Aster chuanshanensis (Asteraceae), a New Species from Shanxi and Sichuan, China

Aster chuanshanensis W.P. Li, a new species of Asteraceae from Shanxi and Sichuan, China, is described and illustrated based on morphological, micromorphological, molecular and cytological evidence. It is similar to A. indicus and A. shimadae, but differs from them in rhizome type, leaf size and texture, receptacle shape, floral tube and pappi lengths, and in the ratio of stigmatic line to the style arm appendage. Phylogenetic analysis based on nrDNA (ITS and ETS) sequence data supported A. chuanshanensis as a distinct species belonging to sect. Asteromoea. It is diploid with a karyotype 2n = 2x = 18m, which distinguishes it from the morphologically similar species.