Molecular and morphological evidence for a new species of Stachys (Lamiaceae) from Hunan, China.

Stachysyingzuijieensis , a new species from western Hunan, China, is described and illustrated. Molecular phylogenetic analyses based on three nuclear ribosomal DNA loci (ETS, ITS and 5S-NTS) recovered S.yingzuijieensis within the Stachys clade and as a sister group of S.arrecta . The two species can be easily distinguished by the morphology of lamina, corolla and nutlet. A key to all species of Stachydeae from China is also provided.