Vietnam, Ha Giang Prov., Bac Me Distr., Phieng Luong Municipality, about 1.5 km to NE of Phieng Luong Municipality headquarter (22º39’29’’N, 105º19’35’’E). Secondary open shrubs along road on steep slopes at the base of ridges composed with solid highly eroded crystalline limestone and shale at elev. about 800-850 m a.s.l.