Mycena hiemalis (Osbeck) Quél.

Mém. Soc. Émul. Montbéliard, Sér. 2, 5: 110 (1872)

= Phloeomana hiemalis (Osbeck) Redhead
in Index Fungorum no. 289 (2016)

© A. Aronsen
VESTFOLD, Tjøme, Hvasser, Sønstegård 29 Nov. 2003.

On moss-covered trunks of deciduous trees, e. g. Fagus, Salix, Ulmus. Summer to winter. Records in The Norwegian Mycology Database.

Pileus 2-10 mm across, campanulate, conical, sometimes becoming convex to applanate, with or without a small papilla, shallowly sulcate, translucent-striate, glabrescent, very variable in colours, fairly dark brown with the centre blackish brown, turning paler brown with age or at first pale grey-brown and dark brown at the centre, paler with age, becoming very pale brown to beige, mostly darker at the centre, sometimes entirely white, the margin usually white. Lamellae 8-14 reaching the stipe, ascending, narrowly to more broadly adnate, pale grey to white. Stipe 10-35 x 0.5-1 mm, hollow, curved, terete, equal, pruinose or minutely puberulous, glabrescent except for a pruinose apex, white, occasionally yellowish towards the base with age, the base covered with long, coarse, flexuous white fibrils. Odour indistinctive.

Basidia 25-35 x 6-7 µm, clavate, 2-spored, clampless (4-spored, clamped specimens may occur). Spores 7-9.5 x 5.2-7 µm, Q = 1.1-1.5, Qav ~ 1.3, broadly pip-shaped, smooth, non-amyloid. Cheilocystidia 30-55 x 9-15 µm, forming a sterile band, clamped or clampless, fusiform to utriform, smooth, usually broadly rounded. Pleurocystidia similar, if present. Lamellar trama weakly reddish brown in Melzer's reagent. Hyphae of the pileipellis 2-4 µm wide, sparsely diverticulate, covered with usually simple, more rarely furcate, cylindrical, straight to curved excrescences 2-9 x 1-3 µm. Hyphae of the cortical layer of the stipe 2-6 µm wide, smooth, terminal cells (caulocystidia) 12-55(-64) x 4-24 µm, variously shaped, generally inflated.

Microphotos of cheilocystidia, pileipellis and caulocystidia

Mycena hiemalis is a member of sect. Hiemales Konrad & Maubl. Usually it can be recognized by the growth on moss-covered trunks of deciduous trees, the usually pale pileus generally with a brownish centre, and the ascending, narrowly adnate lamellae. It can, however, sometimes be confused with M. alba (Bres.) Kühner. or with M. olida Bres. M. alba can be distinguished by the hyphae of the pileipellis that are covered with scattered, coarse, inflated, simple or broadly lobed excrescences, and by the globose spores. M. olida differs in having a whitish pileus with a yellowish centre, smooth hyphae of the pileipellis and somewhat differently shaped cheilocystidia. Dark brown specimens of M. hiemalis can be confused with M. erubescens, but the latter is easily separated microscopically.

Next image 2



Further images on the Internet:

JJ Wuilbaut 1

JJ Wuilbaut 2

Jean-Louis Cheype


© Arne Aronsen 2002-2017