N. Vietnam, Thanh Hoa prov., Ba Thuoc distr., Co Lung municipality, territory of Pu Luong protected area, near Co Lung village (20°27′28′'N, 105°12′18′'E). Secondary open forest and shrubs on clay alluvial foothills of remnant highly eroded karst limestone ridge at elev. 400-500 m a.s.l. Rare.