California Agaricus
Agaricus californicus · Family Agaricaceae · Updated October 2026
185US records
1states
Novbusiest month
185 US records since 1895 (106 in the last 10 years)
Last seen Jan 4, 2026 (about 10 months ago) near El Cerrito, Contra Costa County, CA, photographed by an iNaturalist user, with the ID agreed on by other iNaturalist users (research grade). Most US records come from California, and the busiest months are Nov, Dec and Jan. (Data as of October 26, 2026; records can lag by weeks.)
⚠ Never eat a wild mushroom based on this site. We show where fungi have been recorded, nothing more. We never say any mushroom is edible or safe, and you shouldn't decide that from any website, app or photo. Many deadly mushrooms look like harmless ones. If someone may have eaten a wild mushroom, call Poison Control at 1-800-222-1222 right away.
Lookalike warning. Many mushrooms, including deadly ones, closely resemble each other, and the only reliable identification comes from an expert looking at the actual specimen (often with spore prints or microscopy). Never use a name, photo or record count on this page to decide what something is.
When it's recorded
Records by month, all years. Busiest: Nov, Dec, Jan.
Where it's recorded
| State | Records | Latest sighting |
|---|---|---|
| California | 185 | Jan 4, 2026 |
Top counties
- San Francisco County, CA (57) · latest Jan 5, 2025
- San Mateo County, CA (25) · latest Dec 2, 2025
- Los Angeles County, CA (21) · latest Dec 25, 2025
- Marin County, CA (14) · latest Sep 28, 2024
- Alameda County, CA (13) · latest Nov 7, 2025
- Santa Cruz County, CA (8) · latest Jan 3, 2026
- Santa Clara County, CA (7) · latest Apr 18, 2020
- Monterey County, CA (6) · latest Nov 30, 2025
- Orange County, CA (6) · latest Apr 13, 2020
- Santa Barbara County, CA (5) · latest Jan 10, 2016
More on this species from GBIF.
Bring along
🍄
Regional mushroom field guideSee on Amazon🍄
Folding mushroom knife with brushSee on Amazon🍄
Wicker foraging basketSee on Amazon🍄
10x hand lens / loupeSee on Amazon🍄
Spore print paperSee on AmazonAs an Amazon Associate we earn from qualifying purchases.