Centaurea jacea ssp. pratensis

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.

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.
  • 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

None for this species.

Cal-IPC News Articles