On fallen leaves of Salix. Autumn. So far Mycena terena has been reported from two localities in South East Norway.
Pileus 1-3 mm
across, conical, parabolical, campanulate, hemispherical,
young occasionally with a small papilla, later mostly umbonate,
flattening with age, rarely plano-convex and with the centre
somewhat depressed, generally shallowly sulcate, translucent-striate or not,
minutely pruinose, glabrescent, dry, at first very pale
grey or pale beige, often with the centre darker grey, fading to white, often with the centre yellowish or ochraceous
brown when drying. Flesh thin, pallid. Odour
none, taste not recorded. Lamellae
0 - 8 reaching the stipe, usually well developed (although
less than 0.5 mm broad) but occasionally only showing as
faint ridges, tender, ascending, becoming subhorizontal,
adnate to broadly adnate, smooth, white, the edge more or
less concave, white. Stipe 5-10(-23) x <0.2 mm, equal, terete, flexuous, smooth, minutely
pruinose, glabrescent, entirely black in very young specimens except
for the base which is whitish, retaining the black colour
only at the very apex when growing older, watery grey to dark grey
farther below, finally fading to greyish white or watery
white throughout, the base attached to the substratum by
shorter or longer, fine, white, shiny fibrils, but often seemingly inistituous.
17-27 x 7-10 μm, clavate, 4-spored, with plump
sterigmata 4.5-6.5 μm long. Spores
7.2-9.5 x 4.5-5.8 μm, Q 1.5 - 2.2, Qav ~ 1.8, pip-shaped, smooth, amyloid.
17-34 x 6.5-11 x 0-4.5 μm, occuring mixed with basidia
(lamellar edge heterogeneous), cylindrical, subclavate,
fusiform, sublageniform, occasionally sigmoid, smooth, rarely with a few, very coarse
excrescences, apically generally broadly rounded but also
more or less narrowed to form a neck. Pleurocystidia
absent. Lamellar trama dextrinoid, vinescent in Melzer's reagent. Hyphae
of the pileipellis 4.5-16 μm wide, densely
covered with cylindrical, straight excrescences 1-2.5 x
0.9 μm, terminal cells up to 17 μm wide, clavate, some more globose. Hyphae
of the cortical layer of the stipe 1.5-4.5
μm wide, more or less
densely covered with cylindrical, sometimes more thorn-like,
straight to curved excrescences 1-3.5 x 0.9 μm. Clamp connections present in all tissues, but clamps infrequent and easily missed.
Mycena terena is readily identified
by its occurence on fallen Salix leaves, the minute
size, the greyish-white pileus, and the black stipe (the
latter feature easily seen in young specimens, but in older
specimens it may be present only at the very apex, or may
even be entirely disappeared). It is a member of section
Polyadelphia Singer ex
Maas Geest. and has many features in common with the section's
type species, Mycena
polyadelpha (Lasch) Kühner. There is one
character, however, by which this species can at once be
separated from the other members of the section: the cheilocystidia
A similar looking, species, also growing on fallen Salix leaves and with equally smooth cheilocystidia, is the recently described Mycena guldeniana Aronsen & Perry. It can be distinguished by the the grey-brown pileus, somewhat broader spores, and occurence in alpine sites.
Quite often M. terena grows together with a tiny, white species of Marasmius. More confusion may be caused, however, by specimens of M. mirata (peck) Sacc. They may be equally white, usually growing on small twigs but also on fallen leaves of Salix, and even the black apex of the stipe may be present. A microscopic investigation, however, will readily separate the two species.
Go to key
to sect. Polyadelphia.