Weed Department
Idaho State Noxious 
Weed Law
Plumeless Thistle


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.


Interesting Facts:

Plumeless thistle invades pastures, meadows, and fields crowding out desirable forage plants. Livestock will not graze in areas heavily infested with plumeless thistle.