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Distribution by County   3023    
Equisetum hyemale  L.  ssp. affine  (Engelm.) Calder & Roy L. Taylor
Giant scouring rush
Equisetum hyemale ssp. affine is a fern that is native to California, and also found elsewhere in North America and beyond.
Record Count by County

Alameda: 17 Lake: 5 Placer: 9 Shasta: 18
Alpine: 5 Lassen: 3 Plumas: 15 Sierra: 3
Amador: 2 Los Angeles: 48 Riverside: 10 Siskiyou: 13
Butte: 35 Madera: 2 Sacramento: 33 Solano: 12
Colusa: 2 Marin: 29 San Bernardino: 22 Sonoma: 27
Contra Costa: 5 Mariposa: 13 San Diego: 18 Sutter: 1
Del Norte: 11 Mendocino: 26 San Francisco: 12 Tehama: 12
El Dorado: 15 Modoc: 5 San Joaquin: 1 Trinity: 21
Fresno: 25 Mono: 4 San Luis Obispo: 12 Tulare: 17
Glenn: 2 Monterey: 15 San Mateo: 18 Tuolumne: 1
Humboldt: 18 Napa: 3 Santa Barbara: 33 Ventura: 16
Imperial: 2 Nevada: 3 Santa Clara: 5 Yolo: 1
Inyo: 8 Orange: 16 Santa Cruz: 17 Yuba: 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: 08/18/2026).