The West Malesian genus Cheilosa Blume has been revised; the variabili
ty of the only species, C. montana Blume, will be described. Cheilosa
montana combines the two former species C. montana and C. malayana (Ho
ok. f.) Airy Shaw. Typical for Cheilosa are the presence of glands in
the teeth of the leaves; thyrsoid, mainly unbranched, ramiflorous to t
erminal inflorescences; absence of petals; the presence of a disc; 9 o
r 10 stamens; 3- (rarely 4)-locular ovaries with one ovule per locule;
thick-walled fruits; an aril around the seed; and endosperm. Fascicle
d hairs are usually present on the lower surface of the leaves, but ar
e caducous. The excluded C. whiteana Croizat is provisionally transfer
red as a new species to Trigonostemon by Airy Shaw.