Pyrenula coryli
Local name: hasselvårtlav
Pyrenula coryli, known as hasselvårtlav, is a crustose lichen species that forms thin, grayish to brownish crusts on bark surfaces. This inconspicuous lichen plays an important ecological role in forest ecosystems by contributing to nutrient cycling and providing microhabitat for small invertebrates.
Taxonomy & Classification
Kingdom
Fungi
Phylum
Ascomycota
Class
Eurotiomycetes
Order
Pyrenulales
Family
Pyrenulaceae
Genus
Pyrenula
Pyrenula coryli belongs to the family Pyrenulaceae, order Pyrenulales, within the Eurotiomycetes class.
Species Profile
Pyrenula coryli, known as hasselvårtlav, is a crustose lichen species that forms thin, grayish to brownish crusts on bark surfaces. This inconspicuous lichen plays an important ecological role in forest ecosystems by contributing to nutrient cycling and providing microhabitat for small invertebrates. Its small, dark perithecia (fruiting bodies) are embedded in the thallus surface, making identification challenging without close examination.
Pyrenula coryli (hasselvårtlav) is critically endangered primarily due to habitat loss and degradation of old-growth deciduous forests, particularly those containing its preferred host trees. Air pollution and changes in forest management practices have severely reduced suitable habitat, while the species' extremely limited distribution makes it highly vulnerable to local extinctions.
Key Facts
Habitat & Distribution
Hasselvårtlav grows exclusively on the smooth bark of mature deciduous trees, particularly favoring hazel (Corylus) species in old-growth and semi-natural woodland environments. It requires stable microclimatic conditions with consistent humidity levels and minimal air pollution, typically found in undisturbed forest interiors.
Threats
IUCN Red List: Critically Endangered
Pyrenula coryli (hasselvårtlav) is critically endangered primarily due to habitat loss and degradation of old-growth deciduous forests, particularly those containing its preferred host trees. Air pollution and changes in forest management practices have severely reduced suitable habitat, while the species' extremely limited distribution makes it highly vulnerable to local extinctions.
Air pollution and acid rain
Changes in forest management practices
Extremely small population size and limited distribution
Habitat loss and forest fragmentation
Climate change affecting host tree health
Community Sightings
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Sources & Attribution
How to Cite
IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS
GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org
This page: SpeciesRadar (2025). Pyrenula coryli (Pyrenula coryli). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/hasselvartlav