And where the marjoram once, and sage, and rue,
And balm, and mint, with curl’d-leaf parsley grew,
And double marigolds, and silver thyme,
And pumpkins ‘neath the window climb;
And where I often, when a child, for hours
Tried through the pales to get the tempting flowers,
As lady’s laces, everlasting peas,
True-love-lies-bleeding, with the hearts-at-ease,
And golden rods, and tansy running high,
That o’er the pale-tops smiled on passers-by.
John Clare
This common perennial of Eurasia was brought to North America during Colonial times to treat intestinal, parasitic worms. During Medieval times it was a wise woman ‘cure’ for pregnancy, since the present thujone in high enough does will cause abortion! Although most of common Tansy’s medicinal uses have been discredited, it is still a component of some medicines in the early 21st century and is listed by the United States Pharmacopeia as a treatment for fevers, feverish colds, and jaundice.
Tansy was used in a type of embalming of the dead, for repelling of various insects. It has also been used directly as an insect repellent. Tansy was used as a skin cleanser to lighten the complexion.
Tansy can be toxic. Sheep and goats eat this plant with relish, but cattle and horses only eat it when young. The plant is less palatable and more toxic as it matures. Thujone is the active toxin, and may cause stomach pain, mental/mood changes, trouble sleeping, tremors, change in the amount of urine, seizures, numbness, unusual thirst.
Although Tansy is toxic, it has been used for culinary reasons for centuries. Cooking the plant causes the toxicity to be eliminated. The flower buds have a flavor suggesting ginger and are either loved or reviled. Back in the day Tansy and caraway seed biscuits were served at funerals.