Beschreibung:
<jats:p><jats:italic>Isotrema putalengense</jats:italic> Luu, Q.B.Nguyen & H.C.Nguyen is described as a new species from northern Vietnam. It looks most morphologically like <jats:italic>I. wardianum</jats:italic> but is distinguishable by a combination of different leafy and floral characters. Morphological comparison between the new plant and closest species is provided. In addition, combinations of two recently described <jats:italic>Aristolochia</jats:italic> species are made, namely <jats:italic>Isotrema vuquangense</jats:italic> (T.V.Do) Luu, Q.B.Nguyen & H.C.Nguyen and <jats:italic>Isotrema yachangense</jats:italic> (B.G.Huang, Yan Liu & Y.S.Huang) Luu, Q.B.Nguyen & H.C.Nguyen.</jats:p>