California Invasive Plant Council

Centaurea stoebe ssp. micranthos

Synonyms: Centaurea maculosa; Centaurea biebersteinii, Centaurea stoebe ssp. stoebe and ssp. maculosa

Common names: spotted knapweed

Centaurea maculosa (spotted knapweed) is a biennial to short-lived perennial (family Asteraceae). It can be found in disturbed open sites, grasslands, overgrazed rangelands, roadsides and logged areas. It crowds out native species and forage for livestock, and can invade undisturbed native bunchgrass stands. An individual plant may produce as many as 40,000 seeds.

Jepson Manual, 2nd Edition: Centaurea stoebe subsp. micranthos

Cal-IPC Rating: High

CDFA Rating: A

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.

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

• Celebrating park stewards. Cal-IPC. Vol 24, Issue 2
• Weed biological control agents approved for California. Pitcairn, Michael J.; Smith, Lincoln; Moran, Patrick. Vol 22, Issue 1
• Jepson Manual 2nd ed. invasive plant name changes. Brusati, Elizabeth. Vol 20, Issue 2
• Prioritizing Regional Response to Invasive Plants in the Sierra Nevada. Brusati, Elizabeth; Morawitz, Dana; Powell, Cynthia. Vol 19, Issue 2
• Wildland Weed News. editor. Vol 17, Issue 2
• Tackling invasive plants on California Sept. of Fish & Game lands. O'Rourke, Brianne; Horenstein, Julie. Vol 17, Issue 1
• Fighting weeds in the Tahoe basin. Donaldson, Sue. Vol 11, Issue 2

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.

• Floodplains restoration post-infestation on the North Fork Salmon River. Malone-Persha, Deja (2020)
• Using detection dogs to enhance invasive plant management strategies. Hurt, Aimee (2020)

Other Centaurea stoebe ssp. micranthos Information

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