Club Grain-Spored Lichen vs Polar bear

Sarcogyne clavus compared with Ursus maritimus

Key Differences

Club Grain-Spored Lichen is Data Deficient while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Club Grain-Spored Lichen	Polar bear
Kingdom	Fungi (菌界)	Animalia (動物)
Phylum	Ascomycota (子嚢菌門)	Chordata (脊索動物)
Class	Lecanoromycetes (チャシブゴケ菌綱)	Mammalia (哺乳類)
Order	Acarosporales (Acarosporales)	Carnivora (ネコ目)
Family	Acarosporaceae	Ursidae (Bears)
Genus	Sarcogyne	Ursus (Bears)
Species	Sarcogyne clavus	Ursus maritimus

Conservation Status

Club Grain-Spored Lichen

DD — Data Deficient

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Club Grain-Spored Lichen	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Club Grain-Spored Lichen

Habitat

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

Range

Distributed across Denmark, Norway, 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.

Club Grain-Spored Lichen

Sarcogyne clavus is a crustose lichen in the family Acarosporaceae, forming closely appressed, granular to warty grey-white thalli on calcareous rocks, concrete, mortar, and exposed mineral substrates. The species is characterized by its distinctive club-shaped or clavate ascospores, from which its specific name derives. Like other Sarcogyne species, it produces apothecia that are typically lecideine (lacking a thalline margin), dark-colored, and often somewhat convex. This lichen favors exposed, sunny rock faces with high calcium content, including limestone outcrops, old walls, and stone monuments. S. clavus is distributed across Europe and North America, occurring primarily in calcareous rock habitats. As a pioneer colonizer of bare rock, it contributes to the initial stages of ecological succession by weathering the substrate and accumulating organic matter. The IUCN lists this species as Data Deficient, reflecting insufficient data on its population size, distribution, and ecology to assess its conservation status with confidence. Lichens as a group are sensitive to air pollution, but calcicolous crustose lichens on exposed rock may be less vulnerable than foliose or fruticose species.

Polar bear

地球上で最大の陸上肉食動物であるホッキョクグマは700kgを超えることがあり、カナダからロシアまでの北極海氷域全体に分布する。ワモンアザラシとヒゲアザラシを狩るために海氷に依存する高度に特化した海洋哺乳類である。広大な距離を泳ぐことができる優れた泳者でもある。脆弱種に指定されており、気候変動による急激な北極海氷の消失で個体群が深刻な圧力を受けている。