N. Vietnam, prov. Son La, distr. Moc Chau, municipality Chieng Hac, vicinities of Co Liu village (N 20°51′ E 104°38′). Primary evergreen broadleaved wet forest on very steep slopes and bluffs of remnant karst limestone ridge at 1000-1100 m elev. Terrestrial forb on steep shady slope at 1150 m elev. Flowers black-violet. Common.
NTH 2959 29 May 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)