa (Martins 8380), x 100, f, detail
testa, x 490; b, B. pentaphylla (Maguire c.s. 44596), X120, c, detail testa, x480; d, B. luxurians (Hoehne 2370),
x 130; e, B. digitata (Martinelli & Maas 3271), x120; g, B. incisoserrata (Hatschbach & Kummran 45532),
x 170; h, B. parviflora (Killip 7837), x210.

NUMBER 90

PLATE 3.—Seeds of sections Ewaldia and Enita: a, B. lobata (Hatschbach 30073), x 130; b, B. scharffii (Pala-
cios-Cuezzo 2930), x 160; c, B. tomentosa (Brade 18572), x 160; d, B. rigida (ABS Seed Fund), x 190; e, B. con-
volvulacea (Schenck 858), x120; f, B. epibaterium (Scott Mori c.s. 12856), 140; g, B. fagifolia (Brade 19144),
x 120; h, B. glabra var. glabra (Irwin c.s. 54738), x 180, k, detail chalaza, x280; j, B. glabra var. glabra (Laurito
8172), x 120.

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, f, seed, x 150; d, B. coccinea
(Burchell 219A), detail testa, x860, g, seed, x 120; e, B. grisea (St. Hilaire B 2027), x95; h, B. angulata var.
angulata (Hatschbach 8831), x120; j, B. itaguassuensis (Lourteig 3236), x 150; k, B. dichotoma (Boone-Hahn
25), 140; /, B. acida (cult., Liége), x 180; m, B. paranaensis (Hatschbach 8941), x110; n, B. olsoniae (Pereira
307), x110.

NUMBER 90

PLATE 5.—Seeds of sections Pritzelia, Philippomartia, Steineria, and Bradea: a, B. bradei (cult.), x 140; b, B.
hispida (Bailey & Bailey 710) x130; c, B. membranacea (Curran 170), x200; d, B. leptophylla (Mo 4331),
x170, e, detail chalaza, x440; f B. hookerana (Occhioni 4788), x 140, j, 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;
1, B. oxyphylla (Inh. Vien s.n.), x190; m, B. rufosericea (Oswaldo Hanro s.n.), X160; n, B. bidentata (Peckolt
75), x 160.

33

34

SMITHSONIAN CONTRIBUTIONS TO BOTANY

SUDA
ANY

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Vi

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Vis

PLATE 6.—Seeds of sections Bradea, Tetrachia, Gaerdtia, Latistigma, and Pereira: a, B. dentatiloba (L.B. Smith
1935), x 160; 6, B. parvifolia (d'Alleizette s.n.), 130; c, B. egregia (Santos Lima s.n.), X120, g, detail testa,
720; d, B. corallina (Boone-Hahn 114), x125; e, B. maculata (Maas & Carauta 3149), x115, f detail testa,
x 1140; h, B. undulata (Gaudichaud 1067), x 140; j, B. aconitifolia (Glaziou 13389), x150; k, B. leathermaniae
(Moraes 1056), x 180, n, detail testa, x560; /, B. platanifolia (Hatschbach 46298), x150; m, B. edmundoi
(Pereira 366), x 140.

NUMBER 90

ey Ef
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PLATE 7.—Seeds of section Casparya: a, B. urticae (Harling et al. 20465), x105, b, detail testa, x340; c, B.
Juchsiiflora (Scott Hoover 515), detail testa, x620, f seed, x 120; d, B. urticae (Bohlin 975), x120; e, B. longi-
rostris (Harling & L. Andersson 11608), x 130; g, B. gamolepis (Killip & A.C. Smith 16037), x 130; h, B. ferrug-
inea (Langenheim 3387), x85; j, B. ferruginea var. dilatata (Garcia-Barriga 12053), x 115, k, detail testa, x370.

32

36

SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE 8.—Seeds of section Casparya: a, B. trispathulata (Tillett 739-585), x 130, 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), x125; f, B. mariae (Goldsmith 163), x130; h, B. formosissima (Ruiz-Teran &
Figueiras 9306), x90, j, detail testa, x400; k, B. lipolepis (Goldsmith 167), x110; [, B. toledana (Steyermark &
Dunsterville 100604), x125; m, B. pectennervia, seed (Holm-Nielsen 26762), x125, n, detail testa (Holm-
Nielsen 26438), x620.

NUMBER 90

PLATE 9.—Seeds of section Casparya: a, B. colombiana (Schultes & Villarreal 7758), x120; 6, B. killipiana
(Scott Hoover 27), x95, c, detail testa, x280; d, B. trispathulata (Steyermark 103480), detail testa, x550, g, seed,
x 140; e, B. longirostris (Lugo 4699), x115; f, B. antioquensis (Luteyn 12265), x140; h, B. hexandra (Core
1500), x110; j, B. diversistipulata (Giacometto 11) x150; k, B. umbellata (Killip & Hazen 9165), x105; 1, B.
montana (Funck & Schlim 1044), x115; m, B. formosissima (Lopez-Figueiras & Dugarte 29409), x100; n, B.
raimondi (Raimondi 2982), x85.

37

38

SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE 10.—Seeds of sections Rossmannia, Hydristyles, and Warburgina: a, B. rossmanniae (Holguer Lugo S.
4824), x170, b, operculum, x440 (Holguer Lugo S. 4824), c, detail testa, x510 (Vogelmann c.s. 1297); d, B. san-
tarosensis (s.n.), X150, e, detail testa, x400; f aff. B. bridgesii (Dereims s.n.), 150; g, B. subcaudata (Beck
9253), x 160; h, B. juntasensis (Moore, Salazar, & Smith 8601), x 180; j, B. unduavensis (Mandon 1089), x 150;
k, B. andina (Williams 1566), x 140; /, B. comata (Beck 12651), x 160.

NUMBER 90

PLATE 11.—Seeds of sections Gobenia, Meionanthera, Lepsia, and Tittelbachia: a, B. maurandiae, seed (Camp
E 4974), x130, d, detail chalaza (André 3315), x260; b, B. pululahuana (Davis 500) x115; c, B. secunda (Gen-
try & Shupp 26638), x150; e, B. holtonis, detail testa (Uribe Uribe 3878), x590, h, seed (Holton 725), x170; f,
B. ynesiae (Mexia 7706), x 115; g, B. sodiroi (Holm-Nielsen & Jeppesen 1276), 110; j, B. foliosa var. australis
(Matthias & Taylor 5905), x200; k, B. foliosa var. putzeysiana (Killip & Smith 19817), x 120; 1, B. foliosa var.
rotundata (McDougal & Roldan 3540), x 145; m, B. microphylla (Breteler 4643), x125; n, B. fuchsioides var.
fuchsioides (Killip & Smith 20552), x 140.

40

SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE 12.—Seeds of section Eupetalum, including former section Huszia: a, B. octopetala (Holm-Nielsen c.s.
3404), x190, c, detail testa, x790; 6, B. pastoensis (Lehman 5404) detail cuticle, x3340, d, seed, x 180; e, B.
erythrocarpa (Wasshausen & Salas 1194), x 180; f, B. pleiopetala (Buchtien 653), x 150; g, B. macbrideana
(Weberbauer 2011), x 130; h, B. geraniifolia (Lourteig 3117), seed, x 170, k, detail chalaza, x350; j, B. geranii-
folia (Dowbey s.n.), detail testa, x690; J, B. cinnabarina (de Michel 16), x160; m, B. hydrophylloides (Idrobo &
Evans Schultes 560), x200; n, B. serotina (Camp E 3716), x200; 0, B. pearcei (van Veldhuizen 580), x 170.

NUMBER 90

PLATE 13.—Seeds of sections Eupeta/um (including former section Huszia), Apteron, Barya, Pilderia, and Aus-
trales: a, B. tumbezensis (Weberbauer 7685A ), X220; b, B. monophylla (Pringle s.n.), X 190; c, B. novogranatae
(Dawe 272), x190; d, B. exalata (Sddiro 597), x190, e, cuticle, x 1970; f, B. boliviensis (Hawkes c.s. 3620),
detail testa, x 740, g, seed, x 170; h, B. monadelpha (Weberbauer 6714), x120; j, B. soror (Wurdack 1627),
x 130; k, B. buddleiifolia (Holguer Lugo S. 5042), x220, n, detail cuticle, x2380; /, B. tafiensis (Venturi 3093),
x 140; m, B. micranthera var. micranthera (Petersen & Hjerting s.n.), X 160; 0, B. micranthera var. foliosa (West
6216), detail testa, x550.

41

SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE 14.—Seeds of sections Urniformia and Gireoudia: a, B. heydei (Haber & Bello 7645), x115, 6, detail
testa, x870; c, B. plebeja (Taylor 17305), x170, f, detail cuticle, x2460; d, B. jenmannii (Maguire & Fanshawe
23081), X190; e, B. multinervia (van Veldhuizen 661), X180; g, B. sericoneura (van Veldhuizen 392), detail cuti-
cle, x2710, k, seed, x 180; A, B. urophylla (van Veldhuizen 655), x140; j, B. sartorii (Bourgeau 2100), x150; I,
B. crassicaulis (Steyermark s.n.), X160; m, B. involucrata (Standley 34241), x190; n, B. conchifolia (Wilbur
24349), x 160.

NUMBER 90

PLATE 15.—Seeds of sections Gireoudia, Hexaptera, Dissepbegonia, Podandra, and Weilbachia: a, B. barkeri
(Smith 690), x 160; b, B. cardiocarpa (Utley 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, x 560, g, seed, x 190; h, B. decandra (Krug & Urban 1121), x 180, j, 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), x145; 0, B. alice-clarkiae (van Veldhuizen 497), x 170.

43

44

SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE 16.—Seeds of section Ruizopavonia: a, B. alnifolia (Mocquerys 1219), x 180, b, detail cuticle, x2620; c,
B. peruviana (Sandeman 4378), detail testa, x400, f seed, x 190; 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 180; j, B. udisylvestris (Burger & Stolze 5250), detail testa, x490, m, seed,
x115; /, B. seemanniana (Seemann 1661), x200; n, B. suprafastigiata (Weberbauer 7907), x 145; 0, B. cuatreca-
siana (Forrero-Jaramillo 2403), x 180.

NUMBER 90

PLATE 17.—Seeds of sections Ruizopavonia and Doratometra: a, B. estrellensis, x130 (Zamora c.s. 512), b,
x 145 (Liesner 1023); c, B. steyermarkii (Cowan & Soderstrom 1841), x200; d, B. wallichiana (Stanford c.s.
972), detail cuticle, x2610, g, seed, x 180; e, B. prieurii (Irwin c.s. 48113), detail testa, x420, f seed, x200; h, B.
filipes (Thiébaut 41), x240; 7, B. humilis (Egger 1404), x210; k, B. tonduzii (Grayum 8132), x220; 1, B. hirsuta
(Herb. Splitgerberianum), x190; m, B. hirtella (Lourteig 2308), x210.

45

46

SMITHSONIAN CONTRIBUTIONS TO BOTANY

PLATE 18.—Seeds of section Begonia: a, B. obliqua (Duss 973), x170, d, detail testa, x 1890; 6, B. rotundifolia
(cult., Liége), x 180; c, B. glandulifera (Van Steenis 20304), x200; e, B. plumieri var. barahonensis (Miguel
Fuertes 432), detail testa, x 1150, h, seed, x 160; £ B. odorata (Morton 5066), x 160; g, B. retusa (Stoffers 3116),
x 200; j, B. guaduensis (Maas & Westra 3877), X150; k, B. cubensis (Ziesenhenne s.n.), x 160; I, B. cyatophora
(Mexia 8128), x 180; m, B. altoperuviana (Weddell 4556), 170; n, B. organensis (Sucre c.s. 3005), x 130.

NUMBER 90

PLATE 19.—Seeds of section Begonia: a, B. cucullata var. cucullata, x125 (Irwin c.s. 19961), b, x125 (Bartlett
21359), c, detail cuticle, x 1730 (Bartlett 21359); d, B. cucullata var. arenosicola (Pedersen 10232), x 190; e, B.
fischeri var. fischeri (Steyermark & Rabe 96605), x100, f detail testa, x470; g, B. alchemilloides (Irwin c.s.
34478), x190; h, B. balansae (Balansa 3281), x150; j, B. descoleana (Hatschbach 9944), x160; k, B. fischeri
var. klugii (Klug 3389), x115; 1, B. per-dusenii (Smith, Klein, & Schnorrenberger 11728), x190; m, B. subvil-
losa var. leptotricha (Fiebrig 5354), x 180.

47

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; f, B. boissieri (van Veldhuizen 747), x180; g, B. ludwigii (van Veldhuizen 618), x 140;
j, B. sandtii (Ziesenhenne s.n.), X170; k, B. angustiloba (Diguet s.n.), x 190; 1, B. falciloba (Bourgeau 649),
x170; m, B. ignea (Pittier & Durand 1299), x 140; n, B. uniflora (Roybal 647), x 160.

NUMBER 90

PLATE 21.—Seeds of sections Knesebeckia and Donaldia: a, B. oellgaardii (Baker 6396), x 190; 6, B. maynensis
(Prance c.s. 7409), X220, c, detail testa, x780; d, B. olbia (van Veldhuizen 434), detail testa, x610, g, seed,
x 140; e, B. wollnyi (van Veldhuizen 435), x240; f, B. dichroa (Ziesenhenne s.n.), x 140; h, B. ulmifolia (Hekking
1428), x210, k, detail chalaza, x420; j, B. dasycarpa (Glaziou 15388), detail testa, x 760, /, seed, x 160; m, B.
chaetocarpa var. chaetocarpa (Kuntze s.n.), X210; n, B. chaetocarpa var. glabriflora (Rusby 690), x 180; 0, B.
bangii (Bang 406), x 180.

49

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“Literature Cited.” For botany, the long form (taxon, author,
abbreviated journal or book title, volume, page, year, with no
reference in “Literature Cited”) is optional.

Text-reference system (author, year:page used within the text,
with full citation in “Literature Cited” at the end of the text) must be
used in place of bibliographic footnotes in all Contributions Series
and is strongly recommended in the Studies Series: “(Jones,
1910:122)" or “...Jones (1910:122).” If bibliographic footnotes are

required, use the short form (author, brief title, page) with the full
citation in the bibliography.

Footnotes, when few in number, whether annotative or biblio-
graphic, should be typed on separate sheets and inserted immedi-
ately after the text pages on which the references occur. Extensive
notes must be gathered together and placed at the end of the text in
a notes section.

Bibliography, depending upon use, is termed “Literature Cited,”
“References,” or “Bibliography.” Spell out titles of books, articles,
journals, and monographic series. For book and article titles use
sentence-style capitalization according to the rules of the language
employed (exception: capitalize all major words in English). For
journal and series titles, capitalize the initial word and all subsequent
words except articles, conjunctions, and prepositions. Transliterate
languages that use a non-Roman alphabet according to the Library
of Congress system. Underline (for italics) titles of journals and
series and titles of books that are not part of a series. Use the
parentheses/colon system for volume (number):pagination:
“40(2):5-9.” For alignment and arrangement of elements, follow the
format of recent publications in the series for which the manuscript is
intended. Guidelines for preparing bibliography may be secured from
Series Section, S| Press.

Legends for illustrations must be submitted at the end of the
manuscript, with as many legends typed, double-spaced, to a page
as convenient.

Illustrations must be submitted as original art (not copies)
accompanying, but separate from, the manuscript. Guidelines for
preparing art may be secured from the Series Section, S| Press. All
types of illustrations (photographs, line drawings, maps, etc.) may be
intermixed throughout the printed text. They should be termed
Figures and should be numbered consecutively as they will appear
in the monograph. If several illustrations are treated as components
of asingle composite figure, they should be designated by lowercase
italic letters on the illustration; also, in the legend and in text
references the italic letters (underlined in copy) should be used:
“Figure 9b.” Illustrations that are intended to follow the printed text
may be termed Plates, and any components should be similarly
lettered and referenced: “Plate 9b.” Keys to any symbols within an
illustation should appear on the art rather than in the legend.

Some points of style: Do not use periods after such abbrevia-
tions as “mm, ft, USNM, NNE."” Spell out numbers “one” through
“nine” in expository text, but use digits in all other cases if possible.
Use of the metric system of measurement is preferable; where use of
the English system is unavoidable, supply metric equivalents in
parentheses. Use the decimal system for precise measurements and
relationships, common fractions for approximations. Use day/month/
year sequence for dates: “9 April 1976." 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) abstract, (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 manuscript is submitted.

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