coast amaranth vs Collared Mosscap

Amaranthus pumilus compared with Rickenella swartzii

Key Differences

coast amaranth is Extinct while Collared Mosscap is Least Concern.

Taxonomic Classification

Rank	coast amaranth	Collared Mosscap
Kingdom	Plantae (Plants)	Fungi (Fungi)
Phylum	Magnoliophyta (Flowering Plants)	Basidiomycota (Club Fungi)
Class	Magnoliopsida (Dicots)	Agaricomycetes (Mushrooms)
Order	Caryophyllales (Caryophyllales)	Hymenochaetales (Hymenochaetales)
Family	Amaranthaceae	Rickenellaceae
Genus	Amaranthus	Rickenella
Species	Amaranthus pumilus	Rickenella swartzii

Conservation Status

coast amaranth

EX — Extinct

Collared Mosscap

LC — Least Concern

Physical Characteristics

Attribute	coast amaranth	Collared Mosscap
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

coast amaranth

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Found in Japan.

Collared Mosscap

Habitat

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

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

coast amaranth

Coast amaranth (Amaranthus pumilus) is an annual herb in the family Amaranthaceae, native to the Atlantic and Gulf coasts of the eastern United States, where it once grew on coastal foredunes, beach strand, and shell-hash substrates above the high tide line from New York south to South Carolina. It is a low-growing, fleshy plant with small, rounded leaves and inconspicuous green flowers typical of the genus. Coast amaranth is assessed as Extinct in the Wild by the IUCN, as it has not been reliably documented from wild populations since the mid-20th century; the last confirmed collections date to the 1960s. The species' decline and likely extinction resulted from intense human pressure on Atlantic coastal habitats through shoreline development, beach stabilisation, vehicular traffic on beaches, and increased storm frequency disrupting pioneer dune vegetation. It is federally listed as Threatened in the United States, though this listing predates confirmed extinction in the wild. A small number of ex-situ accessions may exist in botanical garden collections. Genetic material and seed banking efforts represent the only remaining conservation options for this critically reduced species.

Collared Mosscap

The Collared Mosscap, known scientifically as <em>Rickenella swartzii</em>, is a small fungus belonging to the family Repetobasidiaceae within the order Agaricales. <em>Rickenella swartzii</em> is characterised by its diminutive fruiting bodies, which typically feature a small, convex to umbilicate cap and a slender stipe. The species typically grows in mossy substrates, on forest floors, decomposing wood, and soil, where it plays a role in nutrient cycling as a saprotrophic or potentially mycorrhizal organism. It is reported to occur in Belgium, Denmark, Norway, and Sweden, reflecting a distribution across parts of northern Europe. Detailed biological traits including typical lifespan measures and physical dimensions are poorly documented for this fungal species in available literature. The Collared Mosscap is currently assessed as Least Concern on the IUCN Red List, indicating that it is not considered to be at significant risk of global population decline.