Yellow Stainer
Agaricus xanthodermus · Family Agaricaceae · Updated October 2026
470US records
21states
Novbusiest month
470 US records since 1905 (377 in the last 10 years)
Last seen Sep 14, 2026 (about 6 weeks ago) near Corvallis, Benton County, OR, photographed by an iNaturalist user, with the ID agreed on by other iNaturalist users (research grade). Most US records come from California, Oregon and Colorado, and the busiest months are Nov, Dec and Oct. (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, Oct.
Where it's recorded
Top counties
- San Francisco County, CA (46) · latest Apr 15, 2026
- Marin County, CA (44) · latest May 6, 2026
- San Mateo County, CA (35) · latest Jan 24, 2026
- Alameda County, CA (32) · latest Dec 6, 2025
- Santa Cruz County, CA (30) · latest Feb 5, 2026
- Denver County, CO (28) · latest Sep 16, 2021
- Lane County, OR (23) · latest Nov 24, 2024
- Benton County, OR (23) · latest Sep 14, 2026
- Los Angeles County, CA (21) · latest Dec 1, 2025
- Santa Clara County, CA (20) · latest Feb 3, 2026
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.