N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Co Lung Municipality, Eo Dieu village, around point 20°25′56′'N, 105°14′12′'E. Primary evergreen seasonal broad-leaved and coniferous submontane forest on crystalline marble-like highly eroded limestone, very steep upper slopes and tops of limestone rocky ridge at elev. 800-850 m. Climbing shrub or vine 1.5-2.5 m lg. Very common.