HRL3539

Found in beech forest on well-decayed wood covered with decaying leaves on Sept. 26, 2021. There were about one hundred specimens.

Pileus 11-25 mm
Stipe 62-117 x 1,5-3 µm.
Partial veil cortinoid, evanescent.

Spores 11.2-14 x 6.5-7.8 µm, av. 12.3 x 7.0, Qav. = 1.77, ellipsoid in profile view, long-ovoid in face view, all symetrical, thick-walled (about 1 µm)
Basidia 31-37 x 9-9.5 µm, 4-spored, clamped
Cheilos forming a sterile band, narrowly lageniform, clamped, 29-35 x 6-7, most astipitate.
Pleuros abundant, narrowly lageniform, cylindric-flexuose, clamped, 28-37(-50) x 5.5-8 µm.
Pileipellis an ixocutis

I went through both Guzman's keys and nothing seems to fit. P. quebecensis (= P. aztecorum, apparently) has smaller spores. P. cyanescens has larger and darker pileus, copious veil material and differently shaped pleuros.