N. Vietnam, prov. Cao Bang, distr. Thach An, about 28 km to SE from Cao Bang town (N 22°29′ E 106°28). Primary evergreen broadleaved closed wet forest along deep shadow canyon of remnant limestone ridge at 300-400 m alt. Woody vine up to 8 m lg in open place. Not common.
CBL 968 06 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)