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Mushrooms in San Mateo County, California
Updated October 2026 · from open GBIF records
5,278mushroom records
671species recorded
Decbusiest month
5,278 records since 1894 (3,511 in the last 10 years)
Fruiting now
Based on past sightings (mostly since 2011; all years where recent records are few), not a forecast. Weather and place matter a lot, and a listing here says nothing about whether a mushroom is safe.
Usually recorded in January here:
Fly Agaric Amanita muscaria92 January records since 2011
California Jack O' Lantern Omphalotus olivascens67 January records since 2011- Birch Mazegill, Gilled Polypore Lenzites betulinus31 January records since 2011
Yellow Fieldcap Bolbitius titubans25 January records since 2011
Questionable Stropharia Stropharia ambigua23 January records since 2011
Mock Oyster Mushroom Phyllotopsis nidulans22 January records since 2011
Turkeytail Trametes versicolor22 January records since 2011
Golden Milk Cap Lactarius alnicola22 January records since 2011
Big Sheath Mushroom Volvopluteus gloiocephalus22 January records since 2011
Western Amethyst Laccaria Laccaria amethysteo-occidentalis21 January records since 2011
Sulphur Tuft Hypholoma fasciculare21 January records since 2011
Chip Cherries Leratiomyces ceres20 January records since 2011
Usually recorded in February here:
- Turkeytail Trametes versicolor26 February records since 2011
Hairy Curtain Crust Stereum hirsutum23 February records since 2011- California Jack O' Lantern Omphalotus olivascens19 February records since 2011
- Yellow Fieldcap Bolbitius titubans16 February records since 2011
- Birch Mazegill, Gilled Polypore Lenzites betulinus16 February records since 2011
Rosy Conk Rhodofomes cajanderi14 February records since 2011
Mulch Maids Leratiomyces percevalii14 February records since 2011- Mock Oyster Mushroom Phyllotopsis nidulans12 February records since 2011
Northern Red Belt Fomitopsis mounceae10 February records since 2011- Sulphur Tuft Hypholoma fasciculare10 February records since 2011
Common Porecrust, Split Gill Fungus Schizophyllum commune10 February records since 2011
Galactic Milk Cap Lactarius xanthogalactus9 February records since 2011
Usually recorded in March here:
Bittersweet Orange Ringless Amanita Amanita velosa22 March records since 2011- Mulch Maids Leratiomyces percevalii14 March records since 2011
- Turkeytail Trametes versicolor10 March records since 2011
- Hairy Curtain Crust Stereum hirsutum8 March records since 2011
- Yellow Fieldcap Bolbitius titubans8 March records since 2011
- California Jack O' Lantern Omphalotus olivascens8 March records since 2011
Glistening Ink-Cap Coprinellus micaceus6 March records since 2011- Fly Agaric Amanita muscaria5 March records since 2011
- Common Porecrust, Split Gill Fungus Schizophyllum commune5 March records since 2011
- Mock Oyster Mushroom Phyllotopsis nidulans4 March records since 2011
Pale Brittlestem Candolleomyces candolleanus4 March records since 2011
Lawyer's Wig Coprinus comatus4 March records since 2011
Usually recorded in April here:
- Bittersweet Orange Ringless Amanita Amanita velosa12 April records since 2011
- Turkeytail Trametes versicolor9 April records since 2011
- Fly Agaric Amanita muscaria7 April records since 2011
- Northern Red Belt Fomitopsis mounceae6 April records since 2011
- Pale Brittlestem Candolleomyces candolleanus6 April records since 2011
- Common Porecrust, Split Gill Fungus Schizophyllum commune6 April records since 2011
- Hairy Curtain Crust Stereum hirsutum5 April records since 2011
Red Cage Clathrus ruber5 April records since 2011
Petticoat Mottlegill Panaeolus papilionaceus5 April records since 2011- Lawyer's Wig Coprinus comatus4 April records since 2011
- Birch Mazegill, Gilled Polypore Lenzites betulinus4 April records since 2011
- Questionable Stropharia Stropharia ambigua4 April records since 2011
Usually recorded in May here:
- Common Porecrust, Split Gill Fungus Schizophyllum commune7 May records since 2011
- Turkeytail Trametes versicolor5 May records since 2011
Netted Fieldcap Bolbitius reticulatus4 May records since 2011
Artist's Conk Ganoderma brownii4 May records since 2011- Red Cage Clathrus ruber4 May records since 2011
Cryptic Globe Fungus Cryptoporus volvatus4 May records since 2011- Hairy Curtain Crust Stereum hirsutum3 May records since 2011
Salty Mushroom Agaricus bernardii2 May records since 2011- Fly Agaric Amanita muscaria2 May records since 2011
Redhead Russula Russula rhodocephala2 May records since 2011- Mock Oyster Mushroom Phyllotopsis nidulans2 May records since 2011
Common Puffball Lycoperdon perlatum2 May records since 2011
Usually recorded in June here:
- Northern Red Belt Fomitopsis mounceae8 June records since 2011
- Turkeytail Trametes versicolor8 June records since 2011
Prince Agaricus augustus5 June records since 2011
Frosty Bonnet Mycena tenerrima4 June records since 2011- Clathrus archeri3 June records since 2011
- Rosy Conk Rhodofomes cajanderi3 June records since 2011
- Birch Mazegill, Gilled Polypore Lenzites betulinus3 June records since 2011
- Artist's Conk Ganoderma brownii3 June records since 2011
Common Fieldcap Agrocybe pediades2 June records since 2011- Cryptic Globe Fungus Cryptoporus volvatus2 June records since 2011
Usually recorded in July here:
- Turkeytail Trametes versicolor7 July records since 2011
- Prince Agaricus augustus6 July records since 2011
- Birch Mazegill, Gilled Polypore Lenzites betulinus4 July records since 2011
Pine Bracket Porodaedalea pini4 July records since 2011- Northern Red Belt Fomitopsis mounceae2 July records since 2011
- Pale Brittlestem Candolleomyces candolleanus2 July records since 2011
Plantpot Dapperling Leucocoprinus birnbaumii2 July records since 2011
Brown Parasol Chlorophyllum brunneum2 July records since 2011- Common Fieldcap Agrocybe pediades2 July records since 2011
California Agaricus Agaricus californicus2 July records since 2011
Usually recorded in August here:
- Turkeytail Trametes versicolor4 August records since 2011
Brown Hay Cap Panaeolina foenisecii3 August records since 2011
Death Cap Amanita phalloides2 August records since 2011- Glistening Ink-Cap Coprinellus micaceus2 August records since 2011
- Pale Brittlestem Candolleomyces candolleanus2 August records since 2011
Milky Conecap Conocybe apala2 August records since 2011
Usually recorded in September here:
- Turkeytail Trametes versicolor6 September records since 2011
Western Chicken-Of-The-Woods Laetiporus gilbertsonii6 September records since 2011- Artist's Conk Ganoderma brownii3 September records since 2011
- Northern Red Belt Fomitopsis mounceae2 September records since 2011
- Birch Mazegill, Gilled Polypore Lenzites betulinus2 September records since 2011
Brown Cubical Rot Laetiporus conifericola2 September records since 2011- Hairy Curtain Crust Stereum hirsutum2 September records since 2011
Usually recorded in October here:
Pisolithus tinctorius9 October records since 2011- Death Cap Amanita phalloides8 October records since 2011
- Western Chicken-Of-The-Woods Laetiporus gilbertsonii6 October records since 2011
- Turkeytail Trametes versicolor6 October records since 2011
- Birch Mazegill, Gilled Polypore Lenzites betulinus5 October records since 2011
Ballen's American Caesar Amanita calyptroderma4 October records since 2011
California Golden Chanterelle Cantharellus californicus4 October records since 2011- Artist's Conk Ganoderma brownii3 October records since 2011
Pungent Slippery Jack Suillus pungens3 October records since 2011
Yellow Stainer Agaricus xanthodermus3 October records since 2011- Common Porecrust, Split Gill Fungus Schizophyllum commune2 October records since 2011
- Hairy Curtain Crust Stereum hirsutum2 October records since 2011
Usually recorded in November here:
- California Jack O' Lantern Omphalotus olivascens26 November records since 2011
- Death Cap Amanita phalloides21 November records since 2011
- Sulphur Tuft Hypholoma fasciculare16 November records since 2011
- Ballen's American Caesar Amanita calyptroderma13 November records since 2011
- Turkeytail Trametes versicolor8 November records since 2011
- Northern Red Belt Fomitopsis mounceae7 November records since 2011
- Golden Milk Cap Lactarius alnicola7 November records since 2011
- Questionable Stropharia Stropharia ambigua7 November records since 2011
- Western Chicken-Of-The-Woods Laetiporus gilbertsonii6 November records since 2011
Liver Bolete Suillellus amygdalinus6 November records since 2011
Redwood Rooter Caulorhiza umbonata6 November records since 2011
Oak-Leaf Pinwheel Collybiopsis quercophila6 November records since 2011
Usually recorded in December here:
- Fly Agaric Amanita muscaria80 December records since 2011
- California Jack O' Lantern Omphalotus olivascens31 December records since 2011
- Hairy Curtain Crust Stereum hirsutum26 December records since 2011
- Death Cap Amanita phalloides26 December records since 2011
- Sulphur Tuft Hypholoma fasciculare25 December records since 2011
Honey Fungus Armillaria mellea18 December records since 2011- Chip Cherries Leratiomyces ceres16 December records since 2011
- Yellow Fieldcap Bolbitius titubans16 December records since 2011
- Turkeytail Trametes versicolor16 December records since 2011
Cat's Tongue Pseudohydnum gelatinosum15 December records since 2011- Pungent Slippery Jack Suillus pungens14 December records since 2011
Wood Blewit Lepista nuda13 December records since 2011
⚠ 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.
Most-recorded species
| # | Species | Records |
|---|---|---|
| 1 | 201 | |
| 2 | 169 | |
| 3 | 131 | |
| 4 | 103 | |
| 5 | 89 | |
| 6 | 89 | |
| 7 | 81 | |
| 8 | 81 | |
| 9 | 60 | |
| 10 | 59 | |
| 11 | 54 | |
| 12 | 54 | |
| 13 | 53 | |
| 14 | 52 | |
| 15 | 51 |
Being on this list doesn't mean a mushroom is common, easy to identify or safe. It only means it has been recorded here often.
Best months to look
Records by month, all years. Busiest: Dec, Jan, Feb.
Sightings map
● Each dot is a place with at least one record (rounded to about 1 km). Locations can be approximate, and many are on private land. Numbered blue circles are recent sightings, shown only to a general area of about 10 km.
Recent sightings
The 9 most recent dated records in this county, newest first. Data as of October 26, 2026. Records can take weeks or more to reach GBIF, so the newest finds may not show yet. Places are given only as a public park or forest (from the USGS Protected Areas Database) or the nearest town, and the numbered circles on the map cover a general area, not an exact spot.
- 1Sep 21, 2026Cryptic Globe Fungus Cryptoporus volvatusin Golden Gate National Recreation Area, CA · iNaturalist photo, research grade · original record
- 2Sep 20, 2026Western Chicken-Of-The-Woods Laetiporus gilbertsoniinear El Granada, CA · iNaturalist photo, research grade · original record
- 3Sep 20, 2026Western Chicken-Of-The-Woods Laetiporus gilbertsoniinear San Mateo, CA · iNaturalist photo, research grade · original record
- 4Aug 10, 2026Turkeytail Trametes versicolorin Windy Hill Open Space Preserve, CA · iNaturalist photo, research grade · original record
- 5
Aug 7, 2026Bearded Tooth Hericium erinaceusnear Loma Mar, CA · iNaturalist photo, research grade · original record - 6Aug 2, 2026Common Porecrust, Split Gill Fungus Schizophyllum communein Crestview Park, CA · iNaturalist photo, research grade · original record
- 7
Jul 29, 2026False Parasol Chlorophyllum molybditesnear Palo Alto, CA (location blurred by the observer) · iNaturalist photo, research grade · original record - 8Jul 29, 2026Prince Agaricus augustusnear Pacifica, CA · iNaturalist photo, research grade · original record
- 9
Jul 11, 2026Floury Oyster Hohenbuehelia petaloidesnear Redwood City, CA · iNaturalist photo, research grade · original record
Many sightings are on private land. Always get the landowner's permission, and follow the rules of parks and forests, which often limit or ban collecting.
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.
How we built this page
5,278 records of mushrooms, shelf fungi and polypores (class Agaricomycetes) that fall inside this county's Census boundary. Licenses: 2,819 CC0 and 2,459 CC BY 4.0. See about the data for the full citation.