Western Jumbo Gym
Gymnopilus ventricosus · Family Hymenogastraceae · Updated October 2026
267US records
6states
Decbusiest month
267 US records since 1901 (246 in the last 10 years)
Last seen Feb 19, 2026 (about 8 months ago) near Los Angeles, Los Angeles County, CA, photographed by an iNaturalist user, with the ID agreed on by other iNaturalist users (research grade). Most US records come from California, Oregon and Washington, and the busiest months are Dec, Jan and Nov. (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: Dec, Jan, Nov.
Where it's recorded
| State | Records | Latest sighting |
|---|---|---|
| California | 244 | Feb 19, 2026 |
| Oregon | 12 | Dec 4, 2025 |
| Washington | 5 | Oct 26, 2024 |
| Arizona | 3 | Sep 17, 2023 |
| New Mexico | 2 | Aug 24, 2019 |
| Colorado | 1 | Aug 11, 1974 |
Top counties
- San Mateo County, CA (40) · latest Feb 14, 2026
- San Francisco County, CA (35) · latest Dec 28, 2024
- Contra Costa County, CA (33) · latest Jan 4, 2026
- Alameda County, CA (22) · latest Dec 8, 2025
- Marin County, CA (19) · latest Nov 15, 2025
- Monterey County, CA (16) · latest Dec 26, 2024
- Santa Cruz County, CA (14) · latest Dec 12, 2025
- San Luis Obispo County, CA (14) · latest Jan 8, 2023
- Santa Clara County, CA (11) · latest Dec 20, 2025
- Humboldt County, CA (9) · latest Nov 4, 2024
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.