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  • Under Assessment
  • 3Preliminary Assessed
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Rubroboletus pulcherrimus (Thiers & Halling) D. Arora, N. Siegel & J.L. Frank

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Scientific name
Rubroboletus pulcherrimus
(Thiers & Halling) D. Arora, N. Siegel & J.L. Frank
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Under Assessment
Proposed by
Noah Siegel
Noah Siegel
Comments etc.
James Westrip

Assessment Notes


Rubroboletus pulcherrimus is an uncommon bolete known from Northern California and the Pacific Northwest. Most populations are from old growth forests, in coastal habitats.

Taxonomic notes

Until the past decade, the nomenclature and taxonomy of California’s ‘Satan’s Boletes’ was somewhat confounded.

The name Boletus (Rubroboletus) eastwoodiae was misapplied to this species; what we now know as Rubroboletus eastwoodiae went by the misapplied name Boletus satanas. Thiers & Halling, (1976) described Boletus pulcherrimus as a new species, and follow-up work has shown that B. satanas is strictly a European species, and the correct name for the Californian oak-associated Satan’s Bolete is B. eastwoodiae.

More recently, these species were transferred to the genus Rubroboletus.

Why suggested for a Global Red List Assessment?

Rubroboletus pulcherrimus is an uncommon bolete known from Northern California and the Pacific Northwest. Most populations are from old growth forests, in coastal habitats.

Geographic range

Occurring on the coast of California, USA; from Salt Point in Sonoma County, north to the Olympic Peninsula in Washington. Also found in lower elevation forest in the Klamath Range, and western Cascades north through Washington into south-central British Columbia, Canada. Reported from New Mexico and Arizona; these collections should be critically compared with CA material, and with Rubroboletus haematinus; they are more likely conspecific with the latter species.

Population and Trends

Currently known from ± 40 locations, over a widespread area. Most California records are from protected coastal forests (in state and National Parks). Although it doesn’t appears to be restricted to old growth forests, it has a strong preference for them. Not enough population data is available to show trends of this species. 

Rubroboletus pulcherrimus (as Boletus pulcherrimus) is listed as a sensitive species by the USDA Forest Service (Castellano et al. 1999), and subjected to strategic surveys, yet still has a low number of known populations.

This species is listed on the Washington Natural Heritage Program List of Rare Macrofungi as a S1.

Population Trend: Uncertain

Habitat and Ecology

Ectomycorrhizal with conifers, likely restricted to true firs (Abies) and hemlock (Tsuga). Growing in soil or duff, often in dense, mid-to-late seral stage and old growth forests. Fruiting in late summer and fall, rarely in winter or spring.

Temperate Forest


Loss of habitat due to coastal development. Logging of mature forests.

Housing & urban areasUnintentional effects: large scale (species being assessed is not the target) [harvest]

Conservation Actions

Many populations are known from protected lands, but some occur on USFS land, where logging should be prohibited in areas this species occurs.

Site/area protection

Research needed

Habitat data should be noted when this species is found, as it may be restricted to mature and old growth forests.

Population size, distribution & trendsLife history & ecology

Use and Trade

None known.


Castellano, M.A., Smith, J.E., O’Dell, T., Cázares, E. and Nugent, S. 1999. Handbook to Strategy 1 Fungal Species in the Northwest Forest Plan. U. S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: Portland, OR. 195 p.

Frank, J.L. 2015. Nomenclatural novelties. Index Fungorum no. 248: 1.

MyCoPortal. 2020. Mycology Collections Portal. Available at: http://mycoportal.org

Siegel, N. and Schwarz, C. 2016. Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.

Siegel, N., Vellinga, E.C., Schwarz, C., Castellano, M.A. and Ikeda, D. 2019. A Field Guide to the Rare Fungi of California’s National Forests. Bookmobile: Minneapolis, MN. 313 p.

Thiers, H.D. and Halling, R.E. 1976. California Boletes V. Two new species of Boletus. Mycologia 68: 976-983.

Washington Natural Heritage Program List of Macrofungi https://www.dnr.wa.gov/publications/amp_nh_macrofungi.pdf


Country occurrence

Regional Population and Trends

Country Trend Redlisted