N.Vietnam, Bac Kan Prov., Cho Don Distr., Ban Thi Municipality, village Phia Khao, around point 22°16′10′'N, 105°31′01′'E at elevation 700-850 m a.s.l. (Tang Gia mountain).
Primary broad-leaved evergreen closed forest on very steep slopes and cliffs near and on tops of rocky ridge composed with solid marble-like stratified limestone.
Woody vine 15-20 m long. Flowers white, later light yellow, very pleasant fragrant. Not common.