Brook Floater vs Common Fieldcap

Alasmidonta varicosa compared with Agrocybe pediades

Key Differences

Brook Floater is Vulnerable while Common Fieldcap is Least Concern.

Taxonomic Classification

Rank	Brook Floater	Common Fieldcap
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Mollusca (Mollusks)	Basidiomycota (Club Fungi)
Class	Bivalvia (Bivalvia)	Agaricomycetes (Mushrooms)
Order	Unionida (Unionida)	Agaricales (Gilled Mushrooms)
Family	Unionidae	Strophariaceae
Genus	Alasmidonta	Agrocybe
Species	Alasmidonta varicosa	Agrocybe pediades

Conservation Status

Brook Floater

VU — Vulnerable

Common Fieldcap

LC — Least Concern

Physical Characteristics

Attribute	Brook Floater	Common Fieldcap
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 Fieldcap

Habitat

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

Range

Found across Europe (5 countries) and North America (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 Fieldcap

The Common Fieldcap (<em>Agrocybe pediades</em>) is a saprotrophic fungus belonging to the genus Agrocybe within the family Strophariaceae. It typically produces small, tan to pale brown cap-shaped fruiting bodies and is often found growing in clusters or scattered on lawns, grassy areas, forest floors, decomposing wood, and soil-rich ecosystems. The species typically inhabits forest floors, decomposing wood, and soil ecosystems, obtaining nutrients by breaking down dead organic matter. Its geographic range includes several European countries — Belgium, Denmark, Norway, Portugal, and Sweden — as well as the United States in North America. <em>Agrocybe pediades</em> is assessed as Least Concern on the IUCN Red List, reflecting its broad distribution and apparent stability. Biological traits of this species, including specific data on fruiting body size, lifespan, and ecological preferences, remain poorly documented in the scientific literature. Like other members of its genus, it typically fruits during warmer months and often appears after rainfall in nutrient-rich grassland and woodland habitats.