Sarcostoma is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of epiphytic

Epiphyte

An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...

 orchids with 5 species endemic to Malaysia. The rhizome

Rhizome

In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...

s are short and branched, with short stems bearing 1-3 apical leaves and a single resupinate flower. The sepals are lateral, and the lip trilobed. Sarcostoma is similar to Dendrobium

Dendrobium

Dendrobium is a huge genus of orchids. It was established by Olof Swartz in 1799 and today contains about 1,200 species. The genus occurs in diverse habitats throughout much of south, east and southeast Asia, including the Philippines, Borneo, Australia, New Guinea, Solomon Islands and New Zealand...

and especially Ceratostylis

Ceratostylis

Ceratostylis is a genus of orchids with more than 60 species distributed in India, Southeast Asia, Papua New Guinea , the Philippines, and the Pacific islands.-List of species:...

in having the foot of the column forming a projecting mentum. However it is distinguished from the latter genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 (in which it was formerly included) by the lack of arms on the column and by the presence of 4 rather than 8 pollinia.