Tansy (Fr. athanasie, contracted to tanai-sie, from Gr. θανασία, immortality, in allusion to some supposed preservative quality of the plant, or to its durable flowers), tanacetum vulgare, a plant of the composite family, a native of Europe, which was formerly cultivated, but has escaped from gardens and become a common roadside weed. It is a perennial herb, with large, twice or thrice pinnately divided, deep green leaves, and stems 2 to 4 ft. high, bearing corymbs of heads of golden yellow flowers, which are nearly all tubular and fertile. A variety called double tansy has the leaves more cut and crisped. The leaves have a strong fragrance, due to a volatile oil and a bitter, aromatic taste, and have long been in use infused in spirits as a domestic aromatic tonic; in former times it was held in much esteem as a remedy in dropsy, and as a worm-destroying medicine. The volatile oil is kept in the shops, and is popularly supposed to produce abortion; it is highly poisonous, and its use for criminal purposes has often killed the mother.
The green leaves were formerly used in cookery, but have been superseded by foreign spices, though tansy puddings are still made in England. - A native species, T. Huronense, found in Maine and on the great lakes, is only of botanical interest.
Tansy (Tanacetum vulgare).