N. Vietnam, Thanh Hoa prov., Ba Thuoc distr., Eo Dieu municipality, territory of Pu Luong protected area, near Eo Dieu village (20°25′48′'N, 105°14′13′'E). Primary wet broad-leaved evergreen forest on very steep slopes of remnant highly eroded karst limestone ridge at elev. 500-600 m a.s.l. Terrestrial and lithophyte herb in wet places. Flowers red-purple, lip pink with white at base and yellow center, spur white, lip inside with bright red-purple lateral pinnate stripes. Common.