Psathyrella

Description: Medium agarics, gregarious close to young oak tree.
Pileus: Broadly convex to almost flat, brown with whitish appendiculate velar remnants in young specimens, dry, smooth, hygrophanous, diameter 19-50mm.
Stipe: White, pruinose, fragile, hollow, straight but thickening slightly towards the base, 3-7mm diameter, 40-61mm height.
Gills: Adnexed, crowded, dark brown in colour.

Microscopy:
Pileipellis: Two layers - an upper layer of gelatinous globular elements with a lower layer of interwoven hyphae. Occasional large globose 'pileocystidia' seen.
Stipe: Fibrils present as interwoven hyphae terminating in filamentous caulocystidia. Clamp connections - not seen.
Cheilocystidia: Present as bundles of lageniform cystidia.
Pleurocystidia: Uncommon, enlarged rounded.
Gill trama: Regular centrally, subregular towards the gill edge.
Basidia: 2,3 and mainly 4-spored.
Spores: Ellipsoid, smooth, dark brown with small germ pore (1.1-1.4µm); L= 6.8-8.5µm, W = 3.8-4.6µm, Q=1.55-2.00, Qm=1.81