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Suillus fuscotomentosus Thiers & A.H. Sm.

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Scientific name
Suillus fuscotomentosus
Thiers & A.H. Sm.
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Assessment date
IUCN Red List Category
Siegel, N.
Dahlberg, A.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/198479142/198490249


Suillus fuscotomentosus is a common Suillus associated with three-needle pines in California, occurring in both coastal and Sierra Nevada forests. No decline has been noted, and the species is widespread, with threats to its host pines believed to be localized. Therefore, is is assessed as Least Concern (LC).

Taxonomic notes

Suillus fuscotomentosus was described from California, USA (Smith and Thiers 1964).

Geographic range

This species occurs in California, USA, in the central coast region north through the San Francisco Bay area, into the Coast Range, and throughout the Sierra Nevada foothills and mountains into the southern Cascade Range in Oregon.

Population and Trends

The population is widespread and appears to be stable overall. Some areas are under threat (particularly coastal Pinus radiata forests), but not at a scale large enough to substantially affect the overall population.

Population Trend: stable

Habitat and Ecology

It is ectomycorrhizal with three-needle pines; especially Monterey Pine (Pinus radiata) and Knobcone Pine (P. attenuata) in coastal subpopulations, and Ponderosa Pine (P. ponderosa) in Sierra Nevada subpopulations. It apparently does not occur with Jeffrey Pine (P. jeffreyi) in the eastern Sierra Nevada. Fruiting is in fall and winter, and it can be locally abundant.


Native stands of Pinus radiata are under threat from development, and a change in fire regime. Pinus ponderosa has suffered die-back from drought stress in the Sierra Nevada foothills. These threats are likely at a scale that has little affect on the overall population.

Conservation Actions

No specific conservation actions is needed with regards to this species, and no specific research is needed either.

Use and Trade

This species is edible, but rarely collected for food.

Source and Citation

Siegel, N. 2021. Suillus fuscotomentosus. The IUCN Red List of Threatened Species 2021: e.T198479142A198490249. https://dx.doi.org/10.2305/IUCN.UK.2021-2.RLTS.T198479142A198490249.en .Accessed on 26 September 2023

Country occurrence