N. Vietnam, Thanh Hoa prov., Ba Thuoc distr., Eo Dieu municipality, territory of Pu Luong protected area, near Eo Dieu village (20є25'48''N, 105є14'13''E). Primary wet broad-leaved evergreen forest on very steep slopes of remnant highly eroded karst limestone ridge at elev. 600-700 m a.s.l. Epiphyte. Flowers: tepals white, lip yellow