N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Co Lung Municipality, Khuyn village, around point 20o26′31′'N, 105o14′55′'E. Primary evergreen seasonal broad-leaved lowland forest on crystalline marble-like highly eroded limestone, steep rocky slopes of limestone ridge at elev. 500-800 m. Terrestrial and lithophytic herb. Flowers pink, leaves deep uniform green above, dull purple below. Occasional.