Rhodocollybia butyracea - Hat with a diameter of 40 to 70 mm, initially arched, then flat with a hump, very water-absorbent (hygrophanous), smooth, naked; in the moist period dark-gray, rusty-brown to red-brown, in the dry period gray-white to pale-yellow; the hump and the edge of the hat are darker than the rest. Oily and shiny surface; the edge is sharp and finely polished.

Lamellae medium, soft, rounded or notched with the tip, only attached at the top and therefore almost as free, whitish to watery white, corrugated blades.

Stem 40-80 mm high, 7- 15 mm thick, clearly conicially extending downwards, in the lower part it is sometimes thickened, initially full, with loose mycelium, later empty, fibrous, with age bare, surface longitudinally serrated, under the hat whitish , elsewhere gray-brown, rusty-brown, red-brown, at the base pellucid-white.

Flesh thin, watery, soft, elastic, in cartilaginous body, in brown wet period, in the dry period whitish; has a faint, mild taste and smell of old butter, fruity.

Occurrence: In deciduous and coniferous forests, from summer to autumn. Isolated or gregarious, common. Mostly on acidic soils.

Value: edible.