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). Primary broad-leaved evergreen forest on slope of remnant highly eroded karst limestone ridge at elev. 500 m a.s.l. Lithophytic herb up to 1 m hg on wet open mossy rocks. Leaves below violet, urticate. Very common.