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 800 m elev. Terrestrial and lithophyte forb on open slope. Flowers white. Very common at elev. 750-1000 m.
NTH 2935 29 May 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)