What is "sarcostoma"

Sarcostoma is a genus of epiphytic orchids with 5 species endemic to Malaysia. The rhizomes 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 and especially Ceratostylis in having the foot of the column forming a projecting mentum. However it is distinguished from the latter genus (in which it was formerly included) by the lack of arms on the column and by the presence of 4 rather than 8 pollinia.