Houphan Prov., Viengxay Distr., Khang Pa Pong village, around point 20°19′41.4′'N 104°25′10.6′'E.
Primary and secondary broad-leaved evergreen dry forest on very steep rocky slopes of highly eroded mountains composed by solid marble-like limestone at elev. 1000-1100 m a.s.l.
Woody vine 6-8 m long and 10-12 cm in diam. on mountain slope. Flowers white. Common.