Coelogyne is a large genus of Asiatic orchids widely distributed from India and Sri Lanka across southern Asia and the Malaya Archipelago to the Philippines, New Guinea and the south-west Pacific Islands. The genus comprises some 190 species, two subspecies and 12 varieties. Keys are provided to the sections, species and infraspecific taxa. There is a comprehensive account for each species that includes a full description, distribution, habitat, altitudinal range, flowering time and taxonomic notes. Most of the species are illustrated by one or more colour photographs; and a black-and-white line drawing of the lip, a critical feature in the genus, is provided for almost every species.