Psathyrella dunarum Kits van Wav.

Diagnosis fuente: PERSOONIA - Suplement - Vol. 2 - THE DUTCH, FRENCH AND BRITISH SPECIES OF PSATHYRELLA - 1985 E. KITS VAN WAVEREN - Rijksherbarium, Leiden, The Nederlands
     Cap 15-23 mm, conico-paraboloid, spreading to convex, often with fairly distinct umbo, strongly striate, at marginal area subsulcate, greyish brown, at umbo browner, hygrophanous, drying out to pale ochre with isabelline centre, without pink, distinctly micaceous, not rugulose. Veil white, fugacious, on cap in early stages very distinct, forming a fairly dense layer of fibrils at margin and appendiculate bearded fibrillose fascicles, some of them reaching stem, forming isolated fibrils on stem. Gills 2-3 mm broad, ventricose, broadly adnate with tooth, at first greyish, finally dark purplish brown; edge white, with unmistakable red underlining (microscopical examination may be needed). Stem 20-30 x 1-2 mm, cylindrical, with slightly thickened base, white, hollow, with pruinose apex. Colour of flesh of cap and stem not recorded. Trama of ‘washed’ gill pale yellowish brown (Mu. 10 YR 7/4), slightly paler and greyer towards edge. Spore print purplish black. 
   Spores 8-9 x 4.5—5.5 ym (mean values 8.7 x 5.4 pm: 1 collection), in face view many spores distinctly ovoid, more rarely ellipsoid, in profile ellipsoid, adaxially flattened, in water orange-brown (Mu. 5 YR 5/8, 4/8), in NH,OH 10% brown (Mu. 5 YR 5/6), in KOH 5% sordid brown (Mu. 10 YR 5/3, 4/3), not opaque, with distinct germ pore (+ 1.8 um) and small hilar appendix. Basidia 17.5—22.5 x 8-10 um clavate, 4-spored. Pleurocystidia 40—52.5 x 10-12.5 um, scarce, lageniform with subobtuse apex and short pedicel thin-walled, colourless. Marginal cells: spheropedunculate and clavate cells, 12.5-30(—37.5) x 10-25 pm, abundant, densely packed, intermixed with few scattered lageniform cheilocystidia, 37.5—50 x 10-15 um; all cells thin-walled and colourless. Hymenophoral trama in NH,OH10% sub micr. distinctly be it pale yellowish brown, without yellow hyphal septa or encrustations. Pileipellis a 2—3 cells deep layer of subglobose colourless cells, 15—25 um diam.
HABITAT & DISTRIBUTION: Solitary in moss of shallow valley in coastal sand dunes.