TANACETUM, TANSY, in botany: A genus of plants belonging to the class of synzemia, and order of poligamia superflua; and in the natural system ranging under the 49th order, Compositæ. The receptacle is naked; the pappus somewhat emarginated; the calyx imbricated and hemispherical; the florets of the radius are trifid, and scarcely distinguishable. Gmelin has enumerated seven species; of which one only is a native of Britain, the vulgare.
The vulgare, or common tansy, grows three or four feet high; the leaves are bipinnated and ferrated; the flowers yellow, and terminate the branches in flat umbels. It is found sometimes on the borders of fields and dry banks: it abounds at Wark, and Ford-castle in the neighbourhood of Kelsa, on the borders of Scotland; and on the side of Gareloch on the western coast of Ross-shire: it has also been found in Breadalbane. It flowers generally in August. Of this species there is a variety with curled leaves, which is therefore called curled tansy. The tansy has a bitter taste, and an aromatic smell disagreeable to many people.
Uset. It is esteemed good for warming and strengthening the stomach; for which reason the young leaves have obtained a place among the culinary herbs, their juice being an ingredient in puddings, &c. It is rarely used in medicine, though extolled as a good emmenagogue. A drachm of the dried flowers has been found very beneficial in hysterical disorders arising from suppression. The seeds and leaves were formerly in considerable esteem for destroying worms in children, and are reckoned good in colics and flatulencies. In some parts of Sweden and Lapland, a bath with a decoction of this plant is made use of to assist parturition. See PHARMACY, n° 193.