Cheirostylis, commonly known as fleshy jewel orchids or velvet orchids, is a genus of about 50–60 species of flowering plants in the orchid family Orchidaceae (order Asparagales). Plants are small terrestrial or occasionally epiphytic herbs with a distinctive creeping, caterpillar-like, fleshy rhizome anchored to the ground by fine white root hairs. The leaves are thinly textured, ovate to cordate, arranged in a loose rosette, and typically withered by flowering time. Inflorescences are erect, terminal racemes bearing one to many small, white, hairy, resupinate flowers. The sepals are membranous and fused for half to almost their entire length, forming a tube. The lip is three-partite with a saccate hypochile containing fleshy papillose calli and a spreading, two-lobed epichile. The column is short with two elongate stelidia (arm-like appendages) and a deeply bifid rostellum. The genus was first described by Carl Ludwig Blume in 1825, with C. montana as the type species. Cheirostylis species are found in tropical Africa, southern and eastern Asia, Southeast Asia, Malesia, New Guinea, Australia, and some Pacific islands, with the greatest diversity in China (17 species, eight endemic). They are prized as "jewel orchids" for their attractive foliage patterns.
Distribution
Cheirostylis species occur from tropical Africa through tropical and subtropical Asia (including Japan), Southeast Asia, Malesia, New Guinea, to Australia and some Pacific islands. China hosts the greatest diversity with 17 species, eight of which are endemic. Two species are endemic to Australia.
Taxonomy Notes
The genus Cheirostylis was first described by Carl Ludwig Blume in 1825 in Bijdragen tot de flora van Nederlandsch Indië. Hayata proposed segregating species with an entire lip into the genus Arisanorchis, but these are now considered peloric forms of Cheirostylis and the genus is retained. Synonyms include Arisanorchis Hayata, Gymnochilus Blume, and Mariarisqueta Guinea. A comprehensive monographic revision is needed, as overlapping species concepts remain problematic — particularly for endemic species of Taiwan and Hong Kong, which remain poorly known.
