Oreocharis xieyongii, an unusual new species of Gesneriaceae from western Hunan, China

A new species, Oreocharis xieyongii T. Deng, D.G. Zhang & H. Sun, from Hunan Province, central China, is described. The combination of purple zygomorphic corolla with longer adaxial lobes and exserted stamens defines the species and discriminates it from all other current Oreocharis species. Morphological traits of the new species were compared to those of two similar species, Oreocharis xiangguiensis and Oreocharis rubrostriata. Phylogenetic analysis indicates that the new species is nested within the Oreocharis. Although only half of Oreocharis species were included in our study, evolutionary character analysis indicates that the ancestral states of the genus are likely the purple corolla, longer abaxial lip and inserted stamens. The longer adaxial lip is perhaps an apomorphy and only present in O. xieyongii and O. rubrostriata. Both morphological and molecular evidence suggest that O. xieyongii is a taxon new to science.