Botanical Studies (2006) 47: 97-110.
*
Corresponding author: E-mail: bopeng@sinica.edu.tw; Tel:
+886-2-2789-3821; Fax: +886-2-2789-1623.
Three new taxa of
Bego nia
(sect.
Co elo centru m
,
Begoniaceae) from limestone areas in Guangxi, China
Ding FANG
1
, Shin-Ming KU
2, 3
, Yi-Gang WEI
4
, De-Hai QIN
1
, and Ching-I PENG
2,*
1
Guangxi Institute of Traditional Medical and Pharmaceutical Sciences, Guangxi Zhuangzu Autonomous Region,
Nanning 530022, China
2
Herbarium, Research Center for Biodiversity, Academia Sinica, Nangang, Taipei 115, Taiwan
3
Department of Life Sciences, National Cheng-Kung University, Tainan 701, Taiwan
4
Guangxi Institute of Botany, Guangxi Zhuangzu Autonomous Region and Academia Sinica, Guilin 541006, China
(Received July 18, 2005; Accepted December 3, 2005)
ABSTRACT.
Begonia ningmingensis, B. ningmingensis var. bella and B. retinervia, three new taxa of B.
sect. Coelocentrum from the karst area in Guangxi Zhuangzu Autonomous Region, China, are described and
illustrated. Notably, their leaves are adorned with white or pale maculation along all major veins. Begonia
ningmingensis var. ningmingensis resembles B. morsei Irmsch., differing by having larger leaves with white
maculation on the major veins and having larger staminate flowers. The maculation pattern in the leaves of
B. morsei is sharply distinct: they are adorned with a broad, white ring between the center of the leaf and
the margin. Begonia ningmingensis var. bella differs from the typical variety mainly by the suborbicular or
reniform leaves with a rounded or obtuse apex (vs. broadly ovate or suborbicular with an acuminate, shortly
acuminate or acute apex). Begonia retinervia is distinct chiefly by having thickly chartaceous leaves, the
broadly trigonous-ovoid or obovoid ovary and fruit covered with crisp-villous hairs, and the ventral surface
markedly convex, and in the much protruded abaxial wing.
Keywords: Begonia morsei; Begonia ningmingensis; Begonia ningmingensis var. bella; Begonia retinervia;
Begoniaceae; Begonia sect. Coelocentrum; China; Chromosome number; Guangxi; Limestone flora; New
species; New variety.
INTRODUCTION
Begonia sect. Coelocentrum comprises about 18 species
that are distributed mainly in southern China, but also in
northern Vietnam (Shui et al, 2002). During the botanical
inventories undertaken in recent years, many new species
were discovered in China: Ku et al. (2004: B. curvicarpa
and B. luochengensis); Liu et al. (2005: B. picturata); Peng
et al. (2005a: B. fangii; 2005b: B. liuyanii), and Nguyen
(2004) published B. phuthoensis from Vietnam. More
recently, Shui and Chen (2005) added 11 new species and
three new varieties for B. sect. Coelocentrum in China and
proposed a new name, B. variegata for B. masoniana var.
maculata S. K. Chen et al. from Vietnam. Begonia sect.
Coelocentrum is therefore much more speciose than was
previously believed. In this study we report two additional
new species and an additional new variety, all with showy
leaves, from the limestone areas in Guangxi, China.
New taxa
1.
Begonia ningmingensis D. Fang, Y. G. Wei & C.-I
Peng, sp. nov. ¡XTYPE: CHINA. Guangxi Zhuangzu
Autonomous Region, Ningming Xian, Tingliang
Xiang, Longrui Nature Protected Area, elev. ca. 140
m, broad-leaved forest, on limestone rock face in
creek, shaded, wet, occasional, living collection, 2
Sep 2002, type specimens (in flower and fruit) pressed
from plants cultivated in experimental greenhouse
at Academia Sinica, 18 Oct 2004, Wai-Chao Leong,
Yan Liu & Shin-Ming Ku 3410-A (holotype: HAST;
isotypes: A, GXMI, IBK, MO, PE). ¹ç©ú¬î®ü´Å
Figures 1, 2
Begonia morsei auct. non Irmsch.: Ku, T. C., Fl. Reipubl.
Popularis Sin. 52(1): 139, pl. 30: 3, 4. 1999, excl. typ.
Begoniae morsei similis, sed a qua differt praecipue
foliis majoribus, decoratis cum macula alba secundum
venas majores, et floribus staminatis majoribus.
Herbs monoecious; epipetric; perennial; rhizomatous.
Rhizome 2-10 cm or more long, (2.5-)5-10(-16) mm
thick, internodes (3-)5-10(-17) mm long, brown, reddish
brown or greenish brown, villous near petiole bases and
TAXONOMY