Elaphomyces subviscidus is an extremely rare species; currently only known from three sites in Oregon, two of which are historic. It is also reported from single collections from Idaho, Utah and Colorado, however discrepancies with spore measurements call into question the identity of these reports and they are not included in this assessment.  Elaphomyces subviscidus is listed as G2 (Globally Imperiled) by NatureServe ).  It is listed as a sensitive species by the USDA Forest Service and subjected to strategic surveys, yet no new locations have been found in 20 plus years of random and strategic surveys. While truffle-like fungi are challenging to detect, given that there has been dedicated surveys for this species and other truffle-like fungi in the region for over 50 years, it is unlikely that there are numerous additional locations.  Conservatively, there could be 50-100 X more sites, each with up to 4 mature individuals, resulting in a population size of 800-1600. Past and ongoing habitat decline throughout the regions likely has had a negative impact on the species. Out of caution, the species is listed as Endangered.

Described as Scleroderma subviscidum (Zeller 1947) from a collection made in Jackson County, Oregon. Later transferred to Elaphomyces (Trappe and Guzmán 1971) where is resides today.
Some of the collections going by the name Elaphomyces subviscidus are likely misidentified. The Colorado collection was made under Ponderosa Pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii), and has substantially larger spores; the Utah collection was made under White Fir (Abies concolor) and Ponderosa Pine. More investigation is warranted, as these may pertain to distinct species.

Many western North American Elaphomyces species are using misapplied European epithets, or have not had any species name attached to them; work is under way resolving this.

Elaphomyces subviscidus is an extremely rare species; currently only known from three sites in Oregon, two of which are historic. It is also reported from single collections from Idaho, Utah and Colorado, however discrepancies with spore measurements call into question
the identity of these reports.

Known from three locations in high elevation forest in the Oregon Cascade and Coast Range, and reported from single sites in Idaho, Utah and Colorado, but these Rocky Mountain collections should be scrutinized.

The species is currently reported from three locations in Oregon, and two isolated sites one in Idaho and the other in Utah, but the Idaho Fish and Game Department site (https://idfg.idaho.gov/) says that the species does not occur in the state. And, a reported observation from Colorado is likely of a different taxon and is not included in this assessment).  Two of the Oregon collections are historic records. It has been found at a location in the Oregon Coast Range under Noble fir (Abies procera) more recently. Elaphomyces subviscidus is listed as G2 (Globally Imperiled) by NatureServe (https://explorer.natureserve.org/ Dec 2024).  It is listed as a sensitive species by the USDA Forest Service (Castellano et al. 1999) and subjected to strategic surveys, yet no new locations have been found in 20 plus years of random and strategic surveys. While truffle-like fungi are challenging to detect, dedicated surveys for them in Oregon and surrounding states have been ongoing for decades. Thus, it is likely that this is a very rare species. Given that there has been dedicated surveys for this species and other truffle-like fungi in the region for over 50 years, it is unlikely that there are numerous additional locations.  Conservatively, there could be 50-100 X more sites, each with up to 4 mature individuals, resulting in a population size of 800-1600.  Past and ongoing habitat decline throughout the regions likely has had a negative impact on the species.

Hypogeous, solitary or scattered in duff or soil under Lodgepole Pine (Pinus contorta), Western Hemlock (Tsuga heterophylla), and Mountain Hemlock (Tsuga mertensiana). Ectomycorrhizal. The type collection was exposed (“above ground on decayed granite soil”). This species is dependent on mycophagy (primarily eaten by small mammals) for spore dispersal.

More sites need to be discovered to properly assess and understand the range of suitable habitats, and their specific threats.

Protect known sites from management activities, including logging, fuels reduction, or other development and disturbance.

Continued collecting of and work on the taxonomy of Elaphomyces in western North America is needed.

None known.

Castellano, M., Smith, J.E., O’Dell, T., Cázares, E. and Nugent, S. 1999. Handbook to Strategy 1 Fungal Species in the Northwest Forest Plan. General Technical Report PNW-GTR-476. United States Department of Agriculture.

Fogel, R. and Trappe, J.M. 1976. Additions to the hypogeous mycoflora of Colorado. I. Ascomycetes. Mycotaxon 4(1): 211–217.

gbif.org (December 2024)

https://idfg.idaho.gov/species/taxa/61965

https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.637167/Elaphomyces_subviscidus

Oregon Biodiversity Information Center. 2016. Rare, Threatened and Endangered Species of Oregon. Institute for Natural Resources, Portland State University, Portland, Oregon.

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.

Trappe, J.M. and Guzmán, G. 1971. A newly determined species of Elaphomyces from Oregon. Madroño 21: 128–130.

Zeller, S.M. 1947. More notes on Gasteromycetes. Mycologia 39: 282–312.