Psathyrella impexa (Romagn.) Bon

Diagnosis fuente: PERSOONIA - Suplement - Vol. 2 - THE DUTCH, FRENCH AND BRITISH SPECIES OF PSATHYRELLA - 1985 E. KITS VAN WAVEREN - Rijksherbarium, Leiden, The Nederlands
     Cap in earliest stages 4—7 mm, conico-paraboloid, warm reddish brown (Mu. 5 YR 3/4) but very soon warm brown (Mu. 7.5 YR 4/4), then rapidly fairly dark greyish brown (Mu. 10 YR 4/2), centre remaining browner, ochre brown, at maturity 15-35 mm, spreading via paraboloid to convex, dark greyish brown (Mu. 10 YR 3/2, 3/3, 4/3), greyer towards margin (Mu. 10 YR 4/2, 5/2), striate up to 1/2-3/4 from margin, hygrophanous, young caps drying out to pale yellowish brown (Mu. 10 YR 7/4), mature caps to pale greyish brown (Mu. 10 YR 6/3) with a conspicuous pink to pinkish vinaceous colour, resulting in a rosy or flesh colour (Mu. 5 YR 6/2, 6/3, 5/2, 5/3, 8/2, 7/3) of 2/3 of cap, contrasting sharply with pale brown or yellowish ochre (Mu. 10 YR 7/4, 7/6, 6/4, 8/3, 8/4, 8/6) centre, distinctly micaceous and rugulose or sulcate. Veil strongly developed, in young stages on cap forming a lanose coating, covering entire cap with adpressed fibrils, flocci and small scales with at margin appendiculate fibrils and fascicles of fibrils, on stem forming a lanose coating, at maturity still many fibrils and fascicles, sometimes also flocci in marginal zone of cap and on stem. Gills 3-5 mm broad, rounded near margin, then ascending, straight or subventricose, broadly adnate, often with decurrent tooth, dark greyish (Mu. 10 YR 5/1) to greyish brown, near edge with a trace of purple (Mu. 10 YR 5/2; 7.5 YR 6/2), darker (Mu. 10 YR 4/1, 4/2) towards base, with white edge. Stem 30-55(—75) x 2-3 mm, cylindrical, sometimes distinctly flexuous, fragile, hollow, white but isabelline below, with pruinose apex. Flesh of cap in centre 1-2 mm thick, dark greyish brown (Mu. 10 YR 3/2, 3/3), of stem white. Trama of ‘washed’ gill near base very pale brown (Mu. 10 YR 7/4, 7/3), paler and greyer towards edge, very pale near edge, in early stages yellowish brown (Mu. 10 YR 6/4, 6/6) near base. Spore print purplish black. ;
     Spores 8-10 x (4~-)4.5—5.5 pm (mean values 8.3~-9.3 x 4.7-5.3 um: 4 collections), ellipsoid, adaxially flattened, dark, in water dark red (Mu. 10 R 3/4; 2.5 YR3/4), in NH,OH10% dark reddish brown (Mu. 2.5 YR 2.5/4), in KOH 5% dark sordid brown (Mu. 10 YR3/2; 7.5 YR 3/2), with distinct germ pore (1.5—1.8 ym) and distinct hilar appendix. Basidia16—25.5 x 8—9.5 um, clavate, 4-spored, Pleurocystidia 35~55(—60) x 10—17.5 um, moderately to fairly numerous, fusoid, sometimes drawn out into a short neck, tapering towards obtuse to subacute apex, with fairly short pedicel, thin-walled, colourless. Marginal cells: pleurocystidioid cheilocystidia 20—45 x 7.5-15 um, numerous to abundant, often without distinct pedicel, intermixed with variable quantities but usually numerous unobtrusive small spheropedunculate and clavate cells, 10-20 x 7.5—10 pm; all cells thin-walled, but sometimes larger spheropedunculate cells slightly thick-walled, and colourless. Hymenophoral trama in NH,OH 10% sub micr. in basal area pale brown from membranal pigment with a few yellow hyphal septa, towards edge much paler, without encrustations. Pileipellis a 3-4 cells deep layer of subglobose cells, 25-50 pm diam., very pale brown in NH,OH 10%.
HABITAT & DISTRIBUTION. — Terrestrial, solitary or gregarious, on verges of roads in Quercus and Fagus woods.