Brook Floater vs Common Pellia

Alasmidonta varicosa compared with Pellia epiphylla

Taxonomic Classification

Rank	Brook Floater	Common Pellia
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Mollusca (Mollusks)	Marchantiophyta (liverwort)
Class	Bivalvia (Bivalvia)	Jungermanniopsida (Jungermanniopsida)
Order	Unionida (Unionida)	Pelliales (Pelliales)
Family	Unionidae	Pelliaceae
Genus	Alasmidonta	Pellia
Species	Alasmidonta varicosa	Pellia epiphylla

Conservation Status

Brook Floater

VU — Vulnerable

Common Pellia

VU — Vulnerable

Physical Characteristics

Attribute	Brook Floater	Common Pellia
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 Pellia

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (7 countries), and North America (United States). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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 Pellia

<em>Pellia epiphylla</em>, known as the common pellia, is a thallose liverwort in the family Pelliaceae and one of the most frequently encountered bryophytes in temperate regions. It grows in dense, dark-green mats typically found along stream banks, wet rock faces, moist woodland floors, and other persistently damp habitats where it can absorb water directly through its undifferentiated thallus. The species is distributed across Europe, including Belgium, Denmark, Luxembourg, Norway, and Portugal, as well as parts of Asia including Taiwan and North America including the United States, reflecting a broadly circumboreal range. <em>Pellia epiphylla</em> reproduces both sexually, producing distinctive stalked spore capsules in spring, and vegetatively through fragmentation. It is currently assessed as Vulnerable on the IUCN Red List, indicating that populations face moderate risk due to habitat loss and degradation associated with wetland drainage, water pollution, and land-use change. Biological traits such as average lifespan, thallus dimensions, and detailed ecological requirements remain poorly documented compared to vascular plants. The species is ecologically important as a pioneer on disturbed moist soils and contributes to moisture retention in riparian ecosystems.