Birthwort

Aristolochia (English: ) is a large plant genus with over 500 species that is the type genus of the family Aristolochiaceae. Its members are commonly known as birthwort, pipevine or Dutchman's pipe and are widespread and occur in diverse climates. Some species, like A. utriformis and A. westlandii, are threatened with extinction. The genus Isotrema is usually included here as Aristolochia subgenus Siphisia, but might be a valid genus. It contains the species with a three-lobed calyx.