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Mycena tristis Maas Geest.

Persoonia 13 (4): 471-473 (1988)

© K. Kokkonen 2004

FINLAND, Pohjois-Karjala, Nurmes commune 25 Sept. 2004

Among grass and herbs and vegetable debris such as Picea and Pinus needles. Autumn. So far only known from Finland.

Pileus 8–35(-45) mm across, conical to obtusely conical, translucent-striate at the margin, sometimes shallowly sulcate, pruinose, strongly hygrophanous, blackish to dark grey, becoming grey brown to pale grey when dry. Lamellae 21-c.30 reaching the stipe, ascending, up to 3.5 mm broad, narrowly adnate, sometimes decurrent with a short tooth, dorsally intervenose with age, dark grey to grey, with paler to whitish edge. Stipe 30-55(-80) x 1.5-5 mm, hollow, fragile, equal or somewhat widened towards the base, terete or somewhat compressed, straight to slightly curved, the apex slightly pruinose, glabrous below, blackish, drying to grey-brown; the base covered with white fibrils. Odour and taste indistinctive.

Basidia 30-40 x 8-9(-13) µm, clavate, 4-spored, with sterigmata 5-10 µm long. Spores 9-11.5(-13) x 6-7.5(-9) µm, Q = 1.4-2, Qav = 1.6, pip-shaped to broadly pip-shaped, smooth, amyloid. Cheilocystidia 25-70 x 10-29 µm, occuring mixed with basidia, or in parts of the lamella presumably forming a sterile band, clavate, smooth or apically covered with fairly few to more numerous, unevenly spaced, coarse, simple to furcate or branched, straight to somewhat curved, cylindrical excrescences 5-30 x 1.5-3 µm. Pleurocystidia absent or very scarce. Hyphae of the pileipellis 1-4.5 µm wide, diverticulate, covered with simple to branched excrescences 2-25 x 1-2 µm, which tend to form dense masses, not gelatinized. Hyphae of the cortical layer of the stipe 1-2 µm wide, smooth to sparsely diverticulate; terminal cells covered with simple, short, cylindrical excrescences. Clamp connections present in all tissues.

Microphotos of cheilocystidia 1

Microphotos of cheilocystidia 2

Microphotos of spores

Collections examined: FINLAND, Pohjois-Karjala, Nurmes commune, Puu-Nurmes, town, fire alley, on heath and needle litter of Pinus sylvestris. Grid 27°E: 7051:606
3 Oct. 2003 Katri Kokkonen 889/03 (TUR) and 25 Sept. 2004 Katri Kokkonen 325/04 (TUR).

See map with the Finnish collections plotted in.
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The macroscopic description above is based on the type and collector’s notes to two additional Finnish collections, my own observations on the dried material and the colour photo. The microscopic details are based on examination of the two collections kindly put to my disposal by the collector.

The dark colours of the pileus and the lamellae remind of young specimens of Mycena leptocephala (Pers.) Gillet, but the latter differs among other features in the fewer lamellae, the nitrous smell, and the smooth hyphae of the cortical layer of the stipe with their strikingly inflated terminal cells.

Another dark species that could be mixed with M. tristis is Mycena aetites (Fr.) Quél., but the latter differs in the lubricous pileus when moist, fewer lamellae, and the more pronounced ornamentation of the hyphae of the cortical layer of the stipe.

Mycena ustalis Aronsen & Maas Geest. is easily distinguished on acount of the smooth hyphae of the pileipellis and the cortical layer of the stipe; pleurocystidia are present, and the caulocystidia are numerous, more or less clavate, and smooth. Mycena austera Aronsen is 4-spored but devoid of clamps; it has differently shaped cheilocystidia, and pleurocystidia are present. Besides it is characterized by the large variously shaped, inflated terminal cells of the pileipellis.

 

© Arne Aronsen 2002-2015