Woolly Distaff Thistle

Carthamus lanatus

Yellow flower coming out of a cluster of spiky leaves

Photo Credit: Joseph M. DiTomaso, University Of California Davis, Bugwood.org

Small bush with several spiky leaves and yellow flowers

Photo Credit: Joseph M. DiTomaso, University Of California Davis, Bugwood.org

Plant Description

Woolly distaff thistle is an erect winter annual with rigid stems. It flowers from July through August. It grows up to 3½ feet tall, has spiny pointed leaves that are alternate. The flower head has many long, sharp leaf-like bracts just below the yellow flowers. The rigid stems with old flower heads and leaves often persist through winter and often longer.

Plant Details

Life Forms	Forb
Habitats	Grasslands & Oak Savannas
ODA Listing	A
Soil and Moisture Conditions	Dry
Suggested Actions	Report to Oregon Invasives Hotline
Shade Preference	Full sun
Mature Height	3-4'
Distribution	Found sporadically along the west coast.
Control	Mow to prevent seed heads. Dig out roots or apply herbicides for a more sucessful removal, but must be maintained.
Disposal Methods	Remove seed heads and bag. Bag and throw away plants when dug out.
Reproduction and Spread	Spread through Waterways and hay crops.
Introduced	Discovered in Oregon in1987
Look Alikes	Smooth distaff thisthle
Impact	Unable to be grazed, this species overtakes grasses and outcompetes more palitable species.
More Info	https://www.invasiveplantatlas.org/subject.html?sub=5240 https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=7113 https://www.cal-ipc.org/plants/profile/carthamus-lanatus-profile/