Tannacetum vulgare L. - Common tansy
FAMILY: Compositae (Asteraceae)—the Daisy Family (see Arctium)
PHENOLOGY: Tansy is a late-season flowering plant, commonly blooming August through October.
DISTRIBUTION: This Old World perennial is found along roadsides, in fields and waste places, and is cultivated in herb and medicinal gardens.
PLANT CHARACTERISTICS: Tanacetum vulgare can he identified by its coarse, aromatic foliage arising from a stout rhizome. The leaves are numerous, 1-2 dm long, nearly half as wide, sessile, punctate, pinnatifid, with an evidently winged rachis; leaflets: toothed or incised; flower heads: many, corymbose, 20-200 disk flowers per head; disks: 5-10 mm wide, golden-yellow, 5-toothed; pappas: minute, a 5-lobed crown.
POISONOUS PARTS: The herbage (leaves and stems) and flowers contain the toxin.
SYMPTOMS: Severe gastroenteritis, rapid and weak pulse, violent spasms, convulsions, and death have resulted from overdose of tansy.
POISONOUS PRINCIPLES: The source of poisoning is an oil, tanacetin.
CONFUSED TAXA: Tansy resembles the pineapple weed (Matricaria matricarioides (Less.) Porter), which is an annual, glabrous, pineapple-scented plant with 4-toothed corolla disks. Tansy also resembles costmary (Chrysanthemum Balsamita L.), which has simple silvery-strigose leaves.
SPECIES OF ANIMALS AFFECTED: The pungent, strong smell of the herbage usually prevents animals from consuming this plant in quantity. Human life has been lost after abuse of medicinal extracts from tansy. Oil of tansy is used as a cure for nervousness, to induce abortion, to foster menstruation, or to kill worms (antibelminthic) in home remedies. Teas made from the herbage can be lethal.
TREATMENT: (11a)(b): (26)