Two new species of Litostigma (Gesneriaceae) from China Vietnam border area based on morphological and molecular data, and modification of stigma character of the genus

Litostigma is a recently described small genus with two species from limestone karsts from southwestern China. During the course of field works on the limestone karsts from China Vietnam border area, two unknown species of Litostigma were collected. Molecular phylogenetic analyses based on nuclear ITS sequences strongly confirm the placements of the two new species in Litostigma. Moreover, these two new species can be distinguished from the known two species with distinct morphological characters, further supporting their recognition as new species. With the support of morphological studies and molecular phylogenetic analyses, Litostigma pingbianense and L. napoense are recognized as two new species. The stigma character of Litostigma is modified in this paper, simple or divided stigmas may occur in this genus.