N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Thanh Son Municipality, middle part of Pu Luong range, rocky isolated basalt peak on E macroslope of main ridge at point 20°28′32′'N, 105°05′35′'E. Primary evergreen seasonal broad-leaved closed submontane forest thickets on very steep slopes and on the peak top at elev. 1600 m. Lithophytic vine 3-4 m lg. F light pinkish. Occasional.