Mountain Polypore
Bondarzewia mesenterica · Family Bondarzewiaceae · Updated October 2026
66US records
10states
Sepbusiest month
66 US records since 1885 (2 in the last 10 years)
Last seen Aug 2, 2020 (about 6 years ago) near Brook Forest, Jefferson County, CO, a preserved specimen in Denver Botanic Gardens, Sam Mitchel Herbarium of Fungi. Most US records come from Washington, California and Ohio, and the busiest months are Sep, Oct and Aug. (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: Sep, Oct, Aug.
Where it's recorded
Top counties
- Franklin County, OH (10) · latest Oct 20, 1902
- Chester County, PA (8) · latest 1885-09
- Pierce County, WA (6) · latest Oct 9, 2014
- Bonner County, ID (4) · latest Sep 30, 1972
- Jefferson County, WA (4) · latest Sep 11, 1997
- Butte County, CA (3) · latest Nov 5, 1932
- Clallam County, WA (3) · latest Aug 22, 2000
- Snohomish County, WA (3) · latest Aug 16, 1995
- Alpine County, CA (2) · latest Sep 21, 1980
- Siskiyou County, CA (2) · latest Nov 15, 2012
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.