N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Co Lung Municipality, Khuyn village, around point 20°26′39′'N, 105°15′33′'E. Primary evergreen seasonal broad-leaved forest on slope of schist/shale Nam Khanh river valley at foothill of crystalline marble-like highly eroded limestone ridge at elev. 50-70 m. Terrestrial herb up to 0.5 m tall. Abundant.