Calflora, a 501c3 non-profit
Distribution by County   117    
Ageratina adenophora  (Spreng.) R. M. King & H. Rob.
Sticky snakeroot, Thoroughwort
Ageratina adenophora is a perennial herb that is not native to California.
Cal-IPC rating: moderate
Record Count by County

Alameda: 46 Marin: 5294 San Bernardino: 16 Santa Barbara: 130
Contra Costa: 26 Mendocino: 1 San Diego: 58 Santa Clara: 5
Fresno: 1 Monterey: 84 San Francisco: 19 Santa Cruz: 106
Kern: 1 Orange: 300 San Luis Obispo: 32 Ventura: 5
Los Angeles: 961 Riverside: 8 San Mateo: 3 Yolo: 1

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: 04/22/2026).