Aristolochia luudamcui (Aristolochiaceae), a new species from northern Vietnam

Aristolochia luudamcui (Aristolochia subgen. Siphisia, Aristolochiaceae), a new species from Vietnam, previously misidentified as A. utriformis, is described and illustrated here. The new species is most similar to A. pseudoutriformis and A. utriformis concerning the morphology of the leaf lamina, the color of the perianth, and the shape of the limb, but A. luudamcui can be distinguished from the other two species by having a deeply 3-lobed limb and a glabrous, yellow inner surface of limb lobes. A detailed description, information on ecology, phenology, distribution, usage, a provisional assessment of the conservation status of the new species, and a comparison with morphologically similar species are provided as well.