bull thistle: Cirsium vulgare (Asterales: Asteraceae)

bull thistle
Asterales > Asteraceae > Cirsium vulgare (Savi) Ten.
Synonym(s): common thistle, spear thistle
Bull thistle is an annual or biennial, herbaceous plant that invades disturbed areas throughout the United States. The spiny, spreading, winged stems are up to 7 ft. (2.1 m) tall. Leaves are 3-12 in. (7.6-30.5 cm) long, lance-shaped and very hairy. Flowers develop, at the apex of the plant, from June to September. The purple flower heads are 1.5-2 in. (3.8-5.1 cm) in diameter and 1-2 in. (2.5-5.1 cm) long with narrow, spine-tipped bracts. Bull thistle can invade almost any type of disturbed area, such as forest clearcuts, riparian areas and pastures. Plants can form dense thickets, displacing other vegetation. The spiny nature of the plant renders it unpalatable to wildlife and livestock and reduces the forage potential of pastures. Bull thistle is native to Europe, western Asia, and northern Africa. It is thought to have been introduced to the eastern United States during colonial times and the western United States in the late 1800s. It is currently found in all 50 states.

Identification, Biology, Control and Management Resources

Biological Control of Invasive Plants in the Eastern United States - USDA Forest Service FHTET

Fire Effects Information System - USDA Forest Service, Rocky Mountain Research Station

Invasive Plants and Exotic Weeds of Southeast Alaska - USDA Forest Service, Alaska Region

Selected Invasive Plants of Alaska - USDA Forest Service, Alaska Region

Weeds of the Week - USDA Forest Service, Northeastern Area, Forest Health Protection

Selected Images from Invasive.org

Click on each thumbnail to download the image at 1536x1024 resolution or below for available resolutions.

Use 768x512 for Microsoft PowerPoint and use 1536x1024 for Prints and Publications.

Foliage; Richard Old, XID Services, Inc., Bugwood.org 768x512 / 1536x1024	Foliage; Basal rosette Michael Shephard, USDA Forest Service, Bugwood.org 768x512 / 1536x1024	Foliage; Basal rosette Michael Shephard, USDA Forest Service, Bugwood.org 768x512 / 1536x1024
Plant(s); Richard Old, XID Services, Inc., Bugwood.org 768x512 / 1536x1024	Foliage; Steve Dewey, Utah State University, Bugwood.org 768x512 / 1536x1024	Foliage; Richard Old, XID Services, Inc., Bugwood.org 768x512 / 1536x1024
Foliage; Dan Tenaglia, Missouriplants.com, Bugwood.org 768x512	Plant(s); stem Dan Tenaglia, Missouriplants.com, Bugwood.org 768x512	Feature(s); Spines Steve Dewey, Utah State University, Bugwood.org 768x512 / 1536x1024
Flower(s); habit Forest & Kim Starr, U.S. Geological Survey, Bugwood.org 768x512 / 1536x1024	Flower(s); flowers Forest & Kim Starr, U.S. Geological Survey, Bugwood.org 768x512 / 1536x1024	Flower(s); flower Forest & Kim Starr, U.S. Geological Survey, Bugwood.org 768x512 / 1536x1024
Flower(s); close up Loke T. Kok, Virginia Polytechnic Institute and State University, Bugwood.org 768x512 / 1536x1024	Flower(s); Britt Slattery, U.S. Fish and Wildlife Service, Bugwood.org 768x512	Fruit(s); seeds Forest & Kim Starr, U.S. Geological Survey, Bugwood.org 768x512 / 1536x1024
Fruit(s); Forest & Kim Starr, U.S. Geological Survey, Bugwood.org 768x512 / 1536x1024	Plant(s); large mature plant on timber harvest area Dave Powell, USDA Forest Service, Bugwood.org 768x512 / 1536x1024	Plant(s); habit Forest & Kim Starr, U.S. Geological Survey, Bugwood.org 768x512 / 1536x1024
Plant(s); habit and flowers Forest & Kim Starr, U.S. Geological Survey, Bugwood.org 768x512 / 1536x1024	Plant(s); in flower Steve Dewey, Utah State University, Bugwood.org 768x512 / 1536x1024	Competition; under dead fir killed by budworm. Swale Creek, Under dead fir killed by western spruce budworm (ChorisÂ¬toneura occidentalis); Swale Creek, Heppner Ranger District, Umatilla National Forest, northeastern Oregon Dave Powell, USDA Forest Service, Bugwood.org 768x512 / 1536x1024
Fruit(s); Steve Hurst, USDA NRCS PLANTS Database, Bugwood.org 768x512 / 1536x1024	Diagram or Graphic; Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3: 549. USDA PLANTS Database, USDA NRCS PLANTS Database, Bugwood.org 768x512 / 1536x1024

Invasive Reference(s):

Check Invasive.org for most current lists.

Alabama - IPC List
California - Invasive Plant Inventory
Colorado - Noxious Weed Law
Georgia - EPPC list
Iowa - Noxious Weed Law
Maryland - Noxious Weed Law
Michigan - Noxious Weed Law
Minnesota - Noxious Weed Law
New Mexico - Noxious Weed Law
Oregon - Noxious Weed Law
Pennsylvania - Noxious Weed Law
Rhode Island - Noxious Weed Law
South Carolina - EPPC List
Tennessee - EPPC List
Texas - Invasive Plant List
Virginia - Invasive Alien Plant Species
Washington - Noxious Weed Law
Mid-Atlantic - EPPC List
Invasive Plants: Western North America
Invasive Plants of the Upper Midwest

Invasive Plants of the United States

bull thistle

Identification, Biology, Control and Management Resources

Selected Images from Invasive.org

Click on each thumbnail to download the image at 1536x1024 resolution or below for available resolutions.

Use 768x512 for Microsoft PowerPoint and use 1536x1024 for Prints and Publications.

Invasive Reference(s):

Check Invasive.org for most current lists.

External Links


				Bargeron, C.T., C.R. Minteer, C.W. Evans, D.J. Moorhead, G.K. Douce and R.C. Reardon. Technical Coordinators. 2008. Invasive Plants of the United States DVD-ROM: Identification, Biology and Control. USDA Forest Service. Forest Health Technology Enterprise Team. Morgantown, WV. FHTET-08-11.