Synonyms: Acroptilon repens, Centaurea repens
Common names: Russian knapweed, hardheads, creeping knapweed, mountain bluet, Turkestan thistle
Rhaponticum repens (Russian knapweed) is a perennial forb (family Asteraceae) found in isolated patches throughout California. It may have allelopathic properties. This plant is toxic to horses and crowds out native species.Cal-IPC Rating: Moderate?
CDFA Rating: B*?
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
- Prioritizing Regional Response to Invasive Plants in the Sierra Nevada. Brusati, Elizabeth; Morawitz, Dana; Powell, Cynthia. Vol 19, Issue 2
- 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.
- Biological control agents of weeds in California: Overview of rearing, releases, and monitoring by the CDFA Biological Control Program. Moran, Patrick (2023)
- Preventing weed spread via contaminated hay and straw. Clines, Joanna (2005)
- Getting the job done: Working within the regulatory environment at Lake Tahoe to manage weeds. Donaldson, Susan; West, Wendy; Taylor, Kirk (2003)
- How the west was lost: Reconstructing the invasion dynamics of yellow star-thistle and other plant invaders of western rangelands and natural areas. Gerlach, John D. (1997)
Other Rhaponticum repens Information
- Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.
- 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.