bull thistle

(Cirsium vulgare)

Conservation Status
bull thistle
  IUCN Red List

not listed


NNA - Not applicable

SNA - Not applicable


not listed

Weed Status

Prohibited Weed Seed

County Noxious Weed in Clay, Koochiching, Lincoln, Waseca, and Yellow Medicine Counties.

Bull thistle is listed as an invasive terrestrial plant by the Minnesota Department of Natural Resources. It is not considered as serious a threat as other invasive thistles. The spiny foliage makes it unpalatable to wildlife and livestock. It reproduces by seed only, not vegetatively. About 95% of the seeds germinate but few plants survive to maturity. Seeds that do not germinate in the first spring do not survive the following winter unless they are buried. Seeds that are buried at least 5 inches, as in cropland under cultivation, remain viable for only 3 years.

Wetland Indicator Status
  Great Plains

UPL - Obligate upland


FACU - Facultative upland

  Northcentral & Northeast

FACU - Facultative upland


Bull thistle is a 16 to 78 tall, erect, biennial forb that rises from a taproot and fibrous roots. The taproot is fleshy, thick, up to 28 deep, and often branched.

In its first year the plant produces a radiating cluster of leaves (rosette) above ground and a large taproot below ground. In the second year it sends up a single erect flowering stem, sometimes also one or more ascending side stems. The plant dies after flowering and setting seeds one time. It does not spread vegetatively. The seeds germinate easily but do not often survive. As a result plants are usually found singly or scattered.

The stem is stout, usually well branched, and light green with dark purple veins. It is sparsely to densely covered with long, soft, spreading hairs, at least the middle and upper sections. The upper portion of the stem is conspicuously winged. The sap is clear, not white.

The rosette of basal leaves produced in the first year is flat and can be 24 or more in diameter. The leaves are narrowly elliptic to inversely lance-shaped in outline, 6 to 16 long, and 1¼ to 6 wide. They are deeply cut into 4 to 6 widely spaced pairs of lobes (pinnatifid) with the lobes further cut into 3 or 4 smaller lobes (bipinnatifid). The ultimate lobes are rigid, triangular to lance-shaped, and tipped with a stout, yellowish, 1 16 to long spine. They extend both horizontally and vertically from the plane of the leaf blade and are mostly twisted at the base to face toward the leaf tip, giving the leaf a distinct three-dimensional appearance. The upper surface is dark green with a light green midrib. It is covered with short, straight, white hairs and small yellowish spines. The lower surface is lighter green and is covered with grayish, cobwebby hairs, at least along the veins. The leaves are densely hairy when young and become less hairy as they mature. The margins are spiny.

Stem leaves are 1¼ to 6 long; stalkless and slightly clasping; and deeply lobed, cut more than half way to the midrib. The lobes are narrow, often linear lance-shaped. The upper surface is covered with stiff, bristly hairs, at least along the veins. Stem leaves are otherwise similar to basal leaves. The blade of the leaf continues down the stem from the point of attachment as a wing that is up to wide. The margins of the wings are armed with spines up to ¼ long. The wing extends uninterrupted nearly to the leaf below. Middle stem leaves are often more deeply divided than lower leaves. The leaves become progressively smaller but no less divided as they ascend the stem. However, some of the uppermost leaves may be lance-shaped or linear and not divided.

The inflorescence is usually a single large flower head, sometimes a loose, branched, cluster (corymb) of 2 to a few large flower heads, at the end of the stem and each branch. The flower heads are stalkless or are borne singly on to 2 long stalks. The flower heads are subtended by one to several straight, unlobed, linear, spine-tipped, bract-like leaves.

At the base of each flower head there are 5 to 12 rows of numerous bracts (phyllaries) forming a hemispheric or bell-shaped base (involucre). The involucre is 1¼ to 1½ long and ¾ to 1½ wide, slightly longer than wide. It is loosely covered with cobwebby hairs, at least near the base. The lower and middle phyllaries are linear lance-shaped, curve outwards, and are long tapered to a spiny, straw-colored, 1 16 to 3 16long tip. The inner phyllaries are linear.

The flower heads are to 1½ to 2 in diameter. They have numerous tubular, 1 to 1 long disk florets. The disk florets are reddish-purple or purple, rarely white.

The fruit is a to 3 16 long seed capsule (cypsela). The cypsela is light brown and sometimes has dark longitudinal streaks. The collar near the tip is inconspicuous. There is a tuft of white or light tan hairs at the tip.




16 to 78


Flower Color




Similar Species


Moist to dry. Prairies, pastures, abandoned fields, forest openings, roadsides, railroads, disturbed sites. Full sun.




Late June to August


Pests and Diseases






Distribution Map



2, 3, 4, 5, 7, 22, 24, 28, 29, 30.




Native of Northern Africa, Asia, and Europe. Introduced in the United States; naturalized.

The exact date and location of this species’ introduction is not known. It is thought to have been introduced into North America by European settlers, possibly as a seed contaminant, in the early 1800s.




Common and widespread

  Kingdom Plantae (green algae and land plants)  
  Subkingdom Viridiplantae (green plants)  
  Infrakingdom Streptophyta (land plants and green algae)  
  Superdivision Embryophyta (land plants)  
  Division Tracheophyta (vascular plants)  
  Subdivision Spermatophytina (seed plants)  
  Class Magnoliopsida (flowering plants)  
  Superorder Asteranae  


Asterales (sunflowers, bellflowers, fanflowers, and allies)  


Asteraceae (sunflowers, daisies, asters, and allies)  
  Subfamily Carduoideae (thistles and allies)  
  Tribe Cardueae  
  Subtribe Carduinae (thistles and burdocks)  
  Genus Cirsium (plume thistles)  

Subordinate Taxa






Carduus lanceolatus

Carduus vulgaris

Cirsium lanceolatum

Cirsium lanceolatum var. hypoleucum


Common Names


bull thistle

common thistle

spear thistle



















Twice pinnatifid. Cut deeply into lobes with each lobe also cut into deep lobes.



Modified leaf at the base of a flower stalk, flower cluster, or inflorescence.



Describing a leaf that wholly or partly surrounds the stem but does not fuse at the base.



A flat-topped or convex inflorescence in which the stalked flowers grow upward from various points on the main stem to approximately the same horizontal plane. The outer flowers open first.



A dry, one-chambered, single-seeded fruit, formed from a single carpel, with the seed attached to the membranous outer layer (wall) only by the seed stalk; the wall, formed from the wall of the inferior ovary and also from other tissues derived from the receptacle or hypanthium, does not split open at maturity, but relies on decay or predation to release the contents.



A whorl of bracts beneath or surrounding a flower or flower cluster.



Long, straight, and narrow, with more or less parallel sides, like a blade of grass.



An individual bract within the involucre of a plant in the Asteraceae family.



Deeply cut, more than half way to the midrib but not to the midrib, into lobes that are spaced out along the midrib; the lobes do not form separate leaflets.



A radiating group or cluster of leaves usually on or close to the ground.



A thin, flat, membranous, usually transparent appendage on the margin of a structure.




Visitor Photos

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Robert Briggs



    bull thistle   bull thistle  

Bill Reynolds


Here are two images of Bull Thistle just before bloom In Pennington Co. MN.

    bull thistle   bull thistle  


    bull thistle   bull thistle  
MinnesotaSeasons.com Photos


    bull thistle      

Basal Rosette

    bull thistle      

Basal Leaves

    bull thistle   bull thistle  
    bull thistle      


    bull thistle      


    bull thistle   bull thistle  

Winged Stem

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  Spear Thistle
Wez Smith
  Spear Thistle  

Spear Thistle (Cirsium vulgare).

  Cirsium vulgare
Matt Lavin
  Cirsium vulgare  

Introduced taprooted biennial often over 1 m tall, both leaf surfaces typically greenish and not covered by dense woolly hairs, upper leaf surfaces covered by minute spines or prickles, common where disturbance is frequent, such as roadsides and pastures.

  Bull Thistle (Spear Thistle) (Cirsium vulgare)
Andree Reno Sanborn
  Bull Thistle (Spear Thistle) (Cirsium vulgare)  
  Cirsium vulgare BULL THISTLE
Frank Mayfield
  Cirsium vulgare BULL THISTLE  



Visitor Videos

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Other Videos
  Identifying Bull Thistle, Cirsium vulgare

Uploaded on Jan 2, 2012

How to identify Bull Thistle, Cirsium vulgare, also known as Spear Thistle or Common Thistle. www.mynatureapps.com

  Bull Thistle (Cirsium vulgare) ~ Invasive Species
Wandering Sole TV

Published on Feb 10, 2014

Bull Thistle (Cirsium vulgare), also known as Spear Thistle, in the East Kootenays of British Columbia. It is a native plant of most of Europe, Western Asia, and NW Africa. In North America and Australia it has become naturalised and is a widespread weed often found colonising disturbed ground. It is a member of the Sunflower (Asteraceae) family. The flowers are a favourite with bees and butterflies (and on this day, ants).

Lacking natural predators and diseases, invasive plant species grow and spread rapidly throughout native ecosystems. Once established, invasive plants are very difficult to control and they choke out native species. This greatly affects wildlife habitat and rangeland. On a global scale, invasive pant and animal species are considered to be the second largest contributor to the loss of biodiversity, next to the loss of habitat.

  Environmental Laboratory - U.S. Army Corps of Engineers

Published on Feb 15, 2013

Cirsium vulgare - Bull Thistle

  Weed of the Week #654-Bull Thistle (Air Date 10/17/10)

Uploaded on Oct 20, 2010

Don't sit on this weed. No, really, don't SIT on this weed. It's our Weed of the Week, Bull Thistle.

  Spear Thistle (Cirsium Vulgare) - 2012-07-13

Published on Jul 16, 2012

Cirsium vulgare (Spear Thistle) is a species of the genus Cirsium.

De speerdistel (Cirsium vulgare, synoniem: Cirsium lanceolatum) is een plant uit het geslacht vederdistel.
52.05141 4.41610




Visitor Sightings

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  Bill Reynolds

Location: Pennington Co. MN

I didn't know these existed.  The Bull Thistle is just starting to bloom here in the north west of Minnesota.  The first two open are white.

bull thistle  
  Bill Reynolds

Location: Pennington Co. MN

Bull Thistle just before bloom In Pennington Co. MN.

bull thistle  
  Bill Reynolds

Location: Pennington Co. MN

Bull Thistle just before bloom In Pennington Co. MN.

bull thistle  
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