N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Lam Xa Municipality, Lang Trang village, around point 20°20′02′'N, 105°12′39′'E. Secondary broad-leaved evergreen seasonal open forest on very steep slopes of hills and remnant mountains composed with solid crystalline marble-like highly eroded limestone at elev. 100-400 m a.s.l. Lithophytic herb up to 0.6 m tall on shady wet rocks. Flowers green. Common.