Coastal Mushoom vs Cobweb weaver

Agaricus litoralis compared with Steatoda nobilis

Key Differences

Coastal Mushoom is Least Concern while Cobweb weaver is Not Evaluated.

Taxonomic Classification

Rank	Coastal Mushoom	Cobweb weaver
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Basidiomycota (Club Fungi)	Arthropoda (Arthropods)
Class	Agaricomycetes (Mushrooms)	Arachnida (Arachnids)
Order	Agaricales (Gilled Mushrooms)	Araneae (Araneae)
Family	Agaricaceae (Agarics)	Theridiidae
Genus	Agaricus (Button Mushrooms)	Steatoda
Species	Agaricus litoralis	Steatoda nobilis

Conservation Status

Coastal Mushoom

LC — Least Concern

Cobweb weaver

NE — Not Evaluated

Physical Characteristics

Attribute	Coastal Mushoom	Cobweb weaver
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Mushoom

Habitat

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

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Cobweb weaver

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Europe (7 countries), North America (United States), and South America (Ecuador).

Coastal Mushoom

Agaricus litoralis, the coastal mushroom, is a saprotrophic agaric fungus in the family Agaricaceae occurring in sand dunes, coastal grassland, and sandy soil habitats along the coasts of northwestern Europe, with confirmed records from Belgium, Denmark, Norway, and Sweden. The genus Agaricus contains the familiar cultivated button mushroom (A. bisporus) along with hundreds of wild species, and members are characterized by a ring on the stem and browning, discoloring, or non-discoloring flesh when cut, features used in field identification. Agaricus litoralis is a medium-sized mushroom producing white to cream-colored caps 4–10 centimeters across with pinkish then dark brown gills and a stout stem with a double ring, fruiting in sand dune hollows and the grassy margins of coastal habitats from summer through autumn. The specific epithet litoralis refers directly to its coastal habitat preference. As a saprotroph, it decomposes organic matter in the sandy soil substrate, releasing nutrients back into the ecosystem. The species is classified as Least Concern by the IUCN, being relatively widespread in suitable coastal sandy habitat across northwestern Europe. Like many coastal fungi, it is specifically adapted to the nutrient-poor, well-drained, alkaline conditions of stabilized sand dune systems.

Cobweb weaver

The noble false widow (Steatoda nobilis) is a theridiid spider that has attracted considerable media attention in the British Isles and along the Atlantic coast of Europe due to its painful but rarely dangerous bite and its rapid range expansion facilitated by human activity. Originally native to the Canary Islands and Madeira, the species arrived in southern England during the 19th century, likely via banana shipments, and has since spread northward through Britain and westward into Ireland, while also establishing populations along the Iberian Peninsula and Atlantic France. Females are robust, with a dark brown carapace and a distinctive cream-colored pattern on the bulbous abdomen that varies between individuals; females reach 8.5–14 millimeters in body length, making this one of the larger European theridiids. The species constructs persistent, tangled cobwebs in sheltered locations outside buildings—under window ledges, in door frames, and in garden walls—as well as within homes in cooler seasons. It is a generalist predator, capturing insects and other invertebrates, and has been reported to occasionally subdue prey considerably larger than itself, including small lizards. Steatoda nobilis venom produces steatodism, which can cause localized pain, swelling, and in rare cases systemic symptoms. Its conservation status has not been formally assessed, but its expanding range demonstrates considerable resilience.