Calflora, a 501c3 non-profit
Distribution by County   7641    
Sium suave  Walter
Hemlock water parsnip,   Hemlock waterparsnip
Sium suave is a perennial herb that is native to California, and also found elsewhere in North America and beyond.
Record Count by County

Contra Costa: 5 Mariposa: 2 San Joaquin: 3 Tehama: 2
El Dorado: 2 Mendocino: 6 Santa Barbara: 1 Trinity: 3
Fresno: 1 Modoc: 2 Santa Clara: 1 Tulare: 1
Inyo: 1 Mono: 4 Shasta: 1
Lassen: 4 Napa: 2 Siskiyou: 4
Madera: 2 Plumas: 14 Solano: 9

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: 01/19/2026).