N. Vietnam, prov. Ha Giang, distr. Yen Minh, municipality Du Gia, E slopes of Phu Tha Ca mountain system at 900-1000 m elev. (N 23°56′ E 105°13′). Primary evergreen broadleaved very wet mountain forest on shale very steep slopes. Herb vine 3-4 m in open place. Flowers white. Common.
CBL 2046 03 May 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)