Russula integra or Humpback brittlegill

Cap 6-15 cm across, when young hemispherical, with age becoming flat and spread out with a slightly depressed center. The skin is smooth, slimy in wet weather, dry and matte in dry weather, peels easily over 2/3 of the cap toward the center. Color: dark purple, chestnut-purple, wine-red, with a darker center and lighter margin. In mature specimens the margin has fine radial grooves resembling coarse ribbing.

Cap 3-8 cm across, when young conical-convex with a sharp papillate bump in the center — a diagnostic feature. With age it becomes flat-convex, but the bump remains. The cap skin is smooth, slimy and sticky in wet weather, dry and matte in dry weather, peels 1/3 of the way to the center. Color dark violet, violet-azure, purple-chestnut, richer in the center, paler toward the edge, fading to grayish. In mature caps the edge has fine radial grooves.

Gilled hymenophore — the gills are attached or free from the stem, moderately spaced, fleshy, brittle. Color when young: whitish, with age turning ochre-cream to yellowish from the ripe yellow-ochre spores. Spore print yellow-ochre — a diagnostic feature (distinguishes it from the rusty brown of webcaps).

Gilled hymenophore — the gills are attached or free from the stem, moderately crowded, fleshy, brittle. Color whitish at first, becoming cream-ochre-yellowish with age because of the mature spore powder. Spore print yellow-ochre — a diagnostic feature.

Stem 4-8 cm tall, 1.5-3 cm thick, firm, fleshy, cylindrical, hollow inside in old specimens. Color: white to creamy white, with a faint yellowish tint when old, browning toward the base. Surface smooth with fine lengthwise wrinkles. No ring.

Stem 4-8 cm tall, 1-2 cm thick, firm, cylindrical, hollow inside in old specimens. Color whitish, often with a faint violet-pink tint in the lower part. Surface smooth with fine lengthwise wrinkles. No ring.

Flesh firm, brittle, white; where cut, it slowly turns yellow (a reaction typical of the genus Russula). Smell pleasantly mushroomy, with a fruity note in mature specimens, taste mild, sweetish and nutty, with no bitterness or acridity — a diagnostic feature.

Flesh firm, brittle, white, where cut it slowly turns yellow. Smell faint and pleasant, with a hint of coconut and fruit in young specimens, taste mild and slightly bitter, especially in the stem — not burning-acrid (this sets it apart from its poisonous relatives).

Pleasantly fruity-mushroomy, with no sharp notes.

A faint, pleasant fruity-coconut smell in young specimens, neutral with age.