On fallen twigs or moss-covered trunks of
deciduous trees, or on fallen leaves of e. g. Salix and
stems of different herbs, such as Filipendula ulmaria. Also found on fallen
hazel nuts. Early summer to early winter. There are not many records in The
Norwegian Mycological Database, but it has probably been overlooked because of the small size and seems to be fairly common, at least in South East Norway.
Pileus 2-5 mm
across, hemispherical, conical, becoming more or less parabolical
with age, translucent-striate, shallowly sulcate, white-furfuraceous
to floccose, glabrescent, white or grey. Lamellae
7-13, not always reaching the stipe, ascending, narrowly
adnate or attached to a pseudocollarium, the edge convex,
white. Stipe 5-30 mm long,
filiform, straight to flexuous, equal, greyish-hyaline,
puberulous, glabrescent with age, but often hirsute below,
the base somewhat bulbous with a small, hirsute, white,
basal disc. Odour none.
14-18 x 7-9 µm, clavate or obpyriform, 2- spored, rarely 4-spored.
8-10.5 x 4.5-6 µm, Q = 1.5-1.9, pip-shaped, smooth, amyloid.
11-32 x 7-18 µm, clamped, clavate or obpyriform to fusiform,
mostly with a slender, straight to curved, simple or occasionally
furcate neck up to 20 µm long; smooth or
covered with warts or cylindrical excrescences 0.5-1.5 x
0.5 µm. Lamellar trama dextrinoid. Hyphae
of the pileipellis smooth to verrucose,
cells globose to obpyriform, densely covered
with warts. Caulocystidia
20-110 x 6-7 µm, lageniform to cylindrical, smooth.
Basal disc cystidia
similar to the caulocystidia but typically shorter, often
in chains of 2-4 cells, terminal cells 22-60 x 5-12 µm,
cylindrical, clavate, lageniform, obtuse to subacute, smooth
or rarely with a few coarse, apical excrescences. Clamps abundant in 2-spored form, very rare to apparently absent in 4-spored form..
Mycena tenerrima occasionally
grows on hazel nuts. Two other
species have been reported growing on hazel nuts: M.
discopus (Lév.) Quél. and M.
nucicola Huijsman. M. discopus
is a somewhat dubious species and awaits further description.
Desjardin (1995: 79) excluded it as a nomen dubium.
Huijsman (1958) described the cheilocystidia of M.
nucicola as clavate, lacking an apical
rostrum and Maas Geesteranus (1991b) did not report otherwise.
Desjardin (1995) and Robich (2003) showed, however, that
many of the cheilocystidia near the pileus margin have a
single apical projection. A Norwegian collection
showed long, flexuous rostrae as in M. tenerrima.
M. nucicola can according to Desjardin (1995) be
separated from M. tenerrima on account of the
4-spored basidia, somewhat narrower spores and presence
of acanthocysts on the basal disc.
M. tenerrima is supposed to have
the following differentiating features:
1. 2-spored basidia
2. clamp connections common in all tissues
3. spores (4.8-)5-6(-6.4) µm broad
4. caulocystidia lanceolate, smooth
5. basal disc cystidia variously shaped, shorter than the
caulocystidia, smooth or rarely with a few apical excrescences,
often in chains.
M. nucicola is supposed to have the
1. 4-spored basidia
2. clamp connections rare on tramal hyphae (absent elsewhere?)
3. spores 4.2-5 µm broad
4. caulocystidia lanceolate with a broadened base, smooth
5. basal disc cystidia of two kinds: a) acanthocysts and
b) elements similar to the caulocystidia, not in chains
The differences are rather marginal, and recent ITS sequences of collections determined as M. tenerrima and M. nucicola from Norway and Sweden indicated that the two taxa belong to the same species (Aronsen & Larsson 2015). Hence, M. nucicola should be regarded as a synonym.
One problem is connected to M. adscendens
var. carpophila (J.E. Lange) Desjardin, which seems
to be very unsufficiently known. The type does not exist. Lange reported the species as having 4-spored
basidia, narrower basidiospores, and fruits on Fagus
pericarps, but he did not report on cheilocystidia shape
nor caulocystidia, and he certainly was not aware of microscopic
features of the basal disc. Until new material can be found
it is impossible to tell anything certain about this variety.
Van den Berg et al. (2000) described the new species Mycena cecidiophila A.P. Berg, Berg-Block, Noordel. & Uljé, that was found growing on old knopper galls on the cups of Quercus robur. It differs from Mycena tenerrima in having a consistently brownish centre of the pileus and a conspicuously fimbriate margin. In addition it was characterized by the absence of pleuro- and cheilocystidia and a negative Melzer-reaction in the lamellar trama. The authors also proposed the new section Cecidiophilae to accomodate the new species. Later, this taxon has been shown to be identical with M. rhenana Maas Geest & Winterh. (Noten & Vannieuwerburgh 2009).
Sacchariferae Kühner ex Singer comprises
six species in Europe.
Further images on the Internet:
Mycologique de Strasbourg
Sociedad Micológica Errotari