Common Nut Truffle vs small tortoiseshell

Hymenogaster vulgaris compared with Aglais urticae

Key Differences

• Common Nut Truffle is Data Deficient while small tortoiseshell is Near Threatened.

Taxonomic Classification

Rank	Common Nut Truffle	small tortoiseshell
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Basidiomycota (Club Fungi)	Arthropoda (Arthropods)
Class	Agaricomycetes (Mushrooms)	Insecta (Insects)
Order	Agaricales (Gilled Mushrooms)	Lepidoptera (Butterflies & Moths)
Family	Hymenogastraceae	Nymphalidae (Brush-footed Butterflies)
Genus	Hymenogaster	Aglais
Species	Hymenogaster vulgaris	Aglais urticae

Conservation Status

Common Nut Truffle

DD — Data Deficient

small tortoiseshell

NT — Near Threatened

Physical Characteristics

Attribute	Common Nut Truffle	small tortoiseshell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Nut Truffle

Habitat

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

Range

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

small tortoiseshell

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (41 countries). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Common Nut Truffle

<em>Hymenogaster vulgaris</em>, the common nut truffle, is a hypogeous (below-ground) fungus in the family Hymenogastraceae, order Agaricales. This sequestrate species produces enclosed, truffle-like fruiting bodies that mature underground and rely primarily on small mammals and invertebrates for spore dispersal, as the sporocarps never open to release spores aerially. <em>Hymenogaster vulgaris</em> typically forms ectomycorrhizal associations with hardwood tree species, particularly oaks and beeches, in temperate European forests. Its geographic range includes Denmark, Norway, Portugal, Sweden, and the United States, reflecting a somewhat scattered distribution across temperate zones. The species is currently assessed as Data Deficient by the IUCN, indicating that insufficient information exists to evaluate its conservation status, likely because hypogeous fungi are difficult to survey and their population trends are poorly known. Biological traits such as lifespan, body size, and diet remain poorly documented for this species. As an ectomycorrhizal fungus, <em>Hymenogaster vulgaris</em> plays a critical role in facilitating nutrient uptake in host trees and supporting forest health across its temperate range.

small tortoiseshell

small tortoiseshell (Aglais urticae) is classified as Near Threatened (NT) on the IUCN Red List. Close to qualifying as threatened, with populations that may become vulnerable without conservation action.

Shared Countries

Both species can be found in 4 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇵🇹 Portugal 🇸🇪 Sweden