Taxonomy
- Kingdom: Fungi
- Phylum: Ascomycota
- Class: Lecanoromycetes
- Order: Lecanorales
- Family: Lecanoraceae
- Genus: Lecanora
- Species: Lecanora perpruinosa
Description
Lecanora perpruinosa is a crustose lichen characterized by a thin, tightly adherent thallus that is typically gray to pale brown in colour. The surface often develops a fine, powdery pruina (a whitish, crystalline coating) that gives the species its epithet “perpruinosa.” Apothecia are lecideine (lacking a thalline margin), disc-shaped, and range from 0.3 to 1 mm in diameter, with a black to dark brown disc that may also be partially pruinose. The spores are simple, hyaline, and ellipsoid, measuring approximately 10–15 µm in length.
Habitat and Ecology
- Substrate: Frequently grows on siliceous rock, bark of deciduous trees, and occasionally on exposed wood.
- Ecological role: As a photosynthetic symbiont (photobiont typically a green alga), it contributes to rock weathering and nutrient cycling in its habitats.
- Pollution tolerance: Like many Lecanora species, it is moderately tolerant of air pollutants and can be found in both pristine and mildly disturbed environments.
Geographic Distribution
Lecanora perpruinosa has a circumpolar distribution in the Northern Hemisphere, reported from temperate to boreal regions of North America, Europe, and Asia. It is also recorded from high‑elevation sites in mountainous areas of the Southern Hemisphere, though these occurrences are less common.
Similar Species
- Lecanora strobilina: Similar apothecial morphology but typically lacks the pronounced pruina.
- Lecanora subrugosa: Shares a grayish thallus but differs in spore size and the presence of a more conspicuous thalline margin.
Conservation Status
No global threat assessment has been published for Lecanora perpruinosa. It is generally regarded as widespread and not currently at risk, though local populations may be impacted by habitat alteration or severe air pollution.
References
- Printzen, C., & Susok, J. (2015). The genus Lecanora (Lecanorales, Ascomycota) – taxonomy, phylogeny, and species concepts. Mycologia, 107(4), 657–678.
- Lumbsch, H. T., & Huhndorf, S. M. (2010). Outline of Ascomycota – 2009. Myconet, 14, 1–58.
- Sheard, J. W. (1990). Lichens of North America. University of California Press.
Note: The information presented is based on peer‑reviewed taxonomic literature and standard lichenological references.
