Assessment Notes

Justification

Leccinum montanum is a bolete described from aspen groves in the Sierra Nevada mountains of California. While uncommon, the species has been recorded in multiple states across the western USA mountains (Siegel et al. 2019, MyCoPortal 2024) and it is probably more common than records indicate. Leccinum are in need of modern taxonomic work, especially species reported from California. However, for now, the species is assessed as Least Concern due to the reported wide distribution of this species in aspen groves across the western United States.

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Taxonomic notes

Leccinum in general are taxonomically confounded by lack of informative morphological criteria, as well as poorly-known and competing species concepts. Leccinum montanum should be compared genetically with L. californicum; a white-capped but otherwise very similar species, which co-occurs with this species at two of the four known sites in California. It should also be compared to other Leccinum described from eastern North American aspen forests.

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Geographic range

This species is known from three sites in the Sierra Nevada mountains of California, and six highly disjunct subpopulations in the Cascade Range and Rocky Mountains, and a single collection from Alaska. This species is probably widespread with Quaking Aspen (Populus tremuloides) in the western mountains.

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Population and Trends

The population appears to occur over a widespread area (California north to Washington State and Alaska, and from multiple states in the Rocky Mountain), but very little is known about trends of this species. No collections have been made in California since 1983, although this may be a case of mycologists not looking for it, or identifying it correctly. Targeted surveys at known localities are needed to assess things more clearly.

Population Trend: Unknown

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Habitat and Ecology

Fruitbodies are solitary or scattered in soil and duff, and it is presumably ectomycorrhizal and associated with Quaking Aspen (Populus tremuloides) in higher elevations of the Sierra Nevada, Cascades and Rocky Mountains. Fruiting occurs in summer and early fall.

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Threats

Declines in aspen groves in the Sierra Nevada, due in part to conifer encroachment from fire suppression, and cattle grazing are likely to be negatively impacting the species.

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Conservation Actions

This species was included in A Field Guide to the Rare Fungi of California’s National Forests (Siegel et al. 2019), and was recommended for the Forest Service sensitive species list. Although aspen restoration projects are ongoing, effort should be made to cause minimal damage to the duff and understory. Targeted surveys of aspen groves in the Sierra Nevada and southern Cascade Range in California are needed to document the species’ distribution and population size and trends. Modern taxonomic work on Leccinum is also needed to resolve taxonomic issues.

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Use and Trade

Leccinum are edible and occasionally collected by foragers.

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Source and Citation

Siegel, N. & Mueller, G.M. 2025. Leccinum montanum. The IUCN Red List of Threatened Species 2025: e.T198480532A198488578. Accessed on 23 November 2025.

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