Abstract
Plants belonging to the genus Petrocosmea are rare and small herbs difficult to find in the wild. In the present study, a new species, Petrocosmeaduyunensis, from Guizhou, China, is described. The species is most similar to P.leiandra and differs from it by a distinctly recurved abaxial corolla lip, free anthers and included pistil. Detailed morphological comparisons are given. One population with about 100 mature individuals was found at the type locality. This new taxon was assessed as "Data Deficient" (DD) according to the IUCN standards.