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 mossy forest along rocky tops of remnant karst limestone ridge at 1100-1240 m elev. Terrestrial forb up to 0.5 m hg. Flowers yellow. Rare.
NTH 2981 29 May 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)