Content area
Full Text
(ProQuest: ... denotes non-US-ASCII text omitted.)
Introduction
In Thailand the species-rich genus Begonia L. (Begoniaceae) was previously represented by 45 species (Craib, 1931). Later, Hughes (2008) reported 49 species, with 26 of these being endemic to the country. Following extensive field surveys carried out in Thailand from June 2007 to December 2009, together with study of specimens from various herbaria (AAU, ABD, BK, BKF, BM, C, E, K, L, PSU, SING), 54 species of Begonia are now recorded from Thailand. Forty-five of these species have been observed and collected in the wild by one or more of the authors (Phutthai et al., 2009).
Recent collections from Phangnga province in Peninsular Thailand revealed an undescribed species, belonging to Begonia sect. Parvibegonia. This section is distributed from the Himalayas to Indo-China, Malaysia and Indonesia (Doorenbos et al., 1998; Hughes, 2008), and its members are generally small plants distinguished by the combination of a tuberous habit, female flowers with two stigmas, two-locular fruits with one enlarged wing, and bifid placentae. The new species, Begonia bella, was collected at one locality at Namtok Ra Man Waterfall, and is probably endemic to that area. It is a lithophytic herb, growing on wet granitic rocks by streams in deep shade in dry evergreen forest.
Species Description
Begonia bella Phutthai, sp. nov. Sect. Parvibegonia. Figs 1-3.
Fig. 1.
Begonia bella Phutthai. A, habit; B, staminate flower; C (front view)-D (side view), pistillate flower; E, trichome; F, young fruit with persistent stigma; G, capsule; H, ovary, middle cross-section; I, stamen.
Fig. 2.
Begonia bella Phutthai. A, habit and habitat; B, tuber with fibrous roots; C, leaf adaxial surface; D, trichomes on adaxial leaf surface; E, inflorescence; F, staminate flower; G, pistillate flower; H, young fruit with persistent stigma.
Fig. 3.
The distribution of Begonia bella Phutthai ([black triangle up]) in Peninsular Thailand.
Vegetatively this species is most similar to Begonia integrifolia Dalzell, but differs in having dentate (not entire) leaf...