Clustered Brown Bolete vs Polar bear

Aureoboletus innixus compared with Ursus maritimus

Key Differences

Clustered Brown Bolete is Not Evaluated while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Clustered Brown Bolete	Polar bear
Kingdom	Fungi (真菌界)	Animalia (动物界)
Phylum	Basidiomycota (担子菌门)	Chordata (脊索动物门)
Class	Agaricomycetes (傘菌綱)	Mammalia (哺乳動物)
Order	Boletales (牛肝菌目)	Carnivora (食肉目)
Family	Boletaceae	Ursidae (Bears)
Genus	Aureoboletus	Ursus (Bears)
Species	Aureoboletus innixus	Ursus maritimus

Conservation Status

Clustered Brown Bolete

NE — Not Evaluated

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Clustered Brown Bolete	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Clustered Brown Bolete

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Found in 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.

Clustered Brown Bolete

Aureoboletus innixus, the clustered brown bolete, is a mycorrhizal basidiomycete fungus in the family Boletaceae native to eastern North America, particularly associated with oak (Quercus) forests from New England south to the southeastern United States. The fruiting bodies are medium-sized boletes with a brown, velvety to dry cap surface, yellow to olive-yellow pores and tubes on the underside, and a stipe that may have a yellowish ground color with brownish fibrils. A distinctive feature is the tendency to fruit in clustered groups at the base of oak trees, sometimes arising from a shared mycelial cord or attached to each other at the stipe bases. The pores do not blueñ when cut or bruised, distinguishing it from some other boletoid species. A. innixus forms ectomycorrhizal associations with oaks, providing trees with enhanced nutrient and water uptake in exchange for photosynthetic carbohydrates. The species has not been formally evaluated by the IUCN for conservation status. It is considered a relatively uncommon but regularly encountered species in appropriate oak woodland settings in the eastern US.