Houphan Prov., Viengxay Distr., Vieng Xai village, around point 20°23′41.3′'N 104°13′44.5′'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. 800-950 m a.s.l.
Scandent shrub 3 m tall in rather open place. Flowers white. Locally common.