Gregarious among needles under Juniperus communis. Autumn. In Norway not found outside the type locality. Robich (2003: 277-280) reported it from Italy. Recently it has also been recorded from Denmark.

Pileus 7-15 mm across, parabolical, at first pruinose, glabrescent, sulcate, translucent-striate, grey. Odour indistinctive. Taste not recorded. Lamellae 17-22 reaching the stipe, ascending, narrowy adnate with a short tooth, grey with white edge. Stipe up to 60 x 1,5 mm, straight, terete, hollow, glabrous, apically pale grey, grey-brown below, the base covered with long, coarse, flexuous, whitish fibrils.

Basidia 20-27 x 7-9 µm, clavate, 4-spored, with sterigmata c. 7 µm long. Spores 7-9(-10) x 4.3-6 µm, Q 1.3-1.8, Qav ~ 1.6, pip-shaped, smooth, amyloid. Cheilocystidia 31-68 x 9-16 x 2.5-5 µm, forming a sterile band, lageniform, rarely clavate, smooth. Pleurocystidia similar, not numerous. Lamellar trama dextrinoid, brownish vinescent in Melzer's reagent. Hyphae of the pileipellis 1.5-4.5 µm wide, not very densely covered with cylindrical, curved to flexuous, simple but very occasionally forked, excrescences 2-20 x 0.9-2.2 µm. Hyphae of the cortical layer of the stipe 1.6-3.5 µm wide, smooth, terminal cells scarce, 45-65 x 5.5-7 µm, clavate. Clamp connections present at all tissues (but clamps sometimes hard to detect).

Microphotos of the hyphae of the pileipellis

Microphotos of pileipellis and cheilocystidia

Mycena parca is a member of the large and complex section Fragilipedes (Fr.) Quél. It is closely related to the widely distributed species Mycena leptocephala, from which it can be distinguished only by a close microscopic examination. The type is described as a non-smelling, grey species. That was possibly influenced by dry weather. It can be separated from M. leptocephala by the stipe, which is conspicuously glabrous, large, lageniform cheilocystidia which are rarely seen in M. leptocephala, unbranched hyphae of the pileipellis with no tendency to be gelatinized, and the terminal cells of the stipitipellis, which are scarce and fairly narrow.

Aronsen & Læssøe (2016) showed a photo of M. parca and provided a somewhat more comprehensive description. That was an error based on some misidentified collections that have proved to represent a different species. At present, there is no photo of M. parca available.