Birthwort (lat. Aristolochia clematitis) is a twining herbaceous plant with heart-shaped leaves and pale yellow flowers that are tubular in form. The plant seeks light by ascending the stems of surrounding plants. It is endemic throughout Europe and Asia; in Greece, it grows in Macedonia, Thrace, Epirus and Thessaly. 

It was formerly used as a medicinal plant, though it is poisonous and is now occasionally found established outside of its native range as a relic of cultivation.