N.Vietnam, Thanh Hoa Prov., Ba Thuoc Distr., Thanh Son Municipality. Schist/shale foothills of Pu Luong range around point 20°28′N, 105°05′E at elev. 60-100 m. Secondary shrubs along river. Herb or semishrub 1-1.5 m tall in open places along road. Flowers yellow. Very common.