European birthwort or heartwort (Aristolochia clematitis) is a perennial plant and grows to a height of between 30 and 70 centimetres. Its main flowering period lasts from April to June. In locations that are mown, it can still flower in September.
All parts of the plant are poisonous and contain aristolochic acid.
The natural distribution area includes most European countries. In Asia it extends as far as the Caucasus and western Asia. It also occurs as a naturalised plant in some North American regions (distribution map).
Aristolochia clematitis grows on the edges of fields and bushes, in sparse forests and vineyards. It does best in sunny and warm locations. The soil should be humus-rich to slightly loamy.
