N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Thanh Son Municipality, middle part of Pu Luong range, SE slope of Phu Pha Phong peak around point 20°28′37′'N, 105°05′20′'E. Primary evergreen seasonal broad-leaved closed submontane forest on basalt along main ridge at elev. 1600-1650 m. Terrestrial creeping herb up to 0.5 m tall. Very common.