Russet toughshank or Butter cap

Cap 2-6 cm, hemispherical at first, then convex-spreading to flat. The color varies — from russet-yellow to yellow-brown, darker in the center and paler toward the edge. In dry weather the cap fades to cream. The surface is smooth and slightly shiny in wet weather.

Cap 3-7 cm across, when young convex, becoming with age flat-expanded with a small umbo in the center (a characteristic shape). Cap skin smooth, with a pronounced buttery-greasy sheen in wet weather — hence the name. Strongly hygrophanous: in wet weather — dark chestnut-brown in the center, lighter toward the margin; when dry — light creamy brown, ochre and faded. The margin is even, thin, often with lengthwise striations where the gills show through.

Gilled hymenophore. Gills crowded, thin, attached or notched. Whitish to cream. Spore print white.

Gilled hymenophore — the gills are adnate or free from the stem, crowded, thin, whitish to cream, turning cream-pink with age. Spore print pale pink to cream — a typical trait of the genus Rhodocollybia ("pink Collybia").

Stem 3-8 cm tall, 0.3-0.7 cm thick, thin, cylindrical, often curved; the lower part is darker, reddish brown, the upper part paler. The surface is smooth, the inside hollow. There is no ring.

Stem 3-7 cm tall, 0.3-0.8 cm thick, cylindrical, noticeably thickening toward the base (often with a characteristic "root-like" extension into the substrate). Color ochre-brownish, darker toward the base. Surface smooth, with lengthwise fibers. The stem flesh is tougher and more fibrous than the cap's.

The flesh of the cap is thin, whitish, with no particular aroma. In the stem it is stringy and springy. It doesn't change color when cut.

Flesh thin and tender in the cap, tough and fibrous in the stem. Color whitish to cream. Doesn't change color when cut. Smell faintly mushroomy, taste mild, neutral, normally without bitterness.

Faint, pleasant mushroomy smell. Mild taste, nothing special.

Faint, neutral, mushroomy, nothing distinctive.