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Distribution by County   13621    
Rhaponticum repens  (L.) Hidalgo
Russian knapweed
Rhaponticum repens is a perennial herb that is not native to California.
Cal-IPC rating: moderate
Record Count by County

Alameda: 20 Lake: 2 Plumas: 14 Siskiyou: 32
Alpine: 5 Lassen: 68 Riverside: 40 Solano: 34
Amador: 5 Los Angeles: 51 Sacramento: 14 Sonoma: 3
Butte: 4 Madera: 5 San Benito: 25 Stanislaus: 2
Colusa: 4 Marin: 28 San Bernardino: 55 Sutter: 89
Contra Costa: 26 Merced: 7 San Diego: 18 Tehama: 3
El Dorado: 10 Modoc: 15 San Joaquin: 11 Tulare: 34
Fresno: 51 Mono: 15 San Luis Obispo: 47 Tuolumne: 2
Glenn: 12 Monterey: 20 Santa Barbara: 34 Ventura: 131
Imperial: 4 Napa: 8 Santa Clara: 20 Yolo: 50
Inyo: 18 Nevada: 39 Santa Cruz: 7 Yuba: 1
Kern: 50 Orange: 34 Shasta: 7
Kings: 42 Placer: 31 Sierra: 5

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. [web application]. 2026. The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 03/12/2026).