Psathyrella atomatoides (Peck) A.H. Sm.

Diagnosis fuente
Macroscopic characters
Pileus: 18  – 30 mm,  hemisphaerical then  conical-convex; darkish  brown  discoloring outside centre  to greyish brown and at margin to ochraceous brown; striate at margin. Veil white, appendiculate at margin and covering all pileus with fibrillose-squamulose remains. Lamellae: close, with two tiers of lamellulae, straight (not ventricose); edge hyaline. Stipe: 45 – 55 × 4  – 6 mm, cylindraceous to tapering  upwards,  brownish under a white covering of  fibrils  and small flocci. Context: without any peculiar smell; other characters not examined.
Microscopic characters
Spores: (6.0 – 8.0 × 3.3 – 4.6 µm, Q = 1.58 – 1.97, in front view elliptic to subcylindraceous or narrowly oval, in side view adaxially flattened, sometimes subamygdaliform or subphaseoliform; orangish brown with or without a weak reddish shade in water and in ammonia; germ pore absent or a callus or very small and up to 0.5 (1.0) µm broad. Basidia: 4-spored. Pleurocystidia: 35.0 – 47.0 × (9.5) 11.0 – 15.0 (17.5) µm, mostly utriform, also lageniform or conical, sometimes with  an  abruptly  tapered  apex or  subcapitate;  in  part  with  yellowish  sub  thickened  wall below  the  apex  in ammonia; moderately numerous. Cheilocystidia: similar  to pleurocystidia  but more often  lageniform to  conical, hyaline, thin-walled;  numerous but scattered towards the pileus margin; paracystidia up to 13 (30) µm broad, hyaline, thin-walled; numerous towards the pileus margin. Pileipellis: cellular. Clamp connections: present. Habitat  and  collection  studied:  France,  Nièvre,  Prémery,  forêt  domaniale  de  Prémery,Nature  Reserve  of Mardelles,  47.201033° N  3.30457°  E, 330  m. a.s.l.,  gregarious  in a  peat bog  with  Salix sp.  and  Betula sp.