Growing terrestrial among grass and fallen
leaves under Salix.
Pileus up to 20
mm across, conical to convex, flattening with age, mostly
with a prominent umbo, translucent-striate, sulcate, hygrophanous,
fairly dark grey with a darker, greyish brown to almost
black centre, the margin paler to whitish. Odour
nitrous. Taste not recorded. Lamellae
26-30 reaching the stipe, ascending, narrowly adnate, with
or without a short decurrent tooth, somewhat intervenose
with age, grey to dark grey, the edge convex, paler. Stipe
up to 50 x 3 mm, straight to somewhat curved, terete, hollow,
glabrous (at least in older specimens), pale grey at the
apex, darker greyish downwards, paler than the pileus, the
base densely covered with long, coarse, flexuous, whitish
29-35 x 8-9 µm, clavate, 4-spored, clampless, with
plump sterigmata 9-12 µm long. Spores
9.3-11(-12.5) x 5-6.5 µm, Qav ~ 1.8, pip-shaped, smooth,
50-103 x 13-24 x 3.5-6.5 µm, clampless, occuring mixed
with the basidia, fusiform, smooth. Pleurocystidia numerous,
similar. Lamellar trama brownish vinescent in Melzer's reagent.
Hyphae of the pileipellis
2.7-6.3 µm wide, clampless, covered with simple to
very much branched excrescences 2.5-22.5 x 2 µm which
tend to become covered with gelatinous matter; terminal
cells 45-70 x 12.5-24 µm, variously
shaped, subcylindrical, fusiform, clavate, frequently covered
with coarse excrescences 4.5-11 x 2.5 µm. Hyphae
of the cortical layer of the stipe 1.8-2.5
µm wide, clampless, smooth to sparsely covered with simple,
cylindrical excrescences 1.8-4.5 x 1.8-2.5 µm; terminal
cells (caulocystidia) 2.5-10 µm
wide, with few to fairly numerous, coarse excrescences.
Mycena austera is a member of sect.
Fragilipedes (Fr.) Quél. where it keys out
close to the American species M. deceptor Maas
Geest. (Maas Geesteranus, 1992). In the latter, however, the
pileus is smaller and pale vinaceous brown, dingy brown
or greyish brown, 14-22 lamellae are reaching the stipe,
the lamellae are whitish, and the odour is indistinctive.
In addition the conspicuous, variously shaped terminal cells
of the hyphae of the pileipellis in M. austera
will separate the two species.
Among the Norwegian species M. austera
macroscopically can be mistaken for M.
leptocephala (Pers.) Gillet, but it can be
told apart from that species on account of the absence of
clamp connections, the terminal
cells of the pileipellis, and the differently shaped
It is probably a rare species in Norway, but
it may have been confused with other nitrous-smelling species
of the section. So far only two collections are known.
Torød, 4 Nov. 1991, A. Aronsen A 16b/91; 5 Nov. 1991,
A. Aronsen A 17/91; holotype (O, no. O-F72674), Akershus, Rælingen, Teigen, 13 Oct. 2013, leg. Jørn Langbråten (O)