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Distribution by County   9902    
Equisetum telmateia  Ehrh.
Giant horsetail
Equisetum telmateia is a fern that is native to California, and also found elsewhere in North America and beyond.
Record Count by County

Alameda: 44 Los Angeles: 85 Sacramento: 2 Santa Cruz: 72
Butte: 14 Marin: 112 San Benito: 3 Shasta: 4
Calaveras: 1 Mendocino: 65 San Bernardino: 7 Siskiyou: 5
Colusa: 1 Mono: 3 San Diego: 32 Solano: 8
Contra Costa: 29 Monterey: 68 San Francisco: 24 Sonoma: 79
Del Norte: 15 Napa: 9 San Joaquin: 2 Tehama: 1
El Dorado: 2 Nevada: 2 San Luis Obispo: 86 Trinity: 12
Glenn: 2 Orange: 43 San Mateo: 145 Ventura: 17
Humboldt: 75 Plumas: 7 Santa Barbara: 76 Yolo: 1
Lake: 6 Riverside: 5 Santa Clara: 25 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: 08/11/2026).