N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality Thang Loi, vicinities of Lung Sam village (N 22°45′ E 106°42′). Secondary wet evergreen broadleaved forest with remnants of primary elements on steep slopes and bluffs of karst remnant limestone ridge at 550-600 m elev. Herb vine 4-5 m lg in open place. Common.
CBL 1681 24 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)