N. Vietnam, prov. Cao Bang, distr. Tra Linh, municipality Quang Vinh (N 22°51′ E 106°14′), about 21 km from Cao Bang town to the N. Secondary closed broadleaved wet forest on steep slopes of remnant limestone ridge at 700-750 m alt. Woody vine or climbing shrub up to 4-5 m hg in open place. Flowers dull yellowish. Not common.
CBL 1074 10 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)