Psathyrella fusca (J.E. Lange) A. Pearson

Diagnosis fuente: http://PERSOONIA - Suplement - Vol. 2 - THE DUTCH, FRENCH AND BRITISH SPECIES OF PSATHYRELLA - 1985 E. KITS VAN WAVEREN - Rijksherbarium, Leiden, The Nederlands
Cap 15-50 mm broad, conical or conicé-paraboloid, later conico-convex, with margin in
young stages not or only slightly incurved, very dark brown (Mu. 7.5 YR 3/2, 4/2; 10 YR
4/3), bronze brown or (usually) warm ochre brown (Mu. 7.5 YR 4/4; 10 YR 4/4), paler and
often somewhat greyer towards margin, striate up to 3/4 from margin, hygrophanous, drying
out to pale or very pale brown (Mu. 10 YR 6/3, 7/3), alutaceous or even whitish (Mu. 2.5 Y
8/2), often distinctly or only very slightly mixed with pink, at centre ochre or yellowish,
usually slightly micaceous and more or Jess rugulose. Veil under favourable circumstances
distinct but fugacious, forming on cap many to numerous isolated very small arachnoid,
stellate wicker-works or bundles of fibrils in a 3-5 mm broad zone along margin, rarely
stronger developed and even appendiculate, on stem scattered fibrils and sometimes minute
flocci. Gills 3~6 mm broad, somewhat ventricose or straight, ascending, not crowded,
broadly adnate, in young stages purplish grey (Mu. 5 YR 4/1), at maturity overall colour
dark greyish brown-purple, near edge purplish grey (Mu. 5 YR 4/1, 5/2), towards base
greyish brown (Mu. 10 YR 5/2, 4/2, 3/2; 7.5 YR 3/2) with purplish (violaceous) hue (5 YR
4/2), near base slightly browner; with whitish or concolorous edge. Stem (30—)50—90 x 2-4
(apex) to 47 (extreme base), cylindrical but sometimes slightly thickening towards base,
snow-white, polished, flamed, rarely slightly isabelline below, hollow, with pruinose apex
and non-rooting sometimes subbulbous and distinctly strigose base. Flesh in cap 1-3 mm
thick, dark brown (Mu. 10 YR 4/4, 4/3, 3/3), in stem white or whitish, sometimes very pale
brown below. Trama of ‘washed’ gill pale brown or greyish brown (Mu. 10 YR 6/2, 6/3, 7/3),
near base with a trace of yellow (Mu. 10 YR 7/4); edge sometimes brown (see below). Spore
print purplish black.
Spores 7~9 x 4-5 um (mean values 7.5~8.4 x 4.5-—4.7 pm: 8 collections); ellipsoid,
adaxially flattened, in water dark orange-brown (Mu. 5 YR 4/4, 4/6, 4/8) in NH,OH 10%
dark brown (Mu. 7.5 YR 4/4), in KOH 5% dark sordid brown (Mu. 10 YR 4/3, 3/3), not
opaque, with distinct germ pore (+ 1.5 4m) and small hilar appendix. Basidia 14—20 x 7.5—9
um, clavate, 4-spored. Pleurocystidia 30-50(—55) x 10-15(—17.5) um, moderately numerous
(rarely very scarce or very numerous), utriform to subutriform, pedicellate, with obtuse
apex, practically colourless (or very pale brown in NH,OH 10% ). Marginal cells: Pleurocystidioid
cheilocystidia 20-35 x 7.5—12.5(—15) um, moderately numerous to abundant,
intermixed with sometimes few, but usually numerous small spheropedunculate and clavate
cells, 10-20 x 7.5-12.5 um and a few larger and often slightly thick-walled spheropedunculate
cells, 15-30 x 12.5—-20 um, often some or many more or less distinctly brown in
NH,OH 10% and in such cases the subhymenial cells at edge also yellowish brown.
Hymenophoral trama in NH,OH 10% sub micr. very to distinctly pale brown from membranal
pigment, with few yellow hyphal septa, sometimes with numerous minute encrustations.
Pileipellis a 2—4 cells deep layer of colourless cells, 25-40 ym diam.
HABITAT & DISTRIBUTION. — Terrestrial or attached to pieces of wood in the ground;
under Fagus. Aug.-Oct. Rare in the Netherlands. Reported from France and the British
Isles.