Calamus vs Cobweb weaver

Acorus calamus compared with Steatoda nobilis

Key Differences

Calamus is Least Concern while Cobweb weaver is Not Evaluated.

Taxonomic Classification

Rank	Calamus	Cobweb weaver
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Arthropoda (Arthropods)
Class	Liliopsida (Monocots)	Arachnida (Arachnids)
Order	Acorales (Acorales)	Araneae (Araneae)
Family	Acoraceae	Theridiidae
Genus	Acorus	Steatoda
Species	Acorus calamus	Steatoda nobilis

Conservation Status

Calamus

LC — Least Concern

Cobweb weaver

NE — Not Evaluated

Physical Characteristics

Attribute	Calamus	Cobweb weaver
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Calamus

Habitat

Inhabits tropical and subtropical moist broadleaf forests and tropical and subtropical coniferous forests within the Indomalayan biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (South Africa), Asia (5 countries), Europe (30 countries), and North America (Canada, United States).

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).

Calamus

The Calamus (Acorus calamus) is a species in the genus Acorus. It is currently classified as Least Concern on the IUCN Red List. Inhabits tropical and subtropical moist broadleaf forests and tropical and subtropical coniferous forests within the Indomalayan biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

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.