Agrocybe erebia - Dark Fieldcap

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

An occasional find, the Dark Fieldcap, Agrocybe erebia, is a woodland fungus; its cap colour is very variable, sometimes with a centre so dark that it appears to be almost jet black. (The rings are not yet evident because the partial veils are still intact in thee young specimens shown here.)

Many of the fieldcaps can have darkish caps when young, but Agrocybe erebia is the only one that remains dark brown through to maturity rather than fading to buff.

Identification Guide

Cap	4 to 7cm across, hemispherical becoming broadly umbonate; the brown surface pales towards the margin but does not fade, as other fieldcaps do, at maturity.
Gills	Adnate or very slightly decurrent; initially pale brown, turning dark brown as the spores mature.
Stem	5 to 10cm long and 0.7 to 1.2cm dia.; cylindrical; whitish streaked with brown, darker towards base; retaining a persistent, pendulous pallid ring with radial striations.
Spore print	Dark brown.
Odour/taste	Not distinctive
Habitat	In tufts, saprobic onthe litter of hardwood and softwood forest floors; occasionally on well-rotted woodchip mulch.
Season	June to October.
Occurrence	Uncommon.
Similar species	Agrocybe praecox, which occurs in spring and early summer, often grows in woodchip mulch; it is typically smaller and usually has a cap that becomes paler with age.