Megalaria grossa
ENEndangered

Megalaria grossa

Local name: ädellav

Megalaria grossa, commonly known as ädellav, is a crustose lichen species characterized by its thick, warty thallus that forms grayish-white to pale yellow crusty patches on bark surfaces. This slow-growing epiphytic lichen plays a crucial ecological role as a pioneer species in forest ecosystems, contributing to nutrient cycling and providing microhabitat for invertebrates while serving as an indicator of air quality and forest health.

Photo: iNaturalist: (c) Steve Kerr, some rights reserved (CC BY), uploaded by Steve Kerr

01Classification

Taxonomy & Classification

Kingdom

Fungi

Phylum

Ascomycota

Class

Lecanoromycetes

Order

Lecanorales

Family

Ramalinaceae

Genus

Megalaria

Megalaria grossa belongs to the family Ramalinaceae, order Lecanorales, within the Lecanoromycetes class.

02Description

Species Profile

Megalaria grossa, commonly known as ädellav, is a crustose lichen species characterized by its thick, warty thallus that forms grayish-white to pale yellow crusty patches on bark surfaces. This slow-growing epiphytic lichen plays a crucial ecological role as a pioneer species in forest ecosystems, contributing to nutrient cycling and providing microhabitat for invertebrates while serving as an indicator of air quality and forest health.

Megalaria grossa faces severe population declines primarily due to habitat loss from deforestation and forest degradation in its limited range. The species is particularly vulnerable due to its specialized ecological requirements and small population size, making it highly susceptible to environmental changes and human disturbance.

Key Facts

IUCN StatusEndangered (EN)
GroupFungi
03Habitat

Habitat & Distribution

Ädellav typically colonizes the bark of mature deciduous trees, particularly favoring the slightly acidic bark of oak, beech, and maple trees in old-growth and semi-natural forests. The species requires stable microclimatic conditions with consistent humidity levels and minimal air pollution, often found in forest interiors away from urban and agricultural influences.

TERRESTRIALMajor
04Threats

Threats

!

IUCN Red List: Endangered

Megalaria grossa faces severe population declines primarily due to habitat loss from deforestation and forest degradation in its limited range. The species is particularly vulnerable due to its specialized ecological requirements and small population size, making it highly susceptible to environmental changes and human disturbance.

Deforestation and habitat loss

HighOngoing

Forest degradation from logging

HighOngoing

Air pollution affecting lichen substrates

MediumOngoing

Climate change affecting suitable habitat

MediumOngoing

Small population size and genetic bottlenecks

MediumOngoing
Community

Community Sightings

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07Sources

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). Megalaria grossa (Megalaria grossa). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/adellav

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