Tansy

Tansy is a perennial herbaceous flowering plant in the genus Tanacetum and family Asteraceae, native to temperate Europe and Asia and also known as common tansy, bitter buttons, cow bitter or golden buttons. It grows 50 to 150 centimetres tall on an erect, often reddish stem, with finely divided compound leaves and clusters of small, yellow, button-like flowerheads 7 to 12 millimetres across that bloom from around July to September in Great Britain. The species has spread well beyond its native range into Australia and the Americas, where it has become invasive in places.