N. Vietnam, Prov. Quang Binh, distr. Minh Hoa, 72 km to NWW from Dong Hoi, municipalite Thong Hoa, vicinities of Yen Son village, limestone massif Ke Bang (N 17°40′ E 105°57′). Primary evergreen broadleaved forest on steep slopes and bluffs of limestone mesas at 200-250 m alt. Creeping epiphytic vine up to 4 m lg. Leaves deep blue-green. Rare. VH 4605 15.05.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)