Plumeless Thistle

Carduus acanthoides

Plumeless Thistle

Family: Asteraceae

Other Common Names: spiny plumeless thistle
Weed class: B
Year Listed: 1988
Native to: Europe and temperate Asia
Is this Weed Toxic?:

not known to be


Legal listings:

WA Quarantine list, WAC 16-750

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?

General Description

It is an upright, spiny, biennial growing up to 8 feet tall.

Flower Description

Flowers are solitary or in clusters of 2 to 3 flower heads with reddish purple flowers.

Leaf description

Dark green leaves are deeply lobed to compound with hair on the undersides and spines along the leaf margins.

Stem description

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.

Mechanical Control

Plumeless thistle can be dug or grubbed out.

Herbicide Control

Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

For More Information

See our Written Findings for more information about plumeless thistle (Carduus acanthoides).

Stevens County NWCB Fact Sheet on plumeless thistle

Additional Photos