Common names: Italian thistle
Carduus pycnocephalus (Italian thistle) is a winter annual forb (family Asteraceae) widely distributed in disturbed open sites, roadsides, pastures, annual grasslands, and waste areas in much of California.Cal-IPC Rating: Moderate
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.
Cal-IPC Newsletter Articles
- Weed biological control agents approved for California. Pitcairn, Michael J.; Smith, Lincoln; Moran, Patrick. Vol 22, Issue 1
- Taking to the air to locate, prioritize and treat effectively. Burger, Jutta C.. Vol 21, Issue 2
- Tackling invasive plants on California Sept. of Fish & Game lands. O'Rourke, Brianne; Horenstein, Julie. Vol 17, Issue 1
- Shasta County citizens take on weeds. Dozier, Melissa. Vol 14, Issue 4
- More about Italian thistle. Massera, Jack. Vol 09, Issue 2
- Italian thistles: an ominous threat. Cowan, B.. Vol 08, Issue 1
- Lessons from the front: Taking stock to avoid surprises. Kelly, Mike. Vol 05, Issue 1
- California Exotic Pest Plant Council draft list exotic plants of greatest concern October 1993. CalEPPC. Vol 01, Issue 4
Cal-IPC Symposium Presentations
- Archbald, G. (1998). Mechanical control methods: beyond weed bashing. California Exotic Pest Plant Council Symposium '98. Ontario, CA.
- Boyd, D. (1997). Eucapyptus removal on Angel Island. California Exotic Pest Plant Council Symposium '97. Concord, CA.
- Briscoe, E. and T. Anderson (2000). War on weeds - invasive weed education and outreach program. California Exotic Pest Plant Council Symposium 2000. Concord, CA.
- Clines, J., J. DiTomaso, et al. (2004). Fire working group. California Invasive Plant Council Symposium 2004. Ventura, CA.
- Guerriero, A. (2002). Monitoring Carduus pycnocephalus (Italian thistle) on grasslands in coastal central California. California Exotic Pest Plant Council Symposium 2002. Sacramento, CA.
- Pirosko, C. and S. Schoenig (2004). Forbs working group. California Invasive Plant Council Symposium 2004. Ventura, CA.
- Pitcairn, M. J. and D. M. Woods (1998). Control methods: Biological control. California Exotic Pest Plant Council Symposium '98. Ontario, CA.
- Pitcairn, M. J. and D. M. Woods (1998). Control methods: biological control. California Exotic Pest Plant Council Symposium 1998. Ontario, CA.
Other Carduus pycnocephalus Information
- CalPhotos - Images of plants taken mostly in California.
- CalFlora - Distribution information based on submitted observations and herbarium specimens.
- CalWeedMapper - Distribution information with ability to determine regional priorities.
- Jepson Online Interchange for California Flora - Information on taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
- CDFA - California official noxious weeds.
- USDA PLANTS Database - Federal database with information on identification and distribution, and links to websites in individual states.
- Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.