Thanh Hoa Prov., Thuong Xuan Distr., Bat Mot Municipality, Duc village, Xuan Lien Natural Reserve.
Primary broad-leaved evergreen forest along narrow ridge composed by shale at elevation 850-1150 m a.s.l. around point 20°01’50.4’’N 104°57’21.0’’E. Woody vine 5-7 m long in shady places along ridge edge. Common.