N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Thanh Son Municipality, SW macroslope of middle part of Pu Luong range around point 20°28′30′'N, 105°05′16′'E. Primary evergreen seasonal broad-leaved closed submontane forest on basalt at elev. 1500-1550 m. Climbing shrub or woody vine 3-4 m lg on wet open cliff. Very common.