Among grass and herbs and vegetable debris such as Picea and Pinus needles. Autumn. Very rare or overlooked. 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, 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 confused
with M. tristis is Mycena
aetites. Ludwig (2012) suggested that they are conspecific, and admittedly they seem to be very close. M. aetites, however, differs
in a lubricous pileus when moist, fewer lamellae, more pronounced ornamentation of the hyphae of the stipitipellis, and hyphae of the pileipellis tending to become gelatinized. Only one Finnish sequnce of M. tristis is available in GenBank (MW540723). It is 100% indentical with one Norwegian sequence of M. aetites (NOBAS2748-16) and 98.88-99.84% with two other Norwegian sequences.
Mycena ustalis
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
is 4-spored with or without 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. |
