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 900-1000 m elev. Terrestrial forb up to 1.5 m hg in open place. Flowers light greenish-white. Stem at lower portion dirty purple. Common.
NTH 2952 29 May 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)