Black Knapweed vs Common Fieldcap

Centaurea nigra compared with Agrocybe pediades

Key Differences

Black Knapweed is Not Evaluated while Common Fieldcap is Least Concern.

Taxonomic Classification

Rank	Black Knapweed	Common Fieldcap
Kingdom	Plantae (Plants)	Fungi (Fungi)
Phylum	Magnoliophyta (Flowering Plants)	Basidiomycota (Club Fungi)
Class	Magnoliopsida (Dicots)	Agaricomycetes (Mushrooms)
Order	Asterales (Daisies & Sunflowers)	Agaricales (Gilled Mushrooms)
Family	Asteraceae (Daisy Family)	Strophariaceae
Genus	Centaurea	Agrocybe
Species	Centaurea nigra	Agrocybe pediades

Conservation Status

Black Knapweed

NE — Not Evaluated

Common Fieldcap

LC — Least Concern

Physical Characteristics

Attribute	Black Knapweed	Common Fieldcap
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Black Knapweed

Habitat

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

Range

Widely distributed across Asia (Japan), Europe (7 countries), North America (Canada, United States), Oceania and the Pacific (Australia), and South America (Chile).

Common Fieldcap

Habitat

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

Range

Found across Europe (5 countries) and North America (United States).

Black Knapweed

The Black Knapweed (Centaurea nigra) is a species in the genus Centaurea. Typically found in diverse terrestrial habitats from tropical forests to temperate regions. Its geographic range spans Widely distributed across Asia (Japan), Europe (7 countries), North America (Canada, United States), Oceania and the Pacific (Australia), and South America (Chile).

Common Fieldcap

The Common Fieldcap (<em>Agrocybe pediades</em>) is a saprotrophic fungus belonging to the genus Agrocybe within the family Strophariaceae. It typically produces small, tan to pale brown cap-shaped fruiting bodies and is often found growing in clusters or scattered on lawns, grassy areas, forest floors, decomposing wood, and soil-rich ecosystems. The species typically inhabits forest floors, decomposing wood, and soil ecosystems, obtaining nutrients by breaking down dead organic matter. Its geographic range includes several European countries — Belgium, Denmark, Norway, Portugal, and Sweden — as well as the United States in North America. <em>Agrocybe pediades</em> is assessed as Least Concern on the IUCN Red List, reflecting its broad distribution and apparent stability. Biological traits of this species, including specific data on fruiting body size, lifespan, and ecological preferences, remain poorly documented in the scientific literature. Like other members of its genus, it typically fruits during warmer months and often appears after rainfall in nutrient-rich grassland and woodland habitats.