Psathyrella ridicula 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 8-20 mm, paraboloid to very slightly umbonate, not or scarcely spreading, dark reddish brown (Mu. 5 YR 3/3) or dark brown with a trace of red (Mu. 7.5 YR 3/2) then dark brown (Mu 7.5 YR 4/2), strongly striate up to 1/2-2/3 from margin, hygrophanous, drying out via greyish brown (Mu. 10 YR 5/2) to pale greyish brown or grey (Mu. 10 YR 6/2, 7/2), alutaceous, at centre remaining yellowish brown (Mu. 10 YR 7/4, 8/6), without pink, slightly micaceous, rugulose. Veil on cap very fugacious but stem in its lower 1/2-2/3 conspicuously covered with white velar fibrils, fascicles of fibrils and even adpressend flocci. Gills 2-3 mm broad, slightly ventricose near margin of cap, then straight, ascending, broadly adnate, at first greyish (Mu. 10 YR 4/1) with a trace of purple or brown, at maturity dark purple with a greyish tinge (Mu. 5 YR 3/2), brownish (Mu. 10 YR 3/2, 3/3) near base, with white edge. Stem 30—60 x 1-2 mm, straight, cylindrical, rooting (pseudorrhiza 5S—15 mm), in upper part white, lower down isabelline, pale brown at base (white velar remnants contrasting with brownish colour). Flesh of cap in centre 1.5—2.5 mm thick, dark greyish brown, of stem white. Trama of ‘washed’ gill in NH,OH 10% under binocular lens distinctly brown (Mu. 10 YR 6/3, 7/3) in basal 1/2-2/3, still pale brown near edge. Spore print purplish black
   Spores 11.5-13.5 x 6.5—7 ym (mean values 12.2 x 6.5 um: 1 collection), in water red(Mu. 2.5 YR 3/6) in NH,OH 10% dark brown (Mu. 5 YR 4&3) in KOH 5% sordid Brown (Mu. 10 YR 4/3, 3/3), opaque, with distinct germ pore (+ 2 ym) and small hilar appendix. Basidia 20-32 x 9.5-12.5 ym, 4-spored. Pleurocystidia 40-60 x 7.5-14 (—17.5) pm, moderately numerous, sublageniform, many with slightly swollen apices, thin-walled, colourless. Marginal cells: pleurocystidioid cheilocystidia 30-45 x 6-10 um, varying from locally fairly crowded to scattered, intermixed with spheropedunculate and clavate cells, 15-20 x 7,5—12.5 um in varying numbers; all cells thin-walled, colourless. Hymenophoral trama in NH,OH 10% sub micr. distinctly brownish from membranal pigment at base, gradually paler towards edge, with many yellow hyphal septa and encrustations in basal part. Pileipellisa 2-3 cells deep layer of subglobose colourless cells, 16-32 ym diam.
HABITAT & DISTRIBUTION. — Solitary and subcaespitose around stump of Fagus in sandy soil (dunes).