Isotrema cangyuanense, a new species of Aristolochiaceae from Yunnan, China

Isotrema cangyuanense, a new species from Cangyuan, Yunnan, China, is described and illustrated. This species is morphologically similar to I. kunmingense in the shape of leaf blade and calyx, but clearly differs in its epidermal hair of leaf blade, the colour of calyx tube and throat, the surface texture of calyx limb. Photographs and a comparison table of related species are provided.