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. Terrestrial herb to 0.5 m tall on steep rocky slope. Flowers purple-violet. Common.