N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Thanh Son Municipality, middle part of Pu Luong range to the W of Long Bong village (20°27′52′'N, 105°07′36′'E). Primary evergreen seasonal broad-leaved closed submontane forest on basalt along main ridge at elev. 1200-1400. Terrestrial herb up to 1 m tall. Flowers pink-purple. Leaves uniform green on both sides. Common.