Primulinaxingyiensis (Gesneriaceae), a new species in the karst landforms of Guizhou Province, China.

Primulinaxingyiensis X.X.Bai & F.Wen, a new species of Gesneriaceae in the karst landforms of Xingyi City, Guizhou Province, China, is described and illustrated. Morphologically, the species is similar to P.davidioides on corolla, while it is distinguished from P.davidioides by characteristics of thinner and smaller leaves, shorter peduncles, fewer flowers, smaller corolla, glabrous staminodes, and ovary shorter than style. Molecular phylogenetic analysis based on the combined dataset of rpl32-trnL, trnL-trnF, atpB-rbcL, and ITS sequences of the new species and 151 other species of Primulina Hance showed that the two populations of P.xingyiensis clustered into a clade, while it was most closely related to P.malingheensis. Following criteria D1 in the IUCN Red List Categories and Criteria, the new species should be assessed as 'vulnerable' (VU).