Botanical Studies (2007) 48: 465-473.

*

Corresponding author: E-mail: bopeng@sinica.edu.tw.

INTRODUCTION

Our ongoing botanical inventory in recent years in

the limestone areas in Guangxi Zhuangzu Autonomous

Region, China has resulted in the discovery of a dozen

new taxa of Begonia in sect. Coelocentrum (Ku et al.,

2004; Peng et al., 2005a, 2005b; Liu et al., 2005; Fang

et al., 2006; Ku et al., 2006; Peng et al., 2007) and a new

species in sect. Diploclinium (Peng et al., 2006). A total

of 38 species and two additional varieties are recognized

for Begonia sect. Coelocentrum in the Flora of China (Gu

et al., 2007). In this paper we report the finding of another

new species, B. bamaensis, found in karst caves in western

Guangxi, China.

MATERIALS AMD METHODS FOR CRYO

SCANNING ELECTRON MICROSCOPY

Fresh leaves of Begonia bamaensis and B. cirrosa were

dissected and loaded on stub. The samples were frozen

by liquid nitrogen slush, and then transferred to sample

preparation chamber at -160¢XC. After 5 minutes, when the

temperature raised to -130¢XC, the samples were fractured.

The samples were etched 10 minutes at -85¢XC. After

coating at -130¢XC, the samples were transferred to SEM

chamber and observed at -160¢XC in cryo scanning electron

microscope (FEI Quanta 200 SEM/Quorum Cryo System

PP2000TR FEI).

NEW SPECIES

Begonia bamaensis Yan Liu & C.-I Peng, sp. nov.¡X

TYPE: CHINA. Guangxi Zhuangzu Autonomous

Region, Bama Yaozu Zizhixian, 24¢X18¡¦05" N, 107¢X05¡¦

58" E, on soil and limestone rock at entrance and inside

(near opening at the rear end) of a gigantic karst cave,

Baimodong (literally, Hundred Devils¡¦ Cave), abundant.

19 May 2007, Ching-I Peng 21087 (holotype: IBK;

isotype: HAST), accompanied by Hai-Shan Gao, Kuo-

Fang Chung and Ming-Chao Yu. ¤Ú°¨¬î®ü´Å

Figures 1, 2

Begonia bamaensis similis B. cirrosae L.B. Smith

& D.C. Wasshausen, a qua differt foliis supra dense

setulosis vel hispidulosis et inter nervos albo-vittatis vel

albo-maculatis, stipulis subtus glabris vel secus costam

sparse pilosis, pedunculis pilosis vel sparse pilosis, tepalis

exterioribus floris staminati 7-14.5 ¡Ñ 7-13.5 mm, ovario

albido-piloso vel rubello-piloso, capsula 7-12 mm longa,

capsulae ala abaxiali distincte curvata versus unum

laterem.

Begonia bamaensis (sect. Coelocentrum, Begoniaceae),

a new species from limestone areas in Guangxi, China

Yan LIU

1

, Shin-Ming KU

2

, and Ching-I PENG

2,

*

1

Guangxi Institute of Botany, Guangxi Zhuangzu Autonomous Region and the Chinese Academy of Sciences, Guilin

541006, China

2

Herbarium (HAST), Research Center for Biodiversity, Academia Sinica, Nangang, Taipei 115, Taiwan

(Received May 30, 2007; Accepted August 21, 2007)

ABSTRACT.

Begonia bamaensis Yan Liu & C.-I Peng, a new species of sect. Coelocentrum from Guangxi

Zhuangzu Autonomous Region, China, is described and illustrated. Its somatic chromosome number (2n =

30) is here reported. Begonia bamaensis is somewhat similar to B. cirrosa L.B. Smith & D.C. Wasshausen,

differing in the leaves adaxially densely setulose or hispidulous and adorned with white bands or white

patches between major veins; stipules abaxially glabrous or with few hairs along midrib; peduncle pilose or

sparsely so; staminate flower with outer tepals 7-14.5 ¡Ñ 7-13.5 mm; ovary whitish or reddish pilose; capsule

7-12 mm long, and abaxial wing of capsule distinctly curved on one side. SEM micrographs of leaves of

B. bamaensis revealed prominently elevated stomata complex, which is unique for the genus Begonia. Like

many congeners in sect. Coelocentrum, B. bamaensis is a handsome species with variegated leaves. It has a

restricted distribution, currently known only from two nearby karst caves in western Guangxi.

Keywords: Begonia bamaensis; Begonia cirrosa; Begonia morsei; Begonia bonii; Begoniaceae; China;

Chromosome number; Guangxi; Limestone flora; New species; Rare species; sect. Coelocentrum; Stomata

complex.

TAxONOMY

466

Botanical Studies, Vol. 48, 2007

Figure 1. Begonia bamaensis Yan Liu & C.-I Peng. A, Habit; B, Leaf margin; C, C¡¦, Portion of leaf, showing indumentum on

adaxial and adaxial surfaces; D, Stipules; E, Inflorescence; F, Bracts; G, Staminate flower, showing ciliate margin and densely pilose

abaxial surface; G¡¦, Staminate flower, face view; G¡¦¡¦, Staminate flower, back view; H, H¡¦, stamens; I, Carpellate flower, face view; I¡¦,

Carpellate flower, side view; J, K, K¡¦, Styles and stigmas; L, Capsule; M, Serial cross sections of fruit, showing parietal placentation

and curved abaxial wing. All from the living plant (Peng 18752-A) cultivated in the experimental greenhouse.

LIU

et al. ¡X

Begonia bamaensis

, a new species from China

467

Figure 2. Begonia bamaensis. A, Habit; B, Cultivated plant; C, Leaf; D, Portion of leaf, showing abaxial surface and margin; E,

Staminate flower, face view; F, Staminate flower, back view; G, Staminate flower, side view; H, Styles and stigmas; I, Carpellate

flower, face view; J, Carpellate flower, side view; K, Middle cross section of an ovary; L, Capsule; M, Seed SEM micrograph.

468

Botanical Studies, Vol. 48, 2007

Herbs monoecious; epipetric; perennial; rhizomatous.

Rhizome 3-15 cm or longer, 9-17 mm thick, internodes

(3-)5-7(-10) mm long, brown, reddish brown or greenish

brown, villous near petiole bases and leaf scars. Stipules

caducous, ovate-triangular, 7-10 mm long, 5-13 mm

wide, greenish or reddish-hyaline, herbaceous, weakly

keeled or not keeled, abaxially glabrous or with few hairs

along midrib, margin serrulate-ciliolate or subentire,

apex aristate, arista 0.5-4 mm long, hair-like. Leaves 2-9,

alternate, simple, asymmetric, unlobed, broadly ovate

or suborbicular, base deeply cordate, margin crenate-

denticulate and ciliolate, apex shortly acuminate, or acute,

rarely obtuse, variable in size, (7-)10-25(-32) cm long

(basal lobes included), (5.7-)9-20(-30) cm wide, adaxial

surface green, usually adorned with white bands or white

patches between major veins, greenish on abaxial surface,

texture papery, surface rugose or rugulose, adaxially

densely setulose to hispidulous (Figure 3A) trichomes

0.2-0.6 mm long, whitish-hyaline), abaxially pilose-

tomentulose to tomentose, pronounced on veins (Figure

3C); venation basally 7-palmate, midrib distinct, veins

pinnate along midrib, with 1-3 major lateral veins on each

side, other primary veins branching dichotomously or

nearly so, tertiary veins reticulate and weakly percurrent,

Table 1. Comparison of Begonia bamaensis, B. bonii, B. cirrosa and B. morsei.

B. bamaensis

(Figures 1, 2)

B. bonii (Figure 5) B. cirrosa (Liu et al.,

2005: Figures 5, 6)

B. morsei (Liu et al.,

2005: Figure 7)

Stipule

Abaxially glabrous or

with few hairs along

midrib

Pubescent

throughout abaxial

surface

Pubescent throughout

abaxial surface

Pubescent along midrib

Leaf

Size (cm)

(7-)10-25(-32) ¡Ñ

(5.7-)9-20(-30)

(5.2-)7-11 ¡Ñ

(4.6-)5-7.2

(8-)11-18(-20) ¡Ñ

(6-)9-14(-17)

ca. 5-9 ¡Ñ 4-7

Indumentum

Densely setulose or

hispidulous (Figure

3-A, C)

Moderately setulose Sparsely to moderately

pilose or pilose-setose

(Figure 3-B, D)

Densely pilose-setulose

Maculation

(adaxial surface)

Adorned with white

maculation in

intercostal area

No maculation

No maculation

Adorned with a broad

whitish ring between

leaf center and margin

Stomata complex Markedly elevated

(Figures 3-E, G; 4-A,

B)

Not observed

Nearly flat (Figure 3-F, H) Not observed

Peduncle

Pilose or sparsely

so, glabrous in

poorly developed

inflorescences

Sparsely pilose or

subglabrous

Densely villous or hispid-

villous

Glabrous

Staminate flower

Outer tepals 7-14.5 ¡Ñ 7-13.5 mm,

abaxially pilose

8-10 ¡Ñ 7-10 mm 7-17 ¡Ñ 7-22 mm

6¡V10.5 ¡Ñ 6.5-10 mm

Androecium

Symmetry

Zygomorphic

Actinomorphic Zygomorphic

Unknown (probably

zygomorphic)

Filaments

Slightly fused at base Slightly fused at

base

Nearly free

Fused at base into an

androphore 0.7-1.25

mm

Capsule

Size (mm)

7-12 ¡Ñ 5-7

ca. 8 ¡Ñ 4-5

13-19 ¡Ñ 7-9

6.5-9 ¡Ñ 3.5-4.5

Indumentum Hirsute-pilose or

villous-pilose

Glabrous or nearly

so

Villous-setose or hispid-

setose

Glabrous or nearly so

Abaxial wing Markedly curved toward

one side

Straight

Straight

Straight

Distribution

Sounthern China

Northern Vietnam Sounthern China

Sounthern China

LIU

et al. ¡X

Begonia bamaensis

, a new species from China

469

Figure 3. S ca nning

e le ctro n mi cros c ope

(S EM) micrographs of

folilar trichom es and

stomata of Begonia

bamaensis (A, C, E,

G) and B. cirrosa (B,

D, F, G). A, B. Leaf

upper surface; C,

D, E, F, Leaf lower

surface; G, H, Stomata

complex. Scale bar =

1 mm (A, B, C, D);

500 £gm (E, F); 50 £gm

(G, H).

470

Botanical Studies, Vol. 48, 2007

margin denticulate and ciliate (cilia with a minute,

glandular tip), apex rounded, obtuse or acute, 2-6 mm

long, 1.5-5 mm wide, greenish or brownish, membranous.

Staminate flowers: pedicel 8-20 mm long, glabrous or

pilose, erect or ascending; tepals 4, outer 2 broadly ovate

or suborbicular, base rounded or slightly cordate, margin

entire, eciliate or sometimes ciliate on first flower, apex

rounded, 7-14.5 mm long, 7-13.5 mm wide, pinkish, white

or greenish white, abaxially pilose (trichomes reddish or

whitish); inner 2 tepals obovate, narrowly obovate, elliptic

or oblanceolate, base cuneate, margin entire, eciliate, apex

obtuse or rounded, 6-10 mm long, 2.5-5 mm wide, white,

glabrous; androecium zygomorphic, subglobose, stamens

forming a divergence angle of 70-90¢X to major veins,

minor veins reticulate, all veins on abaxial surface

prominently raised; petiole terete, (5-)9-22(-26) cm

long, 3-7 mm thick, brownish or brownish red, hirsute-

villous. Stomata raised on columns (Figures 3-E, G; 4-A,

B). Inflorescences axillary, 1-6 or more, arising directly

from rhizome, sometimes with inflorescence scales at

peduncle base, flowers 8¡V36 in a dichasial cyme, branched

3 to 6 times; staminate flowers 7-32, carpellate flowers

2-6; peduncle well developed, terete, erect or ascending,

(2-)4-14(-19) cm long, 1.5-3 mm thick, brownish, reddish

brown or greenish, pilose or sparsely pilose, sometimes

glabrous. Bracts caducous, reniform, oblong or ovate,

Figure 5. Distribution of Begonia bamaensis (star) in Guangxi

Zhuangzu Autonomous Region, China.

Figure 6. Mitotic chromosome spread of Begonia bamaensis

(2n=30).

Figure 4. SEM micrographs of a stomata complex of Begonia bamaensis. A, Stomata complex in side view; B, Stomata complex in

transverse section and side view, showing the stomata raised on column. Scale bar = 100 £gm. (Photo by Wann-Neng Jane)

LIU

et al. ¡X

Begonia bamaensis

, a new species from China

471

Figure 7. Holotype of Begonia bonii Gagnep. (Bon 2872, P) A, Whole sheet; B, Rhizome and stipules; C, Portion of adaxial leaf

surface. D, Staminate flowers; E, Actinomorphic androecium; F, Materials in the fragment packet.

472

Botanical Studies, Vol. 48, 2007

red hispid-hirsute); capsule 7-12 mm long (vs. 10-20 mm

long), abaxial wing of capsule distinctly curved on one

side (vs. straight or slightly curved). SEM micrographs of

leaves of B. bamaensis (Figures 3-E, G; 4-A, B) revealed

prominently elevated stomata complexes, which is unique

for the genus Begonia. A comparison of the salient

characters of B. bamaensis with three other congeners in

sect. Coelocentrum, one of which, B. bonii, from northern

Vietnam, is shown in Table 1. Begonia bamaensis has

a somatic chromosome number of 2n = 30 (Figure 6),

which agrees with all other members of Begonia sect.

Coelocentrum for which chromosome numbers were

reported (Ku et al., 2004; Peng et al., 2005a, 2005b; Liu

et al., 2005; Fang et al., 2006; Ku et al., 2006; Peng et al.,

2007).

Acknowledgements. We thank Wann-Neng Jane for

guidance and support on Cryo Scanning Electron

Microscopy; Qiner Yang for the Latin diagnosis; curators

of K, KUN and P for the loan of Begonia types; Ming-

Chao Yu for technical assistance; Wei-Bin Xu, Hai-Shan

Gao, Wai-Chao Leong, Yu-Min Shui, Kuo-Fang Chung

and Ming-Chao Yu for accompanying us in the field.

This study was supported in part by grants from Guangxi

Natural Science Foundation (GKJ0448089) to Yan Liu

(IBK) and Research Center for Biodiversity, Academia

Sinica, Taipei to Ching-I Peng (HAST).

LITERATURE CITED

Fang, D., S.M. Ku, Y.G. Wei, D.H. Qin, and C.-I Peng.

2006. Three new taxa of Begonia (s ect. Coelocentrum,

Begoniaceae) from limestone areas in Guangxi, China. Bot.

Stud. 47: 97-110.

Gu, C. Z., C.-I Peng, and N. J. Turland. 2007. Begoniaceae. In Z.

Y. Wu, P. H. Raven, and D. Y. Hong (eds.), Flora of China,

Vol. 13. S cience P res s, Beijing and Missouri Botanical

Garden Press, St. Louis, pp. 153-207.

Ku, S. M., C.-I Peng, and Y. Liu. 2004. Notes on Begonia (sect.

Coelocentrum, Begoniaceae) from Guangxi, China, with

the report of two new s pecies. Bot. Bull. Acad. Sin. 45:

353-367.

Ku, S.M., Y. Liu, and C.-I Peng. 2006. Four new s pecies of

Begonia sect. Coelocentrum (Begoniaceae) from limestone

areas in Guangxi, China. Bot. Stud. 47: 207-222.

Li, H.J., H. Ma, K.Y. Gua n, and C.-I P eng. 2005. Begonia

rubinea (sect. Platycentrum, Begoniaceae), a new species

from Guizhou, China. Bot. Bull. Acad. Sin. 46: 377-383.

Liu, Y., S.M. Ku, and C.-I Peng. 2005. Begonia picturata (sect.

Coelocentrum, Begoniaceae), a new species from limestone

areas in Guangxi, China. Bot. Bull. Acad. Sin. 46: 367-376.

Peng, C.-I, Y.M. Shui, Y. Liu, and S.M. Ku. 2005a. Begonia

fangii (sect. Coelocentrum, Begoniaceae), a new species

from limestone areas in Guangxi, China. Bot. Bull. Acad.

Sin. 46: 83-89.

20-35, golf-club-shaped; filaments subequal, 1.1-1.3 mm

long, partly fused at base; anthers ¡Ó ascending, 2-locular,

slightly compressed, oblong-obovoid, connective apex

slightly emarginate, 0.9-1.3 mm long, 0.6¡V0.7 mm wide,

yellow. Carpellate flowers: pedicel 4-15 mm long,

horizontally spreading to pendent, bracteole absent or

sometimes 1, small; tepals 3, caducous, if persistent not

thickened when fruiting, outer 2 tepals suborbicular or

broadly obovate, margin entire, eciliate, 7-13.5 mm long,

7-14.5 mm wide, white or pinkish, abaxially pilose;

inner tepal oblanceolate, obovate or narrowly so, base

cuneate, apex obtuse, 7-10 mm long, 3-4 mm wide, white,

glabrous; ovary trigonous-ellipsoid, (4.5-)9-11.5 mm long,

(2-)3.5-4.5 mm thick (wings excluded), white or reddish

white, hirsute-pilose or villous-pilose (trichomes 1-2 mm

long, ¡Ócurly, white or reddish), 3-winged; 1-locular with

intruded parietal placentation (axile at base); placentae 3,

each bifurcate; styles 3, nearly free, yellow, ca. 2-3.5 mm

long, apically C-shaped; stigmatic band spiraled. Capsule

nodding, trigonous-ellipsoid, 7-12 mm long, 5-7 mm

thick (wings excluded), apex with persistent styles; wings

unequal or subequal; lateral wings 1-2.5 mm tall; abaxial

wing crescent-shaped or nearly so, 3-5 mm tall, distinctly

curved toward one side. Seeds numerous, brown, ellipsoid

or broadly so, 0.43-0.63 mm long, 0.26-0.34 mm thick,

chalazal end rounded, micropylar end obtuse or slightly

constricted, outer periclinal walls of mature seeds concave;

collar cells elongated, straight, nearly rectangular, 10-14

cells in a ring, occupying 1/4-1/2 of seed length.

Additional specimens examined. CHINA. Guangxi

Zhuangzu Autonomous Region, Bama Yaozu Zizhixian,

Jiazhuan Xiang, Renxiang Cun, at entrance of a cave,

410 alt., 24¢X19¡¦23" N, 107¢X05¡¦32" E, rare, 28 Aug 2005,

Yan Liu L1278 (IBK); same locality as that of the type

collection, 24 May 2002, C.-I Peng 18752 (HAST),

accompanied by Yu-Min Shui and Wai-Chao Leong.

Ecology. On semishady rocky cliff at entrance of

limestone caverns.

Distribution. Western Guangxi, China (Figure 5), rare,

currently known only from two nearby karst caves in

western Guangxi.

Etymology. The specific epithet is derived from

the type locality, Bama Yaozu Zizhixian (Bama Yao

Autonomous County).

Phenology. Flowering from May to December; fruiting

from Jun to March.

Notes. Begonia bamaensis Yan Liu & C.-I Peng is

similar to B. cirrosa L.B. Smith & D.C. Wasshausen,

differing in the leaves adaxially densely setulose or

hispidulous (vs. pilose or pilose-setose) and adorned with

white bands or patches between major veins (vs. without

white maculation); stipules abaxially glabrous or with

few hairs along midrib (vs. pubescent throughout outer

surface); peduncle pilose or sparsely so (vs. villous);

staminate flower with outer tepals 7-14.5 ¡Ñ 7-13.5 mm

(vs. 7-17 ¡Ñ 7-22 mm); ovary whitish or reddish pilose (vs.

LIU

et al. ¡X

Begonia bamaensis

, a new species from China

473

Peng, C.-I, S.M. Ku, and W.C. Leong. 2005b. Begonia liuyanii

(sect. Coelocentrum, Begoniaceae), a new species from

limestone areas in Guangxi, China. Bot. Bull. Acad. Sin.

46: 245-254.

P eng, C.-I, W.C. Leong, S.M. Ku, and Y. Liu. 2006. Begonia

pulvinifera (se ct. Diploclinium, Be goniacea e), a new

species from limestone areas in Guangxi, China. Bot. Stud.

47: 319-327.

Peng, C.-I, T.Y. Hsieh, and N.Q. Ngyuen. 2007. Begonia kui

(sect. Coelocentrum, Begoniaceae), a new s pecies from

Vietnam. Bot. Stud. 48: 127-132.

Shui, Y.M., C.-I P eng, and C.Y. Wu. 2002. Synopsis of the

Chinese species of Begonia (Be go nia c ea e ), wi th a

reappraisal of the sectional delimitation. Bot. Bull. Acad.

Sin. 43: 313-327.