Growing exclusively in moist, moss rich coniferous or mixed woods, often in large groups on the needle beds. Autumn. Widely distributed in Northern Europe but rare in some countries as Belgium, Denmark and UK, and absent in the Netherlands. Common in South Norway, but rare in the north, and not recorded in Finnmark.

Pileus 5-20 mm across, parabolical to convex, finally almost plane with a small umbo, sulcate, translucent-striate, glabrous, without or with a shallow umbo or occasionally centrally somewhat depressed, bright pink, salmon pink to brownish pink, usually darker at the centre, brownish red, sienna coloured. Lamellae 15-18 reaching the stipe, ascending to subhorizontal, ventricose, broadly adnate, somewhat decurrent, dingy pink or pale pink, minutely punctate with reddish dots (pleurocystidia), the edge bright violet red or brownish red. Odeur and taste indistinctive. Stipe 20-50 x 0.5-2 mm, hollow, terete, straight, often curved below, pruinose, glabrescent, in young specimens dark brown at the apex and paler brown below, then reddish brown, becoming pale pink, yellowish pink to pale pink brown, the base densely covered with long, coarse, flexuous, yellowish to whitish fibrils.

Basidia 25-33 x 6.5-9 µm, clavate, 4-spored. Spores 7.5-10 x 4-5 µm, Q = 1.6-2.3; Qav ~ 1.9, pip-shaped, smooth, amyloid. Cheilocystidia 25-80 x 4.5-18 µm, forming a sterile band, clavate to fusiform or more rarely somewhat irreularly shaped, with red contents, smooth or covered with few to fairly numerous, unevenly spaced, simple or more rarely furcate, cylindrical to variously inflated, straight to curved excrescences 1.5-10 x 1.5-5.5 µm. Pleurocystidia fusiform, smooth, with red contents. Lamellar trama dextrinoid, brownish vinescent in Melzer's reagent. Hyphae of the pileipellis 2.5-10 µm wide, sparsely to densely covered with warts and cylindrical excrescences 1-2.5 x 1-2 µm and partly covered with variously branched side-branches, tending to be somewhat gelatinized. Hyphae of the cortical layer of the stipe 2-4.5 µm wide, smooth to sparsely covered with cylindrical excrescences; the terminal cells inflated 5.5-12.5 µm wide, covered with warts or cylindrical excrescences. Clamp connections abundant at all tissues.

Mycena rosella is easy to identify. The pink colours, the brightly coloured lamellar edge, and the habitat are characters that make it quite unique among European Mycenas. It could probably not be mistaken for any other Mycena. White forms are known to occur (Maas Geesteranus 1986). It is a member of sect Luculentae Maas Geest. subsect. Rosellae Singer ex Maas Geest.