N. Vietnam, Hoa Binh prov., Mai Chau distr., Hang Kia municipality, near Hang Kia village (20°43′39′'N, 104°53′43′'E). Primary broad-leaved evergreen wet forest on slopes of remnant limestone highly eroded ridge at elev. 1100-1200 m a.s.l. Shrub 1.5-2 m hg on wet rocky place. Flowers light greenish. Not rare.