A formerly cryptic species in the Phaeocollybia kauffmanii complex; until it was described by Norvell (2000), from Van Damme State Park, in Mendocino County, California, USA.

Before that Phaeocollybia benzokauffmanii was included in the concept of Phaeocollybia kauffmanii. Past collections have been examined and properly identified, and this species has been included in a recent guides (Desjardin et al. 2015, Siegel et al. 2019), so most current records are being correctly identified.

Phaeocollybia benzokauffmanii is an uncommon mushroom with a disjunct distribution on the northern California coast, and coast to western Cascades in Oregon and Washington.

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.

There appears to be ~25 locations (Mycoportal 2021), although Norvell & Exeter (2008) referenced “~35 localities from northwestern California into northern Washington”.

Known from disjunct populations from coastal Mendocino County, California, USA north into Washington in coastal, Coast Range and lower elevations of the Cascade Range in Oregon and Washington.

Population is widespread, but highly disjunct. 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.

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. 

Ectomycorrhizal with conifers, and possibly Tanoak (Notholithocarpus densiflorus), apparently 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 brethren is habitat destruction, via the logging of old-growth forests to which it appears confined too. 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).

Fire is big threat to this species’ populations. A stand replacing fire could severely degrade and/or diminish its current range. Logging and machine clearing of understory vegetation should be limited in mature and old growth forest in areas where this species might occur.

This species should be added to the United States Forest Service Northwest Forest Plan Survey and Manage list of rare/old growth forests dependent fungi.

Continued surveys for existing populations. A better understanding of habitat restraints and requirements;  is it restricted to old growth?

None known.

Desjardin, D.E., Wood, M.G. and Stevens, F.A. 2015. California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 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. 2021. http://mycoportal.org/portal/index.php. Accessed on February 12.

Norvell, L.L. 2000. Phaeocollybia in Western North America 1: The Phaeocollybia kauffmanii complex. Canadian Journal of Botany. 78(8): 1055-1076.

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.