Common Name: Common Tansy
Scientific Name: Tanacetum vulgare
Habitat: disturbed areas, roadsides, grassland
Provincial Designation: Noxious
Noxious weeds are plant species designated in the Alberta Weed Control Act. Noxious weeds must be controlled, meaning their growth or spread needs to be prevented.
In the 1600s, common tansy was introduced to North America from Europe. Traditionally, its foliage has been used medicinally as an insect repellent and cooking.
Common tansy invades disturbed areas, roadsides and grassland and can form dense stands in these habitats. It contains alkaloids that are toxic to both humans and livestock if consumed in large quantities. Grazing livestock avoids common tansy if they can. Therefore, livestock poisoning is rare.
Common tansy has unique yellow, button-like flowers that are arranged in dense, flat-topped clusters at the end of the stems.
The leaves are pinnate and alternately arranged along the stem. Leaflets have deeply toothed edges — and the leaf has a somewhat ‘fernlike’ appearance. The stems are round, often purplish-red, and dotted with glands.
This plant can grow up to 150 cm high.
Tansy may contain a volatile oil that can cause contact dermatitis in sensitive people.
Goats can eat and control this weed. To find out more, check out Edmonton’s GoatWorks Project.
Learn more about this species:
See Fact Sheet - Alberta Invasive Species Council