Centaurea jacea ssp. pratensis

Photo: Joseph DiTomaso

Synonyms: Centaurea debeauxii Gren. & Godr., Centaurea x pratensis; Centaurea jacea L. x Centaurea nigra L.

Common names: meadow knapweed

Centaurea jacea ssp. pratensis (=Centaurea debeauxii or C. jacea x C. nigra or C. x pratensis) (meadow knapweed) is a bushy perennial (family Asteraceae) found in a small number of disturbed areas in Siskiyou, Del Norte, and Humboldt Counties in northwestern California. Meadow knapweed reproduces by seed and via shoots from the parent plant, and is known to resprout from root fragments after cultivation. The seeds can also be spread by irrigation systems and vehicles. Meadow knapweed spreads very rapidly and is listed as a noxious weed in several western states as well as California.

Cal-IPC Rating: Moderate — Alert?

CDFA Rating: -*?


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

No Weed RIC Management Notes are available for this species. Check for information on other species in the genus on the Weed RIC site.

Cal-IPC Newsletter Articles

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.

Other Centaurea jacea ssp. pratensis Information

  • CalPhotos - Images of plants taken mostly in California.
  • Calflora - Distribution map and records of this species in California.
  • 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

    Centaurea jacea_flower heads_KeirMorse
    Centaurea jacea ssp. pratensis (meadow knapweed) flower heads. Photo: Keir Morse
    Centaurea jacea ssp. pratensis_growth habit_JeanPawek
    Centaurea jacea ssp. pratensis (meadow knapweed) growth habit. Photo: Jean Pawek