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 evergreen closed wet forest on steep slopes of remnant limestone ridge at about 650 m alt. Herb vine up to 4-5 m hg. Common in open places.
CBL 1020 09 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)