Brook Floater vs Common Button Lichen

Alasmidonta varicosa compared with Buellia erubescens

Key Differences

Brook Floater is Vulnerable while Common Button Lichen is Not Evaluated.

Taxonomic Classification

Rank	Brook Floater	Common Button Lichen
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Mollusca (Mollusks)	Ascomycota (Sac Fungi)
Class	Bivalvia (Bivalvia)	Lecanoromycetes (Lecanoromycetes)
Order	Unionida (Unionida)	Caliciales (Caliciales)
Family	Unionidae	Caliciaceae
Genus	Alasmidonta	Buellia
Species	Alasmidonta varicosa	Buellia erubescens

Conservation Status

Brook Floater

VU — Vulnerable

Common Button Lichen

NE — Not Evaluated

Physical Characteristics

Attribute	Brook Floater	Common Button Lichen
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 Button Lichen

Habitat

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

Range

Distributed across Norway, Portugal, Sweden, Taiwan, 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 Button Lichen

<em>Buellia erubescens</em>, commonly known as the common button lichen, is a lichen species with documented occurrences across Asia, Europe, and North America, including countries such as Norway, Portugal, Sweden, Taiwan, and the United States. It typically colonizes diverse terrestrial surfaces, often found on bark, rock, or other substrates in temperate and boreal environments. Common button lichen belongs to the genus <em>Buellia</em> within the family Caliciaceae. As a crustose lichen, it typically forms tightly adhered, crust-like thalli on the surfaces it colonizes, making it characteristic of stable, undisturbed substrates. Biological traits such as average lifespan, thallus size, and biomass of this species remain poorly documented in the scientific literature. The species has not yet been formally evaluated by the IUCN, and its global conservation status therefore remains undetermined. Its occurrence across multiple continents suggests a wide ecological tolerance, though detailed population data and trend assessments are currently lacking for this taxon.