Why Is It a Noxious Weed?
Plumeless thistle invades pastures, meadows, and fields crowding out desirable forage plants. Livestock will not graze in areas heavily infested with plumeless thistle.
How would I identify it?
It is an upright, spiny, biennial growing up to 8 feet tall.
Flowers are solitary or in clusters of 2 to 3 flower heads with reddish purple flowers.
Dark green leaves are deeply lobed to compound with hair on the undersides and spines along the leaf margins.
Stems are tough and have spiny wings.
Fruit Seed Description
Seeds (achenes) are smooth and hairless.
Where does it grow?
Plumeless thistle grows in pastures, stream valleys, fields and roadsides. Please click here to see a county level distribution map of plumeless thistle in Washington.
How Does it Reproduce?
Plumeless thistle reproduces by seed.
How Do I Control It?
General Control Strategy
Establishing a dense, well-maintained pasture is effective in preventing a plumeless thistle infestation.
Plumeless thistle can be dug or grubbed out.
For More Information
See our Written Findings for more information about plumeless thistle (Carduus acanthoides).
Stevens County NWCB Fact Sheet on plumeless thistle