Mycena viridimarginata P. Karst.

Hedwigia 31: 218 (1892)

© A. Aronsen
VESTFOLD, Tønsberg, Syrrebekk 19 July 2004

Growing on fallen branches or decaying stumps of coniferous trees. Sometimes also on wood of broad-leaved trees. Summer to autumn. A rather common species in the boreal zone but very rare in the lowlands with no records from Denmark, a few from the Netherlands and one from the UK (Aronsen & Læssøe 2016). Fairly common in coniferous forest in Norway.

Pileus 10-40 mm across, conical, campanulate, flattening with age, without or with a low umbo, pruinose, glabrescent, hygrophanous, sulcate, translucent-striate, reddish brown, olivaceous brown, greenish brown, olive green, greyish green, the margin paler, yellowish olive, greenish yellow, or more greenish. Lamellae 20-25 reaching the stipe, ascending, narrowly adnate to adnate, occasionally decurrent with at short tooth, whitish, greyish white, yellowish white to grey, the edge olivaceous or greenish grey, dark grey to dark grey-brown, often only near the margin of the pileus, and sometimes not differently coloured at all. Stipe 20-70 x 1-3 mm, hollow, fragile, equal or somewhat widened below, terete, straight to curved, pruinose above, glabrous farther below, yellowish to yellowish brown (honey-coloured), darker to dark brown towards the base, the apex sometimes very pale, almost white, the base densely covered with whitish fibrils. Odour indistinctive to weakly nitrous. Taste slightly raphanoid.

Basidia 25-32 x 8-10 µm, slender-clavate, 4-spored, with sterigmata 5-8 µm long. Spores 9-11.8(-13) x 6-7.5 µm, Q 1.3-1.7, Qav ≈ 1.5, broadly pip-shaped, amyloid. Cheilocystidia 23-70 x 7-18(-29) µm, forming a sterile band, clavate, fusiform, subcylindrical, apically obtuse or mucronate or narrowed into a simple neck or two necks. Pleurocystidia not observed. Hyphae of the pileipellis 2-8 µm wide, not gelatinized, covered with simple or branched cylindrical to more irregularly shaped excrescences 2-20 x 1.5-6 µm wich may form dense masses. Hyphae of the cortical layer of the stipe 1.5-4 µm wide, slightly gelatinized, smooth or sparsely covered with obtuse warts or short cylindrical excrescences 1-6(-12) x 2-3.5 µm, terminal cells with coarse cylindrical to clavate excrescences. Clamp connections present at all tissues.

More micro drawings.

Microphotos of cheilocystidia

Microphotos of pileipellis

Microphotos of caulocystidia and stipitipellis

Maas Geesteranus (1988) placed this species in section Fragilipedes together with Mycena citrinomarginata, both species formerly placed in sect. Rubromarginatae. The coloured gill edge indicates a close relationship to the species of sect. Rubromarginatae, but in the sense of Maas Geesteranus that section contains only species with the gill edge coloured pink, reddish brown or violet. Besides, the edge is not always coloured or just partly so in M. viridimarginata.

In some collections there are no traces of different colour at the gill edge, and in some other collections the colour is visible only very near the margin of the pileus.

It is, however, often more visible in younger specimens. Generally the colour of the lamellar edge is the same as in the margin of the pileus.

Mycena viridimarginata is a very variable species. The identification rarely causes any difficulties, however. The yellowish or honey-coloured stipe combined with the olive-brown or greenish colours on the pileus are typical characters.

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© A. Aronsen 2004


© Arne Aronsen 2002-2023