Rubroboletus pulcherrimus is an uncommon bolete known from Northern California and the Pacific Northwest. Most populations are from old growth forests, in coastal habitats. 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 records. This species is listed on the Washington Natural Heritage Program List of Rare Macrofungi as a S1. It is relatively commonly reported from California. This is a large, brightly colored species.  Given its high detectability it is conservatively estimated that there are only up to 50-100X more individuals than the approximately 250 records known, resulting in a precautionary population size of around 12,500 - 25,000 mature individuals. It is likely that the species’s population is decreasing due to coastal development and logging in its primary habitat. The species is assessed as Near Threatened.

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.

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

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, Arizona, and one observation from Michoacan, Mexico; these collections should be critically compared with CA material, and with Rubroboletus haematinus; they are more likely conspecific with the latter species and are excluded from this assessment.

Rubroboletus pulcherrimus is 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.  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 records. This species is listed on the Washington Natural Heritage Program List of Rare Macrofungi as a S1. While it is rare to uncommon in Oregon and Washington State, there are 50 records (mycoportal.org) from California and a large majority of the over 200 observations reported on inaturalist.org (Dec. 2024) are from California. This is a large, brightly colored species.  Given its high detectability it is conservatively estimated that there are only up to 50- 100 x more individuals than recorded, resulting in a precautionary population size of around 12,500 - 25,000 mature individuals.  It is likely that the species’s population is decreasing due to coastal development and logging in its primary habitat.

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.

Loss of habitat due to coastal development. and logging of mature forests.

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

Surveys to better document this species distribution and population trends are needed.  Additionally, habitat data should be noted when this species is found as it may be restricted to mature and old growth forests.

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