Inocybe decemgibbosa
Family Inocybaceae · Updated October 2026
36US records
8states
Sepbusiest month
36 US records since 1946 (3 in the last 10 years)
Last seen Aug 11, 2021 (about 5 years ago) near Lake Placid, Essex County, NY, a preserved specimen in University of Tennessee Fungal Herbarium. Most US records come from Washington, Michigan and North Carolina, and the busiest months are Sep, Aug and Jul. (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.
☠ Dangerous genus. The genus Inocybe includes fibercaps containing muscarine. Mushrooms in this group have caused serious or fatal poisonings.
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: Sep, Aug, Jul.
Where it's recorded
| State | Records | Latest sighting |
|---|---|---|
| Washington | 26 | Aug 25, 2002 |
| Michigan | 2 | Sep 28, 2015 |
| North Carolina | 2 | Jul 11, 2020 |
| Idaho | 2 | Sep 16, 1977 |
| New Jersey | 1 | Oct 22, 1995 |
| New York | 1 | Aug 11, 2021 |
| Massachusetts | 1 | – |
| Oregon | 1 | Oct 13, 1946 |
Top counties
- Pierce County, WA (18) · latest 1969-07
- King County, WA (3) · latest Aug 25, 2002
- San Juan County, WA (3) · latest Jun 18, 1960
- Mercer County, NJ (1) · latest Oct 22, 1995
- Houghton County, MI (1) · latest Sep 28, 2015
- Haywood County, NC (1) · latest Jul 11, 2020
- Swain County, NC (1) · latest Jul 7, 2019
- Essex County, NY (1) · latest Aug 11, 2021
- Worcester County, MA (1)
- Kitsap County, WA (1) · latest Jun 29, 1999
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.