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. Open primary coniferous forest (with Pseudotsuga brevifolia) along tops of remnant limestone ridge at 850-900 m alt. Woody vine up to 6-8 m lg. Very common on open slopes at 600-1000 m alt.
CBL 1067 10 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)