N. Vietnam, prov. Cao Bang, distr. Tra Linh, municipality Co Muoi, vicinities of Lung Dat village (N 22°51′ E 106°14′), about 22 km from Cao Bang town to the N. Primary evergreen broadleaved closed forest on steep slopes of remnant limestone ridge at 650-700 m alt. Woody vine up to 6-8 m in open place. Flowers yellowish-green (male flowers with 3 stamens). Not common.
CBL 1133 12 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)