Phaeocollybia californica

Mycobank (2025) include Phaeocollybia rufotubulina in Phaeocollybia californica, while Species Fungorum (2025) treat them as distinct.

Only 7 populations are confirmed as extant by this author, although more are likely to be determined from southern Oregon where Quercus is more common. There are only 5 currently protected occurrences, but 3 occurrences may no longer be extant. The most immediate threat is infection by the Phytophthora species causing ""suddent oak death"" in California and southern Oregon. The populations are also at risk from hot fires, heavy logging or development. Total predicted occurrences may be ~30-40 and reinspection of recent collections may confirm some collections in the ISMS database as representing P californica. The spotty distribution and unpredictable phenology common to all phaeocollybias complicate ranking this organism.

Endemic to the northern spotted owl region in western North America and known only in coastal and coast range locations in Oregon from Cape Meares south to Jedediah Smith State Park and east to Castle Crags State Park in California, The ISMS 2002 PHCA40 map shows two species: Phaeocollybia californica and P scatesiae. From 1977 until 1998, the two species were considered synonymous.

The ISMS 2002 database erroneously cites 44 Phaeocollybia californica occurrences in the northern spotted owl region. When the current author evaluated herbarium collections, she accepted the synonymy of P scatesiae with P californica proposed in 1977. After formal recognition of two separate species in 1998, Norvell notified the Regional Mycology Lab regarding the change in taxonomic status, but correction to the existing database appears incomplete. Of the original 17 PHCA40 occurrences submitted, only 8 (none believed extant), represent P californica. The 2002 ISMS database and PHCA40 map includes 5 original PHSC sites. Due to this confusion as well as the presumed difficulty in nonexperts distinguishing between the two species, only 18 occurrences (7 extant) verified by this author, are cited here. Other S&M collections made from habitats containing Quercus, however, are also likely to represent P californica. Unfortunately those habitat data are not available to this author (Norvell 1995, 1998ab, pers. comm. 2002).

Ectomycorrhizal fungal stability depends on the stability of its symbiotic partners, so what threatens extant forests threatens the organism. This species appears restricted to late-successional old-growth mixed coniferous-fagaceous forests (Norvell 1998ab, Norvell pers. comm. 2002). It also appears to grow slowly. (Norvell 1998ab) Would be threatened by hot fires, development, and heavy logging activities. The most immediate and serious threat is the rise of the Phytophthora pathogen in California forests associated with ""sudden oak death"", the presumed preferred mycorrhizal partner of P. californica.