N. Vietnam, prov. Cao Bang, distr. Bao Lac, municipality Ca Thanh, about 3 km to SW from Yen Lac village (N 22°44′ E 105°50′), about 42 km to NWW from Cao Bang town. Secondary evegreen wet closed broadleaved forest on alluvial foothills of limestone remnant ridge at 1250-1300 m alt. Herb vine up to 10 m lg in open place among secondary shrubs. Not rare.
CBL 381 18 Nov. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)