Botanical Studies (2008) 49: 167-175.
Corresponding author: E-mail:; Tel:
Begonia pengii (sect. Coelocentrum, Begoniaceae), a
new species from limestone areas in Guangxi, China
Shin-Ming KU
, Yoshiko KONO
, and Yan LIU
Herbarium (HAST), Research Center for Biodiversity, Academia Sinica, Nangang, Taipei 115, Taiwan
Guangxi Institute of Botany, Guangxi Zhuangzu Autonomous Region and the Chinese Academy of Sciences, Guilin
541006, China
(Received September 5, 2007; Accepted March 7, 2008)
Begonia pengii, a new species from Guangxi Zhuangzu Autonomous Region, China, is here
described and illustrated. Its somatic chromosome number (2n = 30) and karyotype are reported. Begonia
pengii belongs to sect. Coelocentrum and somewhat resembles B. variifolia Y. M. Shui & W. H. Chen, from
which it differs by its much larger size, leaves (11-)15-27 × (6-)8-15 cm, narrowly ovate, peduncle 17-37 cm;
anther sacs red margined; and capsules 1.8-2.5 cm long. Like most members of sect. Coelocentrum, B. pengii
is an attractive species and is rare, known only from one steep limestone hill in western Guangxi.
Keywords: Begonia luochengensis; Begonia pengii; Begonia picturata; Begonia sect. Coelocentrum; Begonia
variifolia; Begoniaceae; China; Chromosome number; Guangxi; Karyotype; Limestone flora; New species;
Rare species.
The spectacular karst limestone landform in Guangxi,
China is home to many endemic and rare species. As
a result of our continued fieldwork in Guangxi and
research on Begonia, an attractive new species of sect.
Coelocentrum was discovered, which is described below.
Cryo scanning electron microscopy
Fresh leaves of Begonia pengii were dissected and
attached to a stub. The samples were frozen with liquid
nitrogen slush, then transferred to a sample preparation
chamber at -160°C. After 5 min, when the temperature
rose to -130°C, the samples were fractured. The samples
were etched for 10 min at -85°C. After coating at -130
°C, the samples were transferred to the SEM chamber
and observed at -160°C with a cryo scanning electron
microscope (FEI Quanta 200 SEM/Quorum Cryo System
PP2000TR FEI).
Chromosome preparations
Root tips of Begonia pengii were pretreated with 2
mM 8-hydroxyquinoline solution at 15-18°C for about 8
h and fixed in ethanol-acetic acid (3:1) at about 4°C for
more than 24 h. Chromosome preparations were made
by the enzyme squash method in an enzyme mixture of
4% Cellulase (Onozuka R-10, Yakult) and 2% Pectolyase
Y-23 (Kyowa Chemical Products) at about 37°C for 1 h.
The preparations were stained with 2% Giemsa solution
(Merck). Classification of the chromosome complements
based on centromere position at mitotic metaphase follows
Levan et al. (1964). The voucher specimen has been
deposited in HAST.
Begonia pengii S. M. Ku & Yan Liu, sp. nov. —TYPE:
CHINA. Guangxi Zhuangzu Autonomous Region,
Bama Xian, Xishan. Sheltered, vertical limestone rock
face, ca. 500 m alt. 18 May 2007, Ching-I Peng, Yan
Liu, Kuo-Fang Chung, Ming-Chao Yu & Hai-Shan
Gao 21070 (holotype: HAST; isotype: IBK).
彭氏秋海棠 Figures 1, 2, 3A
Begoniae variifoliae Y. M. Shui & W. H. Chen affinis,
sed foliis anguste ovatis, antherarum saccis rubro-
marginatis, habitu multo majore [foliis (11-)17-27
× (6-)8.5-15 cm, pedunculis 17-30 cm longis, capsulis
1.8-2.5 cm longis] differt.
Herbs, monoecious, epipetric, perennial, rhizomatous.
Rhizome 6-15 cm or longer, (5-)9-12(-18) mm thick,
internodes (5-)7-10(-12) mm long, brown or reddish
brown, villous near base of petiole and leaf scars. Stipules
eventually caducous, narrowly triangular-ovate, 12-15 mm
long, 5-8 mm wide, reddish hyaline, herbaceous, weakly
or not keeled, glabrous, margin eciliate, apex aristate,
Botanical Studies, Vol. 49, 2008
Figure 1. Begonia pengii S. M. Ku & Yan Liu. A, Habit; B, Portion of leaf, adaxial surface, showing margin and indumentum, B’,
abaxial surface, B’’, cross section; C, Stipule; D, Bract; E, Staminate flower, face view, E’, side view; F. Androecium; G, G’, G’’,
Stamens; H, Carpellate flower, face view, H’, side view; I, I’, II’’, Style and stigma; J, Dry capsule; K, Capsule, cross section; L, Seeds.
All but A, J from Peng et al. 20724 (HAST); A, J from Peng et al. 21070 (HAST).
KU et al. —
Begonia pengii
, a new species from China
Figure 2. Begonia pengii S. M. Ku & Yan Liu. A, Habit; B, Rhizome; C, Leaf adaxial surface; D, Leaf abaxial surface; E, Stipule;
F, Bract; G, Staminate flower, face view; H, Androecium, showing red-margined anther sacs; I, Carpellate flower, face view; J, Young
capsule; K, Dry capsule; L. Middle cross section of a young fruit. All but C-F, K from Peng et al. 21070 (HAST); C-F, K from Peng et
al. 20724 (HAST).
Botanical Studies, Vol. 49, 2008
Figure 3. Holotype specimens. A, Begonia pengii, C.-I Peng et al. 21070 (HAST); B, Begonia variifolia, Y. M. Shui & W. H. Chen
B2004-202 (KUN).
arista 3-5 mm long, hair-like. Leaves 2-8, alternate, simple,
asymmetric, unlobed, narrowly ovate, base peltate (rarely
subpeltate), margin crenate-denticulate and ciliate, apex
acuminate to caudate, (11-)17-27 cm long (basal lobes
included), (6-)8.5-15 cm wide, surface usually adorned
with a wide whitish or pale silvery band (to 2 cm across)
along midrib, pale green or whitish along major veins and
major lateral veins, dark brownish to purplish red between
major veins and major lateral veins, texture papery, surface
rugulose, adaxially densely pilose (trichomes 0.7-1.2(-2)
mm long, whitish-hyaline or reddish), abaxially villose-
pilose, particularly pronounced on veins; venation
basally 6-7-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, forming
a divergence angle of 75-100° to major veins, minor
veins reticulate, all veins on abaxial surface prominently
raised; petiole terete, (10-)15-26 cm long, 3-6.5 mm thick,
brownish or brownish red, hirsute-villous. Inflorescences
axillary, dichasial cymes 1-3 or more, arising directly
from rhizome, branched 2 to 3 times. Flowers 4-12 per
inflorescence; staminate flowers 3-9, carpellate flowers
1-3; peduncle well developed, terete, erect or ascending,
17-37 cm long, 1.5-3 mm thick, brownish or reddish
brown, densely pilose or hispid-villous. Bracts caducous,
oblong, ovate or broadly ovate, margin denticulate and
ciliate, apex obtuse or acute, 4-15 mm long, 3-7 mm
wide. Staminate flowers: pedicel 1-2 cm long, pilose to
hispid; tepals 4, outer 2 broadly ovate or suborbicular,
base rounded or slightly cordate, margin usually ciliate,
apex rounded, 17-21 mm long, 15-20 mm wide, pinkish or
white, abaxially densely pilose (trichomes whitish); inner
2 tepals obovate or elliptic, base cuneate, margin entire,
eciliate, apex obtuse or rounded, 13-17 mm long, 7-10.5
mm wide, white, glabrous; androecium zygomorphic,
subglobose, stamens 30-75, golf-club-shaped; filaments
subequal, 1.5-1.7 mm long, partly fused at base; anthers
± ascending, 2-locular, slightly compressed, obovoid or
oblong-obovoid, connective apex slightly emarginate,
1-1.2 mm long, 0.7-0.8 mm wide, yellow with red margins
along anther sacs. Carpellate flowers: pedicel 15-20 mm
long, horizontally spreading to pendent, bracteole absent;
tepals 3, caducous, outer 2 tepals suborbicular or oblate-
ovate, margin ciliate at lower part or sometimes eciliate,
15-18 mm long, 18-20 mm wide, pinkish or white,
abaxially densely pilose; inner tepal elliptic or broadly
lanceolate, base cuneate, apex obtuse, 9-10 mm long, 6-7
mm wide, white or pinkish, glabrous; ovary trigonous-
ellipsoid, ca. 8 mm long, 5-6 mm thick (wings excluded),
KU et al. —
Begonia pengii
, a new species from China
pilose or villous-pilose, 3-winged; 1-locular with intruded
parietal placentation (axile at base); placentae 3, each
2-branched (T-shaped); styles 3, nearly free, yellow, ca.
4 mm long, apically C-shaped; stigmatic band spiraled.
Capsule nodding, trigonous-ellipsoid, somewhat curved,
18-25 mm long, 6-13 mm thick (wings excluded), apex
with persistent styles; wings unequal; lateral wings 2-3
mm tall; abaxial wing crescent-shaped or nearly so, 7-11
mm tall. Seeds numerous, brown, ellipsoid or narrowly
so, 0.56-0.68 mm long, 0.29-0.32 mm thick, chalazal end
rounded, micropylar end obtuse or slightly constricted,
outer periclinal walls of mature seeds concave; collar
cells elongated, straight, nearly rectangular, 11-14 cells
in a ring, occupying 1/4-1/2 of seed length. Somatic
chromosome number, 2n = 30 (Figure 4).
Additional specimens examined. CHINA. Guangxi
Zhuangzu Autonomous Region, Bama Xian, Xishan,
Limestone rock face, ca. 500 m alt. (same loc. as the type
collection), 17 Dec 2005, Ching-I Peng, Shin-Ming Ku,
Yan Liu, and Tsung-Han Tsai 20724 (HAST).
Habitat and Ecology. Begonia pengii was found in
small populations on vertical, usually sheltered, rock faces
in evergreen forests on jagged limestone hills.
Distribution. Endemic to western Guangxi, China
(Figure 5); rare.
Etymology. We dedicate this new, handsome species of
Begonia to Dr. Ching-I Peng, mentor of the first author.
The specific epithet recognizes his emphatic interest and
substantial contribution to the study of Asiatic Begonia.
Heretofore, Dr. Peng and his associates have described 27
new species of Begonia (Peng et al., 1988; Peng and Chen,
1990; Peng and Sue, 2000; Ye et al., 2004; Ku et al., 2004;
Peng et al., 2005a, b, c; Liu et al., 2005; Li et al., 2005;
Peng et al., 2006a, b; Fang et al., 2006; Ku et al., 2006;
Peng et al., 2007; Liu et al., 2007; Peng et al., 2008), many
of which are of great horticultural potential.
Leaf anatomy and vestiture. Adaxial surface with
multiseriate trichomes 0.7-1.2 mm long (Figure 6A,
B); upper epidermal cells conoidal; epidermis single-
layered on both surfaces, hypoderm absent (Figure 6C).
Abaxial surface with intermixed multiseriate trichomes
and unicellular (globose) or bicellular (upper cell globose)
microtrichomes near the veins (Figure 6D, E), a unique
character shared only by two other species in sect.
Coelocentrum: B. asteropyrifolia Y. M. Sh ui & W. H.
Chen and B. variifolia Y. M. Shui & W. H. Chen (Ching-I
Peng, pers. comm.). Stomatal complex single, helicocytic,
subsidiary cells (5-)6, moderately elevated (Figure 6F).
Phenology. Flowering from Mar to June; fruiting from
June to Dec.
Figure 4. Karyomorphology of Begonia pengii. A, Somatic chromosomes at metaphase, 2n = 30; B, Karyotype: chromosomes pairs
arranged by decreasing order of length (from Peng et al. 20724).
Figure 5. Distribution of Begonia pengii (★), B. variifolia
(●), B. luochengensis (■), and B. picturata (▲) in Guangxi
Zhuangzu Autonomous Region, China.
Botanical Studies, Vol. 49, 2008
Figure 6. Leaf SEM microphotographs of Begonia pengii: A, B, Trichomes on upper epidermis; C, Lamina, cross section; D, Lower
epidermis, showing two kinds of trichomes; E, Unicellular and bicellular microtrichomes (lower epidermis); F, Stomatal complex
(lower epidermis).
KU et al. —
Begonia pengii
, a new species from China
Table 1. Comparison of Begonia pengii, B. variifolia, B. luochengensis and B. picturata.
B. pengii
(Figures 1, 2, 3A)
B. variifolia (Figure 3B)
B. luochengensis
(Ku et al., 2004:
Figures 4, 5)
B. picturata (Liu et al.,
2005: Figures 1, 2)
Rhizome diam. (mm) (5-)9-12(-18)
Abaxially villous
Eciliate or remotely
Size (mm)
12-15 × 5-8
5-6 × 3-5
7-10 × 7-9
5.5-23 × 6-10
Narrowly triangular-
Triangular-ovate to
Ovate-triangular to
Size (cm)
(11-)15-23(-27) ×
5-10 × 3.5-7.2
5-20 × 7-12
(7-)10-15(-20) ×
Peltate (rarely
Peltate, subpeltate to
With a prominent white
band along midrib; pale
green or white along
major veins and lateral
veins; usually dark
brownish to purplish
red between major
With or without a
narrow white band
along midrib, pale
green along major
veins and major
lateral veins; green
or brownish between
major veins
With a prominent
white band along
midrib, pale green
along major veins
and lateral veins,
dark brownish
to purplish red
between major
With a wide white,
greenish-white, or
pale green ring in
the middle or with
digitate dark brown
bands along main
veins and at leaf
margin, pale green,
yellowish green to
whitish elsewhere
Tertiary venation Reticulate and percurrent Reticulate and
Ramified or loosely
reticulate, not
Reticulate and
Densely pilose or hispid-
Pilose to hirsute-villous Glabrous
Length (cm)
Outer staminate tepals Densely pilose, usually
Densely pilose, usually
Glabrous, eciliate Hirsute, eciliate
Anther sac
Yellow with red margins Yellow throughout Yellow throughout Yellow with red
Size (mm)
8-14 × 4-6
11-17 × 6-7
10-15 × 6-8
Pilose or villous-pilose Pilose or villous-pilose Glabrous
Villous-setose or
Chromosome cytology. Somatic chromosomes at
mitotic metaphase of Begonia pengii were determined
t o be 2 n = 30 (Figure 4). The chromosomes showed a
bimodal variation in length. Of the 30 chromosomes,
two were about 2 μm long (Figure 4-B: nos. 1 and 2); the
remaining 28 were shorter, ranging from about 0.9-1.4
μm in length. While the position of the centromere of
some shorter chromosomes was unclear, the two longest
chromosomes had centromere in the median position.
Satellite chromosomes were not observed.
Botanical Studies, Vol. 49, 2008
The chromosome number of all 14 taxa of Begonia in
sect. Coelocentrum reported earlier are uniformly 2n = 30
(Fang et al., 2006; Ku et al., 2004, 2006; Liu et al., 2005,
2007; Peng et al., 2005a, 2005b, 2007, 2008). Two taxa,
B. ningmingensis var. bella and B. kui, clearly showed
bimodal variation in chromosome length (Fang et al.,
2006; Peng et al., 2007).
Morphological notes. Begonia pengii is similar to B.
variifolia (Shui and Chen, 2005), differing in the much
larger size, leaves (11-)15-27 × (6-)8-15 cm (vs. 5-10
× 3.5-7.2 cm), narrowly ovate (vs. broadly ovate to
ovate), peduncle 17-30 cm (vs. 7.5-21 cm); margin of
the anther sacs red; and capsules 1.8-2.5 cm (vs. 0.8-1.4
cm). Begonia sect. Coelocentrum comprises more than 40
species. Red-margined anther sacs are known only in B.
pengii and B. picturata. Detailed comparison of B. pengii
with related species is presented in Table 1.
Acknowledgments. We thank Qiner Yang (PE) for the
Latin diagnosis; David E. Boufford (A/GH) and Thomas
G. Lammers (OSH) for improving the manuscript; De-
Zhu Li (KUN) for facilitating the loan of Begonia types;
Hai-Shan Gao (IBK), Kuo-Fang Chung, Tsung-Han Tsai
(HAST) for field assistance; and Ming-Chao Yu (HAST)
for the handsome line drawings and field assistance.
This study was supported in part by a Personnel Training
Plan of West Light Foundation of the Chinese Academy
of Sciences (2007) to Yan Liu (IBK) and grants from th e
National Science Council and Academia Sinica, Taiwan
to Ching-I Peng (HAST).
Fang, D., S.M. Ku, Y.G. Wei, D.H. Qin, and C.-I Peng.
2006. Three new taxa of Begonia (sect. Coelocentrum,
Begoniaceae) from limestone areas in Guangxi, China. Bot.
Stud. 47: 97-110.
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 species. Bot. Bull. Acad. Sin. 45:
Ku, S.M., Y. Liu, and C.-I P eng. 2006. Four new species of
Begonia sect. Coelocentrum (Begoniaceae) from limestone
areas in Guangxi, China. Bot. Stud. 47: 207-222.
L i, H.J., H. Ma, K.Y. Guan, and C.-I Peng. 2005. B egonia
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.
Liu, Y., S.M. Ku, and C.-I Peng. 2007. Begonia bamaensis (sect.
Coelocentrum, Begoniaceae), a new species from limestone
areas in Guangxi, China. Bot. Stud. 48: 465-473.
Levan, A., K. Fredga, and A.A. Sandberg. 1964. Nomenclature
for centromeric position on chromosom e. Hereditas 52:
P eng, C.-I, Y.K. Chen, and H.F. Yen. 1988. Begonia ravenii
(Begoniaceae), a new species from Taiwan. Bot. Bull. Acad.
Sin. 29: 217-222.
P eng, C.-I and Y.K. Chen. 1990. Begonia aus trotaiwanensis
(Begoniaceae), a new s pecies from southern Taiwan. J.
Arnold Arb. 71: 567-574.
P eng, C.-I a nd C.Y. Sue. 2000. Begonia ×taipeiensis P eng
(Begoniaceae), a new hybrid in Taiwan. Bot. Bull. Acad.
Sin. 41: 151-158.
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.
Peng, C.-I, S.M. Ku, and W.C. Leong. 2005b. Begonia liuyanii
(s ect. Coelocentrum, Begoniaceae), a new species from
limestone areas in Guangxi, China. Bot. Bull. Acad. Sin.
46: 245-254.
Peng, C.-I, Y.K. Chen, and W.C. Leong. 2005c. Five new species
of Begonia (Begoniaceae) from Taiwan. Bot. Bull. Acad.
Sin. 46: 255-272.
P eng, C.-I, W.C. Leong, and Y.M. Shui. 2006a. Novelties in
Begonia sect. Platycentrum for China: B. crocea, sp. nov.
and B. xanthina Hook., a new distributional record. Bot.
Stud. 47: 89-96.
Peng, C.-I, W.C. Leong, S.M. Ku, and Y. Liu. 2006b. Begonia
pulvinifera (sec t. Diploclinium, Begoni acea e), a new
species from limestone areas in Guangxi, China. Bot. Stud.
47: 319-327.
Peng, C.-I, T.Y. Hsieh, and Q.H. Ngyuen. 2007. Begonia kui
(sect. Coelocentrum, Begoniaceae), a new species from
Vietnam. Bot. Stud. 48: 127-132.
Peng, C.-I, Y. Liu, and S.M. Ku. 2008. Begonia aurantiflora
(sect. Coelocentrum, Begoniaceae), a new species from
limestone areas in Guangxi, China. Bot. Stud. 49: 83-92.
Shui, Y.M. and W.H. Chen. 2005. New data of sect.
Coelocentrum (Begonia) in Begoniaceae. Acta Bot. Yunnan.
27(4): 355-374.
Ye, H.G., F.G. Wang, Y.S. Ye, and C.-I Peng. 2004. Begonia
coptidifolia (Begoniaceae), a new species from China. Bot.
Bull. Acad. Sin. 45: 259-266.
KU et al. —
Begonia pengii
, a new species from China
 劉 演
中央研究院生物多樣性研究中心 植物標本館(HAST)
廣西壯族自治區 中國科學院廣西植物研究所
本文報導中國廣西壯族自治區的秋海棠屬側½組 (Begonia sect. Coelocentrum) 一新種:彭氏秋海棠
(Begonia pengii)。本研究除提供½繪圖與彩色照片以資辨識外,並報導其染色體數 (2n = 30) 與核型。彭
秋海棠與多變秋海棠 (B. variifolia) 略似,
但植株明顯碩大:葉片大小為 (11-)15-27 × (6-)8-15 cm (後者
5-10 × 3.5-7.2 cm),總花梗長 17-37 cm (後者7.5-21 cm),蒴果長 1.8-2.5 cm (後者 0.8-1.4 cm);此外,葉