California Invasive Plant Council

Cynara cardunculus

Common names: artichoke thistle; cardoon; wild artichoke

Cynara cardunculus (artichoke thistle) is a large perennial thistle (family Asteraceae) from the Mediterranean region found below 500 m elevations throughout California, except in the Great Basin and Desert Regions. Artichoke thistle prefers disturbed open sites, including grassland, chaparral, coastal scrub, and riparian areas. This thistle is closely related to cultivated artichokes (Cynara scolymus), and the two species hybridize frequently. Artichoke thistle is also sometimes grown as an ornamental plant, and is available commercially. It reproduces by seed and sometimes by resprouting from root fragments. Rosettes can reach a diameter of well over one meter; leaves are large, spiny, and sharply lobed, and plants typically flower in May and June.  When attempting control by mechanical removal, most of the plant’s large taproot must be removed to avoid resprouting.

Cal-IPC Rating: Moderate?

Explanation of Cal-IPC ratings

• High – These species have severe ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment. Most are widely distributed ecologically.
• Moderate – These species have substantial and apparent-but generally not severe-ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread.
• Limited – These species are invasive but their ecological impacts are minor on a statewide level or there was not enough information to justify a higher score. Their reproductive biology and other attributes result in low to moderate rates of invasiveness. Ecological amplitude and distribution are generally limited, but these species may be locally persistent and problematic.
• Alert – An Alert is listed on species with High or Moderate impacts that have limited distribution in California, but may have the potential to spread much further.
• Watch – These species have been assessed as posing a high risk of becoming invasive in the future in California.

CDFA Rating: -*?

Explanation of CDFA ratings

• A – A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment.
• B – A pest of known economic or environmental detriment and, if present in California, it is of limited distribution.
• C – A pest of known economic or environmental detriment and, if present in California, it is usually widespread.
• D – An organism known to be of little or no economic or environmental detriment, to have an extremely low likelihood of weediness, or is known to be a parasite or predator.
• Q – An organism or disorder suspected to be of economic or environmental detriment, but whose status is uncertain because of incomplete identification or inadequate information.
• * – An asterisk next to the rating indicates that a plant is included in the CCR Section 4500 list of California State Noxious Weeds.
• -* – This plant is included in the CCR Section 4500 list of California State Noxious Weeds, but is otherwise not rated.

More details

Assessment(s)

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.

Species ID Card

Invasive Species ID Card - To support field identification of early detection species, Cal-IPC has designed a set of Species ID cards that can be downloaded, printed double-sided, and trimmed to size.

Weed Management Notes

• Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.

Cal-IPC Newsletter Articles

• Are we making progress? A bird's-eye view of change in invasive plant cover in central-coastal Orange County. Burger, Jutta C.. Vol 27, Issue 2
• Tracking eradication progress . Guise, Vince. Vol 21, Issue 3
• Taking to the air to locate, prioritize and treat effectively. Burger, Jutta C.. Vol 21, Issue 2
• “Conservation Across Borders” in San Jose. Cal-IPC. Vol 14, Issue 2
• Invasive plants research at UC Riverside. Holt, Jodie S.. Vol 13, Issue 2
• Education: Wildland weed tours and talks. Kelly, Mike. Vol 08, Issue 1
• Roundup of Arundo projects reveals commitment, strategic weakness. Kelly, Mike. Vol 07, Issue 2
• Richmond weed abatement ordinance. . Vol 07, Issue 1
• Starr Ranch Sanctuary artichoke conference. Kelly, Mike. Vol 06, Issue 3
• Legendary stewardship award. Goode, Suzanne. Vol 06, Issue 2
• Killing the beast: A cooperative approach for control of Arundo donax in the Santa Ana River watershed. Stein, Eric D.; Vartanian, Valerie. Vol 05, Issue 3
• Lessons from the front: Taking stock to avoid surprises. Kelly, Mike. Vol 05, Issue 1
• Exotic pest plants of greatest ecological concern in California September 1994. Cal-IPC. Vol 02, Issue 4
• The ecology and management of the wild artichoke Cynara cardunculus. Pepper, Alan; Kelly, Mike. Vol 02, Issue 1
• California Exotic Pest Plant Council draft list exotic plants of greatest concern October 1993. CalEPPC. Vol 01, Issue 4
• Control of exotic plants in an herbaceous understory. Perala, Christine; Hoover, Doris A.; Parra-Szijj, E.A.. Vol 01, Issue 3

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

• Evolution of an invasive plant control program – adoption of early detection and rapid response. Mitrovich, Milan (2018)
• Effects of an exotic herbaceous perennial, Cynara cardunculus, on small mammals and songbirds. DeSimone, Sandra A.; Gibson, Scott E. (2010)
• Artichoke thistle (Cynara cardunculus) control efforts and community recovery in historic southern California rangeland. Royall, Margaret; Murdock, Michelle; Suding, Katharine; Smith, Trish (2007)
• Non-chemical Exotic Control in Coastal Sage Scrub Restoration at an Audubon Preserve. DeSimone, Sandra (2007)
• Ecological approaches for weed management. Holt, Jodie S. (2006)
• Forbs working group. Pirosko, Carri; Schoenig, Steve (2004)
• Patterns of seedling establishment in artichoke thistle, Cynara cardunculus. Marushia, Robin; Holt, Jodie S. (2003)
• Prediction of Cynara cardunculus seedling development using a degree-day approach. White, Virginia A.; Holt, Jodie S. (2003)
• Effect of competition on artichoke thistle, Cynara cardunculus. White, Virginia A.; Holt, Jodie S. (2002)
• Using Transline* herbicide to control invasive plants. Carrithers, Vanelle F. (1997)
• Controlling Cynara cardunculus (artichoke thistle, cardoon, etc.). Kelly, Mile; Pepper, Alan (1996)
• An artichoke thistle success story. Tidwell, Bill (1994)

Other Cynara cardunculus Information

• CalPhotos - Images of plants taken mostly in California.
• Calflora - Distribution map and records of this species in California.
• CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
• EDDMapS - Distribution of this species in North America.
• Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
• USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.

Additional photos