Tanacetum

Tanacetum 

(tansy), a genus of perennial herbaceous plants of the family Compositae. The alternate leaves are pinnatisect or, less frequently, pinnately lobed. The cup-shaped heads generally form cymose inflorescences; less frequently, they are solitary. There are a few pistillate, yellow, tubular ray-florets (or ligulate ray-florets with very short ligules) and numerous bisexual tubular disk-florets. The naked acheen have five to ten longitudinal ribs and a short dentate or lobed crown.

There are more than 50 species of Tanacetum, distributed in nearly all the nontropical countries of the northern hemisphere. The USSR has 34 species. Some species are cosmopolitan, while others are found only in the mountains of the Caucasus and Middle Asia. Common tansy (T. vulgare) grows throughout the USSR except in the Far North and desert areas. It grows near dwellings, along roads, in meadows and forest glades, and along rivers. Its leaves and heads contain volatile oils, flavonoids, tannins, and alkaloids. The plants are used medicinally as an anthelmintic, and a powder derived from them is used as an insecticide. The plants are toxic to cattle. Sometimes the genus Tanacetum is combined with the genera Pyrethrum and Chrysanthemum.

T. G. LEONOVA