Common Tansy

Common Tansy- This pungent perennial grows up to 5' tall and spreads via wind-dispersed seeds, as well as by rhizomes.

Leaves: Alternate and pinnately compound, they are deeply divided into toothed segments and become smaller towards the top of the stalk.

Flowers: Flowers bloom from July to October. Numerous clusters of button-like yellow flowers that have a flat top and are 1/4 to 1/2 inches wide.

Habitat: It is extremely common to find along roadsides, waste areas, stream banks and in pastures.

Weed Classification: B

Why is it a Noxious Weed?
Because of its aggressive nature and risk of toxicity to livestock. Like most other noxious weeds, it can displace good forage and reduce/jeopardize wildlife habitat.

This species is widely distributed throughout Lewis, and neighboring, Counties. The creation of containment areas is being evaluated.

Control Recommendations:
WA State Noxious Weed Board
King County Noxious Weed Board - Best Management Practices
PNW Pest Management Handbook
UC Davis Weed Report