Centaurea calcitrapa

Centaurea calcitrapa_purple starthistle_flowering head_JM DiTomaso
Photo courtesy Joseph DiTomaso

Common names: purple starthistle

Centaurea calcitrapa (purple starthistle) grows as an annual, biennial or perennial (family Asteraceae) in fields, roadsides, disturbed open sites, grasslands, overgrazed rangelands, and logged areas in the northern and central coast ranges of California. Centaurea species may produce allelopathic effects and are highly competitive with other plants, often displacing desired vegetation.

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

  • Butler, E. and S. Britting (1998). Mapping and control of weeds in the American River Parkway. California Exotic Pest Plant Council Symposium '98. Ontario, CA.
  • Carrithers, V. F. (1997). Using Transline* herbicide to control invasive plants. California Exotic Pest Plant Council Symposium '97. Concord, CA.
  • Cooper, V. K. and B. J. Moritsch (1999). Weeding the wilderness: Non-native plant management at Point Reyes National Seashore. California Exotic Pest Plant Council Symposium '99. Sacramento, CA.
  • DiTomaso, J. M. (1995). Overview of extension non-crop weed research in California. California Exotic Pest Plant Council Symposium '95. J. Lovich, J. Randall and M. Kelly. Pacific Grove, CA.
  • DiTomaso, J. M. (1997). Risk analysis of various weed control methods. California Exotic Pest Plant Council Symposium '97. Concord, CA.
  • DiTomaso, J. M., C. Benefield, et al. (1998). Reproductive biology of yellow starthistle (Centaurea solstitialis) maximizing late season control. California Exotic Pest Plant Council Symposium '98. Ontario, CA.
  • DiTomaso, J. M., G. B. Kyser, et al. (1998). Prescribed burning for control of yellow starthistle (Centaurea solstitialis) and enhanced native plant diversity. California Exotic Pest Plant Council Symposium '98. Ontario, CA.
  • Gluesenkamp, D. (2003). Marin-Sonoma Weed Management Area: Putting the ‘we’ in weed management. California Invasive Plant Council Symposium 2003. Kings Beach, CA.
  • Rusmore, J. T. (1995). Use of fire and cutting to control yellow starthistle. California Exotic Pest Plant Council Symposium '95. M. Kelly and J. Lovich. Pacific Grove, CA.
  • Young, J. A., C. D. Clements, et al. (2000). Purple starthistle seed germination. California Exotic Pest Plant Council Symposium 2000. M. Kelly. Ontario, CA.

Cal-IPC News Articles

  • (1993). California Exotic Pest Plant Council draft list exotic plants of greatest concern October 1993. CalEPPC News. 1: 6.
  • DiTomaso, J. (1998). Results of the CalEPPC questionnaire at Symposium '98 in Ontario. CalEPPC News. 6: 4.
  • Pitcairn, M. (2000). All weeds that have approved biological control agents, accidental introductions and others. CalEPPC News. 8.