• Proposed
  • Under Assessment
  • Preliminary Assessed
  • Assessed
  • VUPublished

Umbilicaria phaea var. coccinea Llano

Search for another species...

Scientific name
Umbilicaria phaea var. coccinea
Common names
IUCN Specialist Group
Assessment status
Assessment date
IUCN Red List Category
IUCN Red List Criteria
McMullin, T., Calabria, L., Glew, K., Villella, J., Sheehy, S., Peterson, E. & Allen, J.
Lendemer, J.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/80703145/80703148


Umbilicaria phaea var. coccinea is endemic to northwestern continental United States. It is a distinctive and conspicuous taxon due to its bright red thallus. Therefore, it is unlikely to have been overlooked in areas that have been explored by lichenologists or by general botanists. It is only known to be locally common in the arid portions of a single watershed. There are approximately six sites outside of this watershed with very low numbers of individuals (one to a few small thalli). The largest subpopulation is comprised of roughly 200 functional individuals, and the total population size is estimated to be between 8,500-9,500 extant functional individuals. There is a continuing decline in the habitat quality and extent where U. phaea var. coccinea occurs due to housing and infrastructure development, along with off-road vehicle recreation. This is inferred to be causing a continuing decline in the population. Therefore, it is Vulnerable (C2a(i)).

Taxonomic notes

Chemical and ecological data support the circumscription of this variety. Current molecular data do not support the monophyly of Umbilicaria phaea var. coccinea as a distinct lineage from Umbilicaria phaea var. phaea (Allen et al. 2022).

Geographic range

Umbilicaria phaea var. coccinea is endemic to northwestern North America and has been reported from northern California, Oregon, and Washington (Allen et al. 2022). Most individuals have been reported from the Klamath Canyon and the Shasta River.

Population and Trends

Umbilicaria phaea var. coccinea is locally somewhat common in arid portions of the Klamath River watershed on both sides of the California/Oregon border. Outside of the Klamath River watershed there are approximately six known sites with low numbers of individuals (one to a few small thalli) in central Oregon and two sites in Washington along the Columbia River.

Population Trend: decreasing

Habitat and Ecology

Umblicaria phaea var. coccinea only occurs in arid environments on exposed basalt and ultramafic rock.


Development of commercial areas and roads, and habitat loss are the primary threats to this taxon. Off-road vehicle recreation is the second most serious threat to Umbilicaria phaea var. coccinea. Dam removal activities along the Klamath River could disturb or extirpate occurrences. Increased fire activity within its range and collection may also pose a threat to this visually striking taxon.

Conservation Actions

In Washington, the Northwest Lichenologists conducted a review and  recommended a state conservation rank of S1 (critically imperiled). This is currently under review by the Washington Natural Heritage Program. In California, this variety is considered rare (Sharnoff 2014). A bid for conservation sponsorship is currently being prepared for the Conservation Committee of the California Lichen Society by J. Villella and E. Peterson. In Oregon, U. phaea var. coccinea has a Natural Heritage state rank of S2 (imperiled).

The much more common brown variety, Umbilicaria phaea var. phaea, almost always occurs adjacent to the red variety. It is uncertain if the two varieties are interbreeding. Further research is required to better understand their relationship, which may be important for conservation planning.

Climatic models show potential habitat in eastern Washington and eastern Oregon that may not have been explored (Allen et al. 2022), and continued research on the taxonomic status, population sizes, and distribution of this taxon is needed. Monitoring population trends and developing a long-term management plant would aid substantively in the conservation of Umbilicaria phaea var. coccinea.

Use and Trade

Umbilicaria phaea var. coccinea is collected for scientific research.

Source and Citation

McMullin, T., Calabria, L., Glew, K., Villella, J., Sheehy, S., Peterson, E. & Allen, J. 2022. Umbilicaria phaea var. coccinea. The IUCN Red List of Threatened Species 2022: e.T80703145A80703148. https://dx.doi.org/10.2305/IUCN.UK.2022-1.RLTS.T80703145A80703148.en .Accessed on 31 July 2023

Country occurrence