Houphan Prov., Hem Distr., Na Puok village, Pu Tham Nhon mountain around point 20°10′00.0′'N 103°24′37.0′'E.
Primary and secondary broad-leaved evergreen dry forest on very steep rocky mountain slopes composed by solid marble-like highly eroded limestone at elev. 1050-1150 m a.s.l.
Scandent shrub 2-3 m tall on mossy rocks near mountain top. Flowers yellow. Very common.