Phaeocollybia californica was described from California, USA (Smith 1957). 

Phaeocollybia rufotubulina (Norvell 2004) is a synonym (Norvell pers. comm.).

Phaeocollybia californica is an uncommon mushroom with a disjunct distribution in northern California and Oregon coast and Coast Range, and scattered sites in the Oregon Cascade Range foothills.

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 ~125 records from ~60 locations; mostly in California, in an habitat that continues to decline.

In coastal and Coast Range forests from northern California into northern Oregon, and scattered locations in the SIskiyou Range, and Cascade Foothills in Oregon.

Populations of Phaeocollybia californica is widespread, but highly disjunct. 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.

Phaeocollybia californica is currently known from ~125 records, from ~60 locations (MyCoPortal 2021) in California and Oregon, USA, although some of these sites are no longer extant (Norvell & Exeter 2009). Most of these occurrences are in mature and old growth forests.

Phaeocollybia californica is ectomycorrhizal with conifers; especially Douglas-fir (Pseudotsuga menziesii), Grand Fir, (Abies grandis), and Western Hemlock (Tsuga heterophylla), and possibly Tanoak (Notholithocarpus densiflorus).

This species may be restricted to mature and old growth forests. Fruiting in small to large clusters in soil, typically in areas with thick duff. Fruiting in fall.

Phaeocollybia californica is an 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 is included on the United States Forest Service Northwest Forest Plan Survey and Manage list of rare/old growth forests dependent fungi, and has been actively surveyed for since the late 1990’s (Castellano et al. 1999)

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

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 March 21.

Norvell, L.L. 2004. Phaeocollybia in western North America 4: Two new species with tibiiform cheilocystidia and Section Versicolores reconsidered. Mycotaxon. 90(2):241-260

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