Begonia liuyanii (sect. Coelocentrum, Begoniaceae), a new species from limestone areas in Guangxi, China

Begonia liuyanii, a new species of sect. Coelocentrum from limestone areas in southwestern Guangxi Zhuang Autonomous Region, China, is described and illustrated. A somatic chromosome number of 2n = 30 was determined. Begonia liuyanii is similar to B. filiformis in having small flowers and glandular-hispid inflorescences but is distinguishable by its larger leaves (16-38 x 12-32 cm vs. 9-22 x 9-14 cm), sparsely setose (vs. tomentose) upper surface of the leaves, maculation absent (vs. with white maculation in intercostal area on adaxial leaf surface), and usually thyrsoid (vs. cymose) inflorescence.