Grey knight

Description

The grey knight is a greyish tricholoma with a cap 3–8 cm across, conical when young, then spread out with an umbo. The cuticle is dry, finely scaly or fibrous, in ash-grey shades. The gills are white, turning grey with age, the stem white or greyish-white, without a ring and without a volva.

It grows from September to November in coniferous and mixed forests, especially under pines, in dense groups; in late autumn it can be very abundant. In Poland it is common.

Grey tricholomas resemble one another. The ashen knight and Polish gąska ostra have a burning taste, and the tiger tricholoma is poisonous. At the slightest doubt, do not collect or eat it.

Identification features

Cap

Diameter 3–8 cm; conical when young, then spread out, usually with an umbo; cracked in older specimens. Colour pale grey to dark grey, often with a paler margin. Cuticle dry, felty-fibrous, scaly (fine grey scales). Flesh in the cap thin.

Hymenophore (underside of the cap)

Gills brittle, notched, distant to moderately crowded (descriptions also say fairly crowded), thin, notched with a tooth, adnate to almost free. At first white, later ash-grey.

Stem

Height 3–8 cm (descriptions give different ranges), thickness up to 1.6 cm, cylindrical, solid, sometimes slightly curved. White or greyish-white, bare or with delicate, cobwebby veil remnants. Without a ring and without a volva.

Flesh

White or greyish, thin, brittle, does not change colour. Smell and taste mild, not mealy (according to some descriptions mild to slightly mealy). Do not taste unknown mushrooms.

Spore print and spores

Spore print white. Spores ovoid (oval), smooth, colourless. Size 5–8 × 3.5–5 µm (descriptions give different ranges).

Habitat and distribution

Ecology. Mycorrhizal fungus. Grows on the ground among fallen needles and leaves, in coniferous and mixed forests, especially under pines (also spruces), on sandy and calcareous soils; found in parks under conifers. Grows in dense groups, sometimes forms fairy rings.

Distribution. Widespread: Europe, North America, Asia, Africa, Australia and New Zealand (under introduced pines). In Poland common. Not legally protected.

Fruiting. From September to November, in mild winters also in December; in late autumn it sometimes appears in large numbers.

What can it be confused with?

• Tricholoma virgatum (the ashen knight; Polish: gąska pieprzna) — Cap sharply conical, without fibres; taste burning (peppery).
• Tricholoma atrosquamosum (Polish: gąska czarnołuskowa) — Blackish scales on the cap.
• Tricholoma portentosum (the coalman; Polish: gąska niekształtna) — Cap without scales, stem yellowish, taste mild, nutty.
• Tricholoma sciodes (Polish: gąska ostra) — Cap silky-shiny, taste acrid.
• Tricholoma pardinum (the tiger tricholoma; Polish: gąska tygrysia) — Larger, poisonous; smell mealy, distinct scales on the cap.
• Tricholoma orirubens — Fine dark scales and pinkish gills.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• The English name "grey knight" refers to the gills, which change colour and turn grey.
• The species was already described in 1762 by Jacob Christian Schäffer.
• In 2014 reports appeared about the toxicity of tricholomas (rhabdomyolysis), which later studies significantly weakened.
• The species also occurs under introduced pines in Australia and New Zealand.