Kaernefeltia californica (current, 1996, (Tuck.) Thell & Goward)
Cornicularia californica (1926, (Tuck.) Du Rietz)
Coelocaulon californicum (1912, (Tuck.) Howe)
Alectoria californica (1910, (Tuck.) Merrill)
Cetraria californica (1859, Tuck.)

Taxon synonym: Alectoria cetrariza (1887, (Tuck.) Nylander)

Kingdom: Fungi, Phylum: Ascomycota, Class: Lecanoromycetes, Order: Lecanorales, Family: Parmeliaceae

The average size for this species is < 2-3 cm in diameter (McCune, p. 103), and is “typically richly fertile” (Thell & Goward, p. 126).

There are many misidentified records of Kaernefeltia californica in herbaria. All of the non-coastal records of the Consortium of Lichen Herbaria are most likely Kaernefeltia merrillii or Nodobryoria abbreviata (McCune, p. 103).

Kaernefeltia californica is a globally imperiled (G2) species endemic to the Pacific Northwest coast of North America. In the United States, it is considered to be imperiled (S2) in Washington, vulnerable (S3) in Oregon, and apparently secure (S4) in British Columbia, Canada (NatureServe 2025).

Kaernefeltia californica is endemic to the Pacific Northwest coast of North America. It occurs in patchy locations from SE Alaska to southern California, where it is restricted to the immediate coast (McCune & Geiser, p. 103).

The global population size of Kaernefeltia californica has been overestimated in the past due to the fact that 33% of the georeferenced herbarium records (34/102) represent misidentifications of Kaernefeltia merrillii or Nodobryoria abbreviata. Moreover, 70% of K. californica herbarium records are more than 40 years old; 18% are more than 100 years old. This highlights the need to verify herbarium specimens and regularly monitor rare lichen populations (CLH, 2025).

Kaernefeltia californica global populations are estimated to have decreased by 50% in the last approximately 150 years due to habitat loss caused by coastal development and habitat structural changes. The generation length of Cetraria californica is assumed to be ~15-20 years based on the length of time required for colonization of new substrate and the time required to grow to maturity and reproduce. Under generation categories, K. californica would be listed as a medium-to-long-lived: slow growing, long-term stable substratum associate (Yahr et al 2024). This species is also at increased risk of extinction and recolonization due to its small size and the fact that >50% of the global population for this species occur in small, isolated sub-populations across the species range (Yahr et al 2024).

Grows on Pinus contorta (Lodgepole Pine) and Picea sitchensis (Sitka Spruce) forests in coastal sand dunes near the ocean. Typically on conifer twigs and less often on shrubs (McCune, p. 103).

However, it does colonize fence posts or other wooden structures at low elevations, usually no more than a few meters above sea level. In northern parts of its range, it will grow on twigs, cones, and bark of living P. contorta and on Pinus muricata (Bishop Pine) in other areas (Thell & Goward, p. 126).

Systems: Epiphytic, fruticose.

Habitat loss due to coastal development, rising sea levels and over-collection are the primary threats to this species.

When the species is found, record data on population size and health, but do not collect specimens, because over-collection is thought to be a contributing factor for the species decline.

Disseminate updated conservation assessments (i.e. IUCN Red List, NatureServe, WHNP) to educate land managers about threats and declines. Designate Westport Lighthouse State Park in WA state as a Natural Resources Conservation Area. This site one of the only known localities in WA where this species has been successfully relocated in the last 40 years and this site supports several other rare lichen and coastal plant communities (Dunwiddie, 2021). This designation would afford a higher degree of protection for this rare coastal habitat and would prevent the habitat from future development while still allowing for low-impact activities such as hiking, mushroom foraging, bird watching and camping.

Develop a detailed conservation and management plan for Kaernefeltia californica and other rare lichens at sites where it occurs.

Re-survey historical collection sites for Kaernefeltia californica to determine current population status. As well as conduct new surveys of suitable habitat in coastal areas to locate potentially new populations, especially in Washington state where populations appear to be at high risk of extirpation.

Due to this species being identifiable through photographs, using platforms like iNaturalist is helpful in documenting its presence.

Whether or not this lichen has an economic importance, cross checking listed herbariums for correct species, and revisiting historical sites. There are many misidentified herbarium records of Kaernefeltia californica. All of the non-coastal records of the Consortium of Lichen Herbaria are most likely Kaernefeltia merrillii or Nodobryoria abbreviata.

Not economically significant/not known.