Calflora, a 501c3 non-profit
Distribution by County   4552    
Lactuca virosa  L.
Bitter lettuce,   Poison wild lettuce
Lactuca virosa is a perennial herb that is not native to California.
Record Count by County

Alameda: 32 Madera: 1 Nevada: 1 Siskiyou: 2
Butte: 1 Marin: 11 San Diego: 2 Sonoma: 1
Contra Costa: 27 Mariposa: 38 San Luis Obispo: 1 Tehama: 2
El Dorado: 2 Mendocino: 4 San Mateo: 57 Trinity: 3
Humboldt: 5 Mono: 3 Santa Clara: 9 Tuolumne: 4
Kern: 1 Monterey: 5 Santa Cruz: 10 Yuba: 2
Los Angeles: 1 Napa: 1 Shasta: 2

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]. 2025. The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 05/16/2025).