Agrocybe arvalis

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Agrocybe arvalis

In a pot with Mentha spicata (spearmint). 19 October 2013 Hampshire. Photograph copyright Leif Goodwin

Cap

Convex, expanding, smooth, sometimes wrinkled, margin sometimes lined, ochraceous to pale yellow, to about 5 cm across

Gills

Adnate, fairly broad, brown

Stem

Slender, cylindrical, pruinose, rooting, pale ochraceous to pale yellow

Flesh

Firm, pale yellow

Smell

Indistinct

Taste

Bitter

Season

Autumn

Distribution

Rare

Habitat

On soil in woods and on soil mulched with wood chips

Spore Print

Dark brown

Microscopic Features

Spores ellipsoidal, smooth (8-12) x (4.5-6) µm2. Gill edge cystidia lageniform. Gill face cystidia lageniform, sometimes with 3 to 5 long finger like projections. Cap cuticle cystidia lageniform. Stem cystidia lageniform.

Edibility

Unknown

Notes

The fungus emerges from a buried pea sized mass known as a sclerotium. In the case of the specimens in the photographs, numerous off white sclerotia were visible at the soil surface many months before the fungus emerged, although at the time I had no idea what they were. This species is easily recognised under the microscope by the presence of gill face cystidia with finger like projections. Note that some of the specimens shown are far more robust than usual.

Additional Photographs

Agrocybe arvalis

The slender forms to the right are more typical of the species. 19 October 2013 Hampshire. Photograph copyright Leif Goodwin

Agrocybe arvalis

Spores in Congo red viewed with a x100 immersion objective and x2.5 projection eyepiece. 19 October 2013 Hampshire. Photograph copyright

Agrocybe arvalis

A gill face cystidium with finger like projections in Congo red viewed with a x40 objective and x2.5 projection eyepiece. 19 October 2013 Hampshire. Photograph copyright Leif Goodwin

Agrocybe arvalis

Gill edge cystidia in Congo red viewed with a x40 objective and x2.5 projection eyepiece. 19 October 2013 Hampshire. Photograph copyright Leif Goodwin

Agrocybe arvalis

Cap cuticle cystidia in Congo red viewed with a x40 objective and x2.5 projection eyepiece. 19 October 2013 Hampshire. Photograph copyright Leif Goodwin