Blackening brittlegill or Milk-white brittlegill

Cap 8-20 cm across; in young mushrooms hemispherical to flat with an inrolled margin, later becoming funnel-shaped. Color white when young, turning dirty gray, ash-gray, then blackish to anthracite black with age. The cap darkens when pressed — unevenly in young specimens. Surface smooth, slightly sticky in wet weather.

Cap 5-20 cm across (often very large), convex-flat with a distinctly inrolled margin when young, with age becoming deeply funnel-shaped. The skin is matte white with an ochre-brown center; in adult specimens with noticeable bits of soil and moss stuck to it (because of the funnel shape). Base color white to cream, ochre-brown to brownish in the center. The skin is peels only at the margin, not easily. The margin is even, with a fine felty down when young.

Gilled hymenophore — the gills are attached to the stem, distant and thick, typical of the genus Russula. In young mushrooms — whitish, when damaged they redden to brownish-black, darkening with age to gray, then black. Spore print white.

Gilled hymenophore — the gills are decurrent, moderately spaced, fleshy, brittle. Color: whitish to creamy white, in the upper part, near the stem, often with a characteristic greenish-bluish tint — a diagnostic feature. Spore print white to creamy white.

Stem 4-8 cm tall, 2-4 cm thick, thick, fleshy, cylindrical, relatively short. Color white when young, turning gray, then blackish with age. Surface smooth. No ring.

Stem 2-5 cm tall, 2-4 cm thick — very short and thick, even when the cap is large. Cylindrical to conical, thickening toward the base. Color: whitish, in the upper part, with a characteristic greenish-bluish tint, with fine crosswise wrinkled grooves. No ring.

Flesh firm, fleshy, white when young. When cut, a two-phase reaction slowly unfolds (over 5-10 min): first it reddens to wine-red or bright carmine, then after a few more minutes it blackens to anthracite black. This is the classic diagnostic feature of the species. Faint mushroomy smell.

Flesh very firm, fleshy, white, brittle. Exudes no milk when damaged (it's not a milk cap!). When cut, it slowly takes on a yellowish tint. Smell faintly mushroomy, with a fruity note in young specimens, taste mild at first, then distinctly burning and acrid (especially in the gills). Boiling removes the acridity.

Faint, pleasant, mushroomy, with no distinctive notes.

Faintly mushroomy with a fruity note in young specimens, nothing striking.