Assessment Notes

Justification

Phlyctis petraea is a rock-dwelling species that is abundant throughout eastern North America. Its occurs in a diversity of habitats and its population size is currently inferred to be stable. Given the large number sites where it is extant, large geographic range, large population size, and absence of documented or suspected declines, the species does not meet the thresholds for any threat criteria. Thus, it is considered Least Concern.

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Taxonomic notes

As is discussed in detail by Muscavitch et al. (2017), Phlyctis petraea has been collected for nearly a century, and recognized as distinct for more than fifty years. However it was only formally described in 2017.

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Geographic range

Phlyctis petraea is endemic to North America where it is widespread in the eastern United States and parts of adjacent Canada (Muscavitch et al. 2017).

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Population and Trends

Complete, detailed population data are unavailable for this taxon. However, it is suspected to be stable as it is common and widespread in many different habitats (Muscavitch et al. 2017).

Population Trend: stable

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Habitat and Ecology

Although Phlyctis petraea has a wide geographic distribution in temperate eastern North America, it grows almost exclusively on sheltered and protected rock overhangs (Muscavitch et al. 2017). Nearly all known occurrences are from non-calcareous rocks, especially sandstones, however it has occasionally been found on calcareous rocks such as limestone. A small number of records are from the bases of hardwood trees.

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Threats

The primarily threat to Phlyctis petraea is urbanization as it does not typically occur in urban areas. Otherwise it occurs at sites that span a wide range of habitat qualities.

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Conservation Actions

Many sites where Phlyctis petraea occurs are located on public lands and in protected areas where it is incidentally protected. This species would benefit from broader awareness and training as to the impacts of urbanization generally on lichens. Moreover, this species would benefit from demographic studies and long-term monitoring of both habitat and population trends.

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Use and Trade

Phlyctis petraea has been used to study the impacts of climbing on crustose rock-dwelling lichens (Clark and Hessl 2015) and to study remote detection of lichen communities (Wasklewicz et al. 2007).

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Source and Citation

Lendemer, J. 2022. Phlyctis petraea. The IUCN Red List of Threatened Species 2022: e.T180096965A180097016. https://dx.doi.org/10.2305/IUCN.UK.2022-1.RLTS.T180096965A180097016.en .Accessed on 1 August 2024

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• Country occurrence