Thanh Hoa Prov., Thuong Xuan Distr., Van Xuan Municipality, Hang Cao village, Xuan Lien Natural Reserve.
Remnants of primary and secondary broad-leaved evergreen forest on highly eroded rocky limestone hills at elevation 100-200 m a.s.l. around point 19°50′47.2″N 105°14′42.7″E.
Herbaceous vine 8-10 m long on alluvial slope at the bottom of limestone hill. Not common.