Mycena renati

In small groups or fasciculate on wood and fallen branches of deciduous trees, e. g. Alnus, Corylus, Fagus. Summer to autumn. Widely distributed in Norway but not common. See the records in The Norwegian Mycological Database.

Pileus up to 32 mm across, conical, parabolical, finally convex, pruinose, glabrescent, shallowly sulcate, translucent-striate, at first dark reddish brown, becoming paler reddish brown to pinkish brown, darker at the centre. Lamellae 16-20 reaching the stipe, ascending, adnate, decurrent with a short tooth, becoming dorsally intervenose with age, dingy white; the edge concolorous or reddish brown. Stipe up to 65 x 1.5 mm, hollow, straight to curved, equal, terete, pruinose, glabrescent, bright yellow, turning brown from the base with age; the base covered with white fibrils. Odour indistinctive to weakly nitrous.

Basidia 25-31 x 7-10 µm, clavate, 4-spored, clamped, with sterigmata up to 8 µm long. Spores 9.2-10.2 x 5.1-5.5 µm, fairly broadly pip-shaped, amyloid. Cheilocystidia 34-63 x 8-14 µm, forming a sterile band, fusiform, rarely lageniform or clavate, clamped. Pleurocystidia similar, if present. Lamellar trama dextrinoid. Hyphae of the pileipellis up to 12 µm wide, clamped, smooth or covered with coarse, rounded, mostly inflated excrescences. Hyphae of the cortical layer of the stipe smooth or covered with scattered rounded warts, clamped, the terminal cells coarsely diverticulate.

Mycena renati is a member of sect. Rubromarginatae Singer ex Maas Geest. although the colour of the lamellar edge often is absent or hardly noticable, or only visible near the margin of the pileus. It is easily identified because of the red-brown pileus and the bright yellow stipe. Microscopically the inflated excrescences of the hyphae of the pileipellis should be noticed as a reliable character.

M. bresadolana Robich & Neville, recently described from Italy, also has a brigth yellow stipe. It is supposed to differ from M. renati on account of a more lilac-brown pileus, subglobose spores, the hyphae of the pileipellis gelatinizing, and the hyphae of the cortical layer of the stipe smooth.