Petrocodon albinervius, a new species of Gesneriaceae from limestone areas in southwestern Guangxi, China

Petrocodon albinervius D.X. Nong ＆ Y.S. Huang (Gesneriaceae) is described and illustrated as a species new to science occurring in the limestone area of southwestern Guangxi, China. It shows overall most similarity with P. ionophyllus F. Wen, S. Li ＆ B. Pan, P. integrifolius (D. Fang ＆ L. Zeng) A. Weber ＆ Mich. Möller and P. ainsliifolius W.H. Chen ＆ Y.M. Shui in leaf shape, but differs in several characters such as the leaf blade indumentum, leaf veins coloration, the size and shape of bracts, the number of cymes per plant and flowers per cyme, and the shape of the stigma. Besides a diagnosis and detailed description, we also provide ecological information, photographic images, a table and taxonomic notes to distinguish several other morphologically similar Petrocodon species and proposed conservation status for this species.