Taxonomic study of Polystachya Hook. (Orchidaceae) from Asia

Abstract

In Asia, three species of Polystachya (Orchidaceae) are recognized, based on detailed morphological studies. They occur in southern Asia, from Tamil Nadu State in southern India and Yunnan Province in southeastern China to Sumbawa Island in southern Indonesia. As circumscribed here, two Asiatic species are endemic to southern India apart from P. concreta, which is a taxon of pantropical distribution. As part of a detailed nomenclatural review, 21 lectotypes and 1 neotype are designated. For each species treated, a full synonymy, detailed description, illustration, and distribution map are provided. A key for determination of the Asiatic species is included. One species from southeastern India (Kalrayan Hills) is newly described: P. seidenfadeniana. Dendrobium parvum Seidenf. is reduced to a synonym of Polystachya concreta (Jacq.) Garay & H. R. Sweet. © 2010 The Author(s).