Grey knight or Soapy knight

Cap 3-8 cm across, when young distinctly conical or bell-shaped, becoming with age flat-conical with a low, broad central bump. The skin is finely fibrous-felty — like a mouse's fur, gray to dark gray, mouse-colored, with a darker center and paler margins. Old fruiting bodies have fine radial cracks. The margin is even and thin, and may be slightly wavy in damp conditions.

Cap 5-12 cm across, when young convex with an inrolled margin, becoming with age flattened-expanded with a small bump. The skin is smooth, slightly slimy in wet weather, dry and matte in dry weather. Color: very variable — gray-white, olive-gray, greenish-gray, brownish-gray, in some forms almost black in the center. Old fruiting bodies have small cracks.

Gilled hymenophore — the gills are notched (sinuate) where they attach to the stem, moderately crowded, thin, the gill flesh brittle. Color: whitish to grayish-white, turning gray with a faint yellowish tinge with age. Spore print white.

Gilled hymenophore — the gills are notched (sinuate) where they attach to the stem, moderately crowded, fleshy. When young they are whitish, becoming with age creamy-grayish, often turning pink when damaged. Spore print white.

Stem 3-7 cm tall, 0.7-1.5 cm thick, cylindrical, firm when young, hollow when old. Color: white to grayish-white, with no noticeable spots. Surface smooth with fine lengthwise fibers. No ring.

Stem 5-10 cm tall, 1-2.5 cm thick, firm, cylindrical, thickening toward the base when young. Color: whitish to grayish; pinkish-red spots often appear when damaged — a diagnostic feature. Surface smooth with lengthwise fibers. No ring.

Flesh thin, brittle, white in the cap, grayish-white in the stem. Does not change color when cut. Smell faintly mealy or with a fresh cucumber note, taste mild, no bitterness.

Flesh firm, white, develops pinkish-red spots when cut or pressed, especially in the lower part of the stem — a characteristic reaction and an important diagnostic. Smell distinctly soapy (laundry soap), taste soapy-bitterish, unpleasant.

Faintly mealy-cucumber, neutral, with no sharp notes.

Distinctly soapy — reminiscent of laundry or toilet soap. A diagnostic feature, especially clear when cut and in mature fruiting bodies.