N.Vietnam, Bac Kan Prov., Ba Be Distr., Nam Mau Municipality, Ba Be National Park around point 22025′34′'N 105036′03′'E. Secondary closed evergreen broad-leaved forest on slopes of remnant mountains composed with crystalline highly eroded marble-like limestone at elevation 300 m a.s.l.
Vine up to 8 m long. Very common.
HLF 528 21 Dec. 2002. Photo.
Coll. Phan Ke Loc, L.Averyanov, Hoang Van Chat, Do Hoang Chung, Nguyen Manh Hung, Vu Hong Van, Nguyen Tien Vinh, Mai Van Xinh. Grant from Henry Luce Foundation.