Begonia coptidifolia (Begoniaceae), a new species from China

Begonia coptidifolia H. G. Ye, F. G. Wang, Y. S. Ye & C.-I Peng, a new species from Guangdong province, China, is here described and illustrated. Its chromosome number (2n=22) and karyotype are reported. Begonia coptidifolia belongs to sect. Platycentrum and somewhat resembles B. hemsleyana Hook. f., from which it differs by the aerial stems seen only at anthesis (vs. all year round), palmately trisected leaves with pinnately parted lobules (vs. leaves palmately compound with 7-9 petiolulate leaflets) and petioles grooved on adaxial surface (vs. terete). The new species also resembles Begonia pedatifida H. Lev., which, however, has much stouter rhizomes (2-6 cm vs. 0.3-0.5 cm thick), leaves palmatifid with triangular lobules, and terete petioles. Begonia coptidifolia is rare, known only from a small ravine in Ehuangzhang Nature Reserve, Yangchun, Guangdong Province.