N. Vietnam, Hoa Binh prov., Mai Chau distr., Hang Kia municipality, near Hang Kia village, (20°44′21′'N, 104°53′57′'E). Primary wet broad-leaved evergreen closed forest on of highly eroded remnant karst limestone ridge at elev. 1100-1200 m a.s.l. Terrestrial herb up to 0.5 m hg on steep rocky slope. Very common. Usual codominante of herb forest stratum.