N.Vietnam, Thanh Hoa Prov., Quan Hoa Distr., Phu Le Municipality, Hang village, around point 20°32′29′'N, 105°04′32′'E. Primary evergreen seasonal broad-leaved closed lowland forest on tops of rocky ridge composed with crystalline marble-like highly eroded limestone at elev. 800-850 m. Woody grass 3-5 m tall. Very common. Usual co-dominant in open places.