Common Rim Lichen vs Polar bear

Lecanora pulicaris compared with Ursus maritimus

Key Differences

Common Rim Lichen is Least Concern while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Common Rim Lichen	Polar bear
Kingdom	Fungi (真菌界)	Animalia (动物界)
Phylum	Ascomycota (子囊菌门)	Chordata (脊索动物门)
Class	Lecanoromycetes (茶漬綱)	Mammalia (哺乳動物)
Order	Lecanorales (茶漬目)	Carnivora (食肉目)
Family	Lecanoraceae	Ursidae (Bears)
Genus	Lecanora	Ursus (Bears)
Species	Lecanora pulicaris	Ursus maritimus

Conservation Status

Common Rim Lichen

LC — Least Concern

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common Rim Lichen	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Common Rim Lichen

Habitat

Native to Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, Portugal, Sweden, and United States.

Polar bear

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Rim Lichen

<em>Lecanora pulicaris</em>, the common rim lichen, is a crustose lichen in the family Lecanoraceae, order Lecanorales, within the kingdom Fungi (as the mycobiont component). It is distributed across temperate and boreal zones, with documented records from Denmark, Norway, Portugal, Sweden, and the United States. The species is assessed as Least Concern on the IUCN Red List, reflecting its widespread occurrence on bark of deciduous and coniferous trees across the Northern Hemisphere. Rim lichens in the genus Lecanora are characterized by their apothecia — disc-shaped reproductive structures rimmed by a thallus margin — which give the genus its common name. <em>Lecanora pulicaris</em> typically forms pale gray-green crustose patches on smooth to moderately rough bark surfaces, particularly favoring the bark of birch, alder, and other hardwood trees in well-lit forest and woodland environments. As a lichen, it is a symbiotic organism comprising a fungal partner (mycobiont) and photosynthetic algal or cyanobacterial partners (photobionts), deriving nutrients through photosynthesis and mineral absorption from the substrate. Biological traits such as lifespan and growth rates remain poorly documented for this taxon, though crustose lichens typically grow very slowly. It serves as a bioindicator of air quality in temperate forests.