N. Vietnam, prov. Lai Chau, distr. Sin Ho, municipality Ta Ngau about 30 km of Lai Chau town to the N (N 22°18′ E 103°15′). Secondary open wet mossy evergreen broadleaved forest with remnants of primary elements on rocky foothills of remnant karst limestone ridge at elev. about 1600 m. Forb wine 6-8 m hg with milky juice in open place. Flowers white with violet tint. Rare.
NTH 2753 25 May 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)