N. Vietnam, prov. Cao Bang, distr. Thach An, about 25 km to SSE from Cao Bang town (N 22°27′ E 106°22). Primary evergreen closed semideciduous forest on tops of remnant limestone ridge at 500 m alt. Woody vine up to 8-10 m lg in open cliffs. Flowers green. Not common.
CBL 920 05 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)