N.Vietnam, Cao Bang Prov., Trung Khanh Distr., Ngoc Khe Municipality, Pac Nga village, around point 22°54′59′'N, 106°31′44′'E, at elevation 700-750 m a.s.l.
Secondary wet closed evergreen forest on steep rocky slopes of rocky ridges and mesae composed with light gray solid marble-like highly eroded crystalline limestone.
Woody epiphytic and lithophytic vine 4-6 m long. Flowers white, disk pink. Common.