Common tansy is an aromatic, perennial herb native to Eurasia. Plants can reach to 5 ft. (1.5 m) in height and can be toxic to people and other animals if ingested in large quantities. Leaves are alternate, sessile or short-stalked, highly divided and glandular dotted. Flowering occurs from August to October, when yellow, button-like flowers develop in flat-topped clusters at the apex of the plant. Fruit are 5-angled achenes with small glands. Plants invade disturbed areas, ditch banks and riparian areas.