Gastorchilus pseudodresslerii (Orchidaceae; Vandeae), a new species from China: evidence from morphological and DNA analysis

Gastrochilus pseudodresslerii (Aeridinae), a new species from Maguan County, Yunnan Province, China, is described and illustrated. Morphological comparisons indicated that this new species is similar to G. dresslerii, but differs by its longer and broadly lanceolate to oblong leaves, larger and elliptic dorsal sepal, longer and elliptic petals, subcupular hypochile, and narrowed toward apex of column. Phylogenetic analysis based on nuclear ribosomal ITS and four plastid sequences (atpI, matK, psbA and trnL-F) indicated that G. pseudodresslerii is also closely related to G. formosanus and G. raraensis, but can be easily distinguished from these two species based on its leaves, epichile and hypochile.