Calflora, a 501c3 non-profit
Distribution by County   1505    
Carduus tenuiflorus  Curtis
Italian thistle,   Slender flowered thistle,   Winged plumeless thistle
Carduus tenuiflorus is an annual herb that is not native to California.
Cal-IPC rating: limited
Record Count by County

Alameda: 55 Lake: 25 Sacramento: 25 Sonoma: 47
Amador: 6 Los Angeles: 31 San Benito: 46 Stanislaus: 29
Butte: 11 Madera: 22 San Bernardino: 9 Sutter: 8
Calaveras: 14 Marin: 28 San Diego: 81 Tehama: 2
Colusa: 8 Mariposa: 19 San Francisco: 8 Trinity: 6
Contra Costa: 25 Mendocino: 80 San Joaquin: 33 Tulare: 16
Del Norte: 9 Merced: 48 San Luis Obispo: 43 Tuolumne: 17
El Dorado: 7 Monterey: 122 San Mateo: 55 Ventura: 35
Fresno: 23 Napa: 14 Santa Barbara: 61 Yolo: 17
Glenn: 2 Nevada: 9 Santa Clara: 79 Yuba: 10
Humboldt: 76 Orange: 15 Santa Cruz: 15
Kern: 14 Placer: 8 Siskiyou: 6
Kings: 2 Riverside: 9 Solano: 22

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]. 2024. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 11/21/2024).