Begonia difformis comb. & stat. nov. (Sect. Platycentrum, Begoniaceae), a new species segregated from B. Palmata D. Don

Abstract

Begonia palmata D. Don is one of the most widely distributed and morphologically variable species of Asian Begoniaceae. Examinations of its morphological variation indicate that two of its seven varieties, B. palmata var. difformis and B. palmata var. crassisetulosa, both distributed in the Gaoligong Mountain areas of Yunnan, China are indistinguishable and yet distinct from other varieties. Phylogenetic analyses using ITS DNA sequences further reveals that samples identifiable to these two varieties are also distantly related to samples of typical B. palmata. Based on these observations, we combine and elevate these two varieties to the status of species, Begonia difformis (Irmsch.) W.C. Leong, C.I Peng & K.F Chung, comb. & stat. nov..