Petrocodon chishuiensis (Gesneriaceae), a new species endemic to Guizhou, China

A new species, Petrocodon chishuiensis Z.B. Xin, F. Wen & S.B. Zhou, from NW Guizhou, China, is described and illustrated here. It shares a rare characteristic with P. hunanensis X.L. Yu & Ming Li, P. tongziensis R.B. Zhang & F. Wen and P. longitubus Cong R. Li & Yang Luo: all have four fertile stamens, a character state distinguishing this clade from the rest of Petrocodon. P. chishuiensis closely resembles P. hunanensis and P. tongziensis, but differs in vegetative and generative characters. We found only one population with no more than 60 mature individuals at the type locality. This species is provisionally assessed as Critically Endangered (CR B2ab(iii)) using IUCN criteria.