Phaeocollybia pseudofestiva population is widespread, but highly disjunct. It is currently known from ~35 locations and 50 plus records. This species may be restricted to mature and old growth forests. Suitable habitat is now rare and fragmented, continuing to decline in both quality and geographic extent. The scarcity of remnant old growth and mature forests in the Coast Range and Cascade foothills, and their fragmented condition are a major cause for concern; it is unknown if this species is capable of colonizing and persisting in younger forests.  Steel et al. (2023) calculated that over 30% of the conifer forests in the Southern Sierra Nevada Mountains transitioned to nonforest vegetation between 2011-2020 and that between 50%-85% of mature forests significantly declined in quality during this time.  Extrapolating these data to more northern California into Washington State yields a conservative estimate of a loss / decline of at least 30% of habitat for this species over the past three generations and continuing into the future.  It is assessed as Vulnerable A2c+3c+4c.

Described from a Type collection made near Crescent City, California, USA (Smith 1957).

Phaeocollybia pseudofestiva is often mistaken for the more common Phaeocollybia olivacea and P. fallax. All three can grow in close proximity; some collections identified as P. pseudofestiva contain fruitbodies of one or both of these species (Norvell & Exeter 2009).

Phaeocollybia pseudofestiva is an uncommon mushroom with a disjunct distribution on the northern California to British Columbia coast and Coast Range, and scattered sites in the Oregon Cascade Range.

This species appears to be restricted to mature and old growth forests. Suitable habitat is now rare and fragmented, continuing to decline in both quality and geographic extent.

Currently known from ~35 locations; mostly in Oregon.

Known from disjunct populations from coastal Mendocino County, California, USA north to Vancouver Island, British Columbia, Canada in Cast and Coast Range forests, and scattered location in the Cascade Range in Oregon.

Its population is widespread, but highly disjunct. It is currently known from ~35 locations and 50 plus records (Norvell & Exeter 2009, Siegel et al. 2019, Mycoportal 2024). This species may be restricted to mature and old growth forests. Suitable habitat is now rare and fragmented, continuing to decline in both quality and geographic extent. The scarcity of remnant old growth and mature forests in the Coast Range and Cascade foothills, and their fragmented condition are a major cause for concern; it is unknown if this species is capable of colonizing and persisting in younger forests. Steel et al. (2023) calculated that over 30% of the conifer forests in the Southern Sierra Nevada Mountains transitioned to nonforest vegetation between 2011-2020 and that between 50%-85% of mature forests significantly declined in quality during this time.  Extrapolating these data to more northern California into Washington State and southern British Colombia yields a conservative estimate of a loss / decline of at least 30% of habitat for this species over the past three generations and continuing into the future. 

Ectomycorrhizal with conifers, and possibly Tanoak (Notholithocarpus densiflorus), and possibly restricted to late seral stage and old growth forests. Fruitbodies solitary or scattered in small patches, appearing in fall and early winter.

This is a ectomycorrhizal fungus species dependent on living host trees for viability. The major threat to this species and its co-occurring co-generic taxa is habitat destruction, via the logging of old-growth forests to which this species has a preference for and an increase in fire frequency and intensity. The extent of old growth forest in the Pacific Northwest of North America has declined 90% in the last century (Society of American Foresters 1984, Haynes 1986). Climate change and droughts, along with forest management practices has made western forests highly susceptible to stand replacing forest fires. Fire is big threat to this species’ populations. A stand replacing fire could severely degrade and/or diminish its current range.

This species is included on the United States Forest Service Northwest Forest Plan Survey and Manage list of rare/old growth forests dependent fungi (Castellano et al. 2003), and has been actively surveyed for since the late 1990’s.  Logging and machine clearing of understory vegetation should be limited in mature and old growth forest in areas where this species might occur.

Continued surveys for existing populations to better understand population trends and habitat restraints and requirements; is it restricted to old growth?

Castellano, M.A., Cázares, E., Fondrick, B. and Dreisbach, T. (2003). Handbook to additional fungal species of special concern in the Northwest Forest Plan (Gen. Tech Rep. PNW-GTR-572). U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: Portland, OR. 144 p.

Haynes, T.W. 1986. Inventory and value of old-growth in the Douglas-fir region. PNW-RN 437. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Portland, OR.

MyCoPortal. 2024. http://mycoportal.org/portal/index.php. Accessed on February 12.

Norvell, L.L. and Exeter, R.L. 2009. Phaeocollybia of Pacific Northwest North America. US Department of Interior, BLM: Salem, OR. 229 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.

Society of American Foresters. 1984. Scheduling the harvest of old growth : Old-growth forests in the Pacific Northwest : a position of the Society of American Foresters and Report of the SAF Task Force on Scheduling the Harvest of Old-Growth Timber. Bethesda, MD.
Steel, Zachary L., Gavin M. Jones, Brandon M. Collins, Rebecca Green, Alexander Koltunov, Kathryn L. Purcell, Sarah C. Sawyer, et al. 2023. “ Mega-Disturbances Cause Rapid Decline of Mature Conifer Forest Habitat in California.” Ecological Applications 33(2): e2763. https://doi.org/10.1002/eap.2763