Scutellaria cavicola (Lamiaceae), a new cave-dwelling species from Northwest Guangxi, China

Scutellaria cavicola C.Xiong, Z.Y.Wei & L.F.Fu, a new cave-dwelling species discovered in Lingyun County, Guangxi, China, was described and illustrated. The new species morphologically resembles S. tsinyunensis in having ligneous stems, stiffly papery leaves, undulate leaf margins. However, it can be clearly distinguished from S. tsinyunensis in the height of plants, the shape of leaf blades, the length of petiole and racemes, the size of leaves and nutlets. The results of molecular phylogenetic analysis, based on nuclear ribosome internal transcribed spacer (ITS) and external transcribed spacers (ETS) of 43 Scutellaria species, showed that S. cavicola is closely related to S. tsinyunensis. Notably, according to the IUCN Red List Categories and Criteria, the new species is assigned to the Critically Endangered (CR) category.