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. 600-700 m a.s.l. Lithophyte herb on crevices of vertical shady cliffs. Leaves deep green with light green venation above, dirty reddish-violet below. Flowers light green with pink base. Anthers yellow. Very common at 700-800 m a.s.l.