FLORA OF VIETNAM Aristolochiaceae Aristolochia sp.
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.
Woody vine 6-8 m long in shady places on very steep, rocky slope. Flowers white with brown-purple. Rare.