Brook Floater vs Common Nut Truffle

Alasmidonta varicosa compared with Hymenogaster vulgaris

Key Differences

• Brook Floater is Vulnerable while Common Nut Truffle is Data Deficient.

Taxonomic Classification

Rank	Brook Floater	Common Nut Truffle
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Mollusca (Mollusks)	Basidiomycota (Club Fungi)
Class	Bivalvia (Bivalvia)	Agaricomycetes (Mushrooms)
Order	Unionida (Unionida)	Agaricales (Gilled Mushrooms)
Family	Unionidae	Hymenogastraceae
Genus	Alasmidonta	Hymenogaster
Species	Alasmidonta varicosa	Hymenogaster vulgaris

Conservation Status

Brook Floater

VU — Vulnerable

Common Nut Truffle

DD — Data Deficient

Physical Characteristics

Attribute	Brook Floater	Common Nut Truffle
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Brook Floater

Habitat

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

Range

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

Brook Floater

The Brook Floater (Alasmidonta varicosa) is a species in the genus Alasmidonta. It is currently classified as Vulnerable on the IUCN Red List. Native to North America, inhabiting ecosystems characteristic of the region.

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.

Shared Countries

Both species can be found in 1 countries:

🇺🇸 United States