N. Vietnam, prov. Cao Bang, distr. Nguyen Binh, municipality Ca Thanh, vicinities of Ta Phinh village (N 22°44′ E 105°50′). Secondary open broadleaved forest on steep slopes and bluffs of remnant karst limestone ridge at 1200-1250 m elev. Herb vine up to 2-3 m lg in open place. Flowers greenish-white. Not rare.
CBL 1575 19 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)