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Kaernefeltia californica

(Tuck.) Thell & Goward

Coastal Thornbush Lichen

G2Imperiled Found in 1 roadless area NatureServe Explorer →
G2ImperiledGlobal Rank
HighThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.124026
Element CodeNLT0000100
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryFungus
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomFungi
PhylumAscomycota
ClassLecanoromycetes
OrderLecanorales
FamilyParmeliaceae
GenusKaernefeltia
Synonyms
Cetraria californicaTuck.Cornicularia californica(Tuck.) Du Rietz
Concept Reference
Thell, A. and T. Goward. 1996. The new cetrarioid genus Kaernefeltia and related groups in the Parmeliaceae (lichenized Ascomycotina). The Bryologist 99(2):125-136.
Taxonomic Comments
Formerly Cetraria californica: Esslinger and Egan (1995) agree that it belongs in a separate genus which had yet to be described in 1995. This species is frequently confused with Cetraria merrillii and Nodobryoria abbreviata but neither of these species occur in maritime forests. Misidentified specimens have frequently been reported from inland areas so distribution maps are often incorrect (McCune and Geiser 2023).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-03-03
Change Date2025-03-03
Edition Date2025-03-03
Edition AuthorsChristy, John (2001), Johnson, J. (2025)
Threat ImpactHigh
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Kaernefeltia californica is a fruticose lichen that is native to the west coast of North America, from Alaska to central California, where it is restricted to coastal areas. It may face threats from logging, development, and sea level rise, and populations in Washington have experienced recent declines in population and occupied area.
Range Extent Comments
Kaernefeltia californica is native to the west coast of North America, from Alaska to central California (CLH 2025). Range extent was estimated using herbarium specimens and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, NatureServe 2025, CLH 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium records and NatureServe Network occurrence data documented between 1994 and 2025, and anecdotal evidence, there are 31 occurrences rangewide (GBIF 2025, NatureServe 2025, CLH 2025, Dean et al. 2025).
Threat Impact Comments
The coastal forest habitat that Kaernefeltia californica occupies is threatened by logging, residential development, golf course development, and sea level rise (Dean 2025).
Ecology & Habitat

Habitat

Kaernefeltia californica grows on bark, twigs, cones and fence posts in pine or spruce forest, dwarf forest, and chaparral, particularly around the edges of coastal dunes (CLH 2025).

Reproduction

Kaernefeltia californica generation length is estimated to be 20-30 years (Calabria 2025).
Terrestrial Habitats
Forest/WoodlandForest - ConiferForest EdgeWoodland - ConiferShrubland/chaparralSand/duneCropland/hedgerow
Other Nations (2)
United StatesN2
ProvinceRankNative
WashingtonS1Yes
OregonS3Yes
CanadaN4
ProvinceRankNative
SaskatchewanSUYes
British ColumbiaS4Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undeterminedUnknownUnknownUnknown
1 - Residential & commercial developmentLarge (31-70%)Serious or 31-70% pop. declineHigh (continuing)
1.1 - Housing & urban areasLarge (31-70%)Serious or 31-70% pop. declineHigh (continuing)
1.3 - Tourism & recreation areasRestricted (11-30%)Serious or 31-70% pop. declineModerate (short-term)
5 - Biological resource useRestricted (11-30%)Moderate or 11-30% pop. declineModerate (short-term)
5.3 - Logging & wood harvestingRestricted (11-30%)Moderate or 11-30% pop. declineModerate (short-term)
11 - Climate change & severe weatherRestricted (11-30%)Extreme or 71-100% pop. declineModerate (short-term)
11.1 - Habitat shifting & alterationRestricted (11-30%)Extreme or 71-100% pop. declineModerate (short-term)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (1)
Oregon (1)
AreaForestAcres
TenmileSiuslaw National Forest10,818
References (12)
  1. Calabria, Lalita. 2025. Personal communication via email about research on <i>Kaernefeltia californica. </i>Faculty at Evergreen State College.
  2. Consortium of Lichen Herbaria. 2025. https://lichenportal.org/portal/index.php (accessed 2025).
  3. Dean, Isabel. 2025. Personal communication via email about recent survey efforts for <i>Kaernefeltia californica. </i>Student at Evergreen State College.
  4. Dean, I., Sharrett, S., and Calabria, L. IUCN Global Red List Assessment for the Coastal Thornbush Lichen Cetraria californica (Tuck.). Unpublished poster presentation for Northwest Lichenologists conference. 2025.
  5. Esslinger, T. L. 2018. A cumulative checklist for the lichen-forming, lichenicolous and allied fungi of the continental United States and Canada, Version 22. Opuscula Philolichenum 17:6-268. [http://sweetgum.nybg.org/philolichenum/]
  6. Esslinger, T.L. and R.S. Egan. 1995. A sixth checklist of the lichen-forming, lichenicolous, and allied fungi of the continental United States and Canada. The Bryologist 98(4): 467-549.
  7. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  8. Goward, T., B. McCune, and D. Meidinger. 1994. The Lichens of British Columbia Illustrated Keys, Part 1- Foliose and Squamulose Species. Ministry of Forests Research Program, Victoria, British Columbia. 181 pp.
  9. McCune, B. and L. Geiser. 1997. Macrolichens of the Pacific Northwest. Oregon State University Press, Corvallis, Oregon. A co-publication with the U.S. Department of Agriculture Forest Service. 386 pp.
  10. McCune, B. and L. Geiser. 2023. Macrolichens of the Pacific Northwest, Third Edition, Revised and Expanded. ISBN 9780870712517
  11. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  12. Thell, A. and T. Goward. 1996. The new cetrarioid genus Kaernefeltia and related groups in the Parmeliaceae (lichenized Ascomycotina). The Bryologist 99(2):125-136.