Carduus tenuiflorus

Carduus tenuiflorus_slenderflower thistle_JM DiTomaso_cropped
Photo: Joseph DiTomaso

Common names: slenderflower thistle; Italian thistle; multiheaded thistle; seaside thistle; shore thistle; winged plumeless thistle

Carduus tenuiflorus (slender flowered thistle) is a tall annual or biennial (family Asteraceae) located along the California coast and in the Central Valley and Sierra foothill grasslands. It is similar in appearance and habitat to Italian thistle (Carduus pycnocephalus), but is less widely distributed.

Cal-IPC Rating: Limited

CDFA Rating: C*

Cal-IPC Assessment

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.

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

There are no newsletter articles associated with this species yet.

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.

There are no Symposium presentations associated with this species yet.

Other Carduus tenuiflorus Information

  • CalPhotos - Images of plants taken mostly in California.
  • Calflora - See the distribution of this species on Calflora's map of California.
  • 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.
  • EDDMapS - North American distribution based on Early Detection and Distribution Mapping System.