Cirsium vulgare

Cirsium vulgare_bull thistle_flowering stem_JM DiTomaso
Photo courtesy Joseph DiTomaso

Synonyms: Carduus lanceolatus, Cirsium lanceolatum

Common names: bull thistle

Cirsium vulgare (bull thistle) is a perennial or biennial forb (family Asteraceae) Bull thistle is widespread in California and is most common in coastal grasslands, along edges of fresh and brackish marshes, and in meadows and mesic forest openings in the mountains below 7,000 feet (2,120 m). It is most troublesome in recently or repeatedly disturbed areas such as pastures, overgrazed rangelands, recently burned forests and forest clearcuts, and along roads, ditches, and fences. Besides out-competing native plant species for water, nutrients, and space, the presence of bull thistle in hay decreases feeding value and lowers market price.

Rating: Moderate

Cal-IPC Resources

  • Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.
  • CalWeedMapper - Statewide maps, climate models, and reports.
  • Cal-IPC News - Our quarterly newsletter. Each issue is available as a pdf.
  • Cal-IPC Symposium Proceedings - Presentations and papers from our annual Symposium.
  • Don't Plant a Pest! - Select your region to find non-invasive alternatives to ornamental species. Also see our statewide brochure on trees.

Other Resources

Symposium Presentations

  • Carrithers, V., B. Miller, et al. (2005). Aminopyralid: A new reduced risk active ingredient for control of broadleaf invasive and noxious weeds. California Invasive Plant Council Symposium 2005. Chico, CA.
  • Carrithers, V. F. (1997). Using Transline* herbicide to control invasive plants. California Exotic Pest Plant Council Symposium '97. Concord, CA.
  • Clines, J., J. DiTomaso, et al. (2004). Fire working group. California Invasive Plant Council Symposium 2004. Ventura, California, CA.
  • Connick, S. and M. Gerel (2004). Partnering to prevent invasions of plants of horticultural origin. California Invasive Plant Council Symposium 2004. Ventura, CA.
  • Donaldson, S., W. West, et al. (2003). Getting the job done: Working within the regulatory environment at Lake Tahoe to manage weeds. California Invasive Plant Council Symposium 2003. Kings Beach, CA.
  • Gluesenkamp, D. A. (2000). Factors controlling the relative abundance of two thistle species: Evaluating non-exclusive hypotheses for success of an introduced invader. California Exotic Pest Plant Council Symposium 2000. Concord, CA.
  • Pickart, A. (2003). A decade of dune restoration at the Lanphere Dunes. California Invasive Plant Council Symposium 2003. Kings Beach, CA.
  • Pirosko, C. and S. Schoenig (2004). Forbs working group. California Invasive Plant Council Symposium 2004. Ventura, CA.

Cal-IPC News Articles

  • Weed Science Society of America (2009). Feed the birds, but don't spread weeds. Cal-IPC News. 17: 12.
  • (1993). California Exotic Pest Plant Council draft list exotic plants of greatest concern October 1993. CalEPPC News. 1: 6.
  • Connick, S. and M. Gerel (2005). Don't sell a pest: A new partnership to prevent plant invasions through horticulture. Cal-IPC News. 13: 4-5,14.
  • Donaldson, S. (2003). Fighting weeds in the Tahoe basin. CalEPPC News. 11: 7.
  • Perala, C., D. A. Hoover, et al. (1993). Control of exotic plants in an herbaceous understory. CalEPPC News. 1: 4-6.
  • Pitcairn, M. (2000). All weeds that have approved biological control agents, accidental introductions and others. CalEPPC News. 8.