The leaves and tops of Tanacetum vulgare.

Characters. - Leaves about six inches (15 centimetres) long; bipinna-tifid, the segments oblong, obtuse, serrate or incised, smooth, dark green, and glandular; flower-heads corymbose, with an imbricated involucre, a convex, naked receptacle, and numerous yellow, tubular florets; odour strongly aromatic; taste pungent and bitter.

Composition. - Tansy contains a powerful and irritating volatile oil.

Uses. - It is seldom used in regular practice. Fatal cases of poisoning from this drug have been reported, the symptoms being epileptiform convulsions and coma, feeble pulse and death. Its action thus resembles that of absinthe. It has been used as a diuretic and stimulant in rheumatism, ague, and hysteria, as an emmenagogue in amenorrhoea, and sometimes as an anthelmintic. It is generally given as an infusion.