Grey Knight

Habitat

This mushroom is primarily found on the ground or leaf litter in coniferous and mixed woodlands. It shows a strong preference for pine but is also found with spruce or Douglas-fir, particularly within plantations. It typically grows in small groups, scattered clusters, or fairy rings.

Photos

Appearance

Cap

1.5–9 cm wide; ranging from conical or bell-shaped to convex, often developing a low, broad umbo and flattening with age; color is mouse gray to dark grayish-black, sometimes brownish-gray or lighter toward the wavy, inrolled margin; texture is dry, downy, felty, or matted-tomentose, often covered in tiny gray to black scales or fibers.

Stem

2–9 cm long, 0.4–1.5 cm thick; cylindrical or slightly bulbous at the base; white to pale gray, sometimes discoloring yellowish when handled; surface is silky-smooth to finely fibrous or downy, especially at the apex.

Gills

Attached with a notch (emarginate to adnexed) or appearing nearly free; white to pale gray, occasionally with darker spots; spacing varies from close to relatively distant; broad with multiple tiers of shorter subgills.

Flesh

Thin and fragile; white to pale grayish; stem flesh is fibrous and may become hollow.

Spore print

White.

Partial veil

Often absent or consisting of a faint, cobweb-like (cortina) structure leaving gray hairs on the stem, typically only visible on young specimens.

Edibility

While traditionally considered edible with a mild flavor, this species is now known to cause rhabdomyolysis and contains toxins identified by researchers in 2014. It is easily confused with numerous other grey Tricholoma species of unknown or dubious safety, including the poisonous Leopard Knight (T. pardinum) which causes severe gastric upset. Identification is difficult because multiple similar species are often grouped under this name, and it should be distinguished from T. scalpturatum, which has a farinaceous odor and taste.

Nutrient Source

It forms symbiotic associations with tree roots, exchanging nutrients with the tree.

Common Names

Danish

Muse-ridderhat, Jordfarvet ridderhat

Dutch

muisgrijze ridderzwam, Muisgrijze ridderzwam

English

Grey Knight

Finnish

harmaavalmuska

French

Tricholome terreux, Petit-gris, Petit gris

German

Erd-Ritterling, Mausgrauer Erd-Ritterling

Swedish

jordmusseron, gråmusseron

Welsh

Marchog Llwyd

Synonyms

• Agaricus madreporeus
• Agaricus myomyces
• Agaricus myomyces
• Agaricus myomyces
• Agaricus pullus
• Agaricus terreus
• Cortinellus terreus
• Gymnopus myomyces
• Gyrophila terrea
• Tricholoma bisporigerum
• Tricholoma chrysites
• Tricholoma myomyces
• Tricholoma terreum
• Tricholoma terreum