Armillaria ostoyae

Suprapellis filamentous, composed of very broad hyphae arranged in parallel with short cells between septa, from which bundles of heavily pigmented hyphae project, corresponding to the scales.

Subpellis formed of hyaline hyphae with morphology very similar to those of the suprapellis, in both cases apparently without clamp connections.

Lamellar edge with scattered elements functioning as cheilocystidia, cylindrical, sinuous to clavate.

Basidia clavate, slightly widened at the tip, clamped and 4-spored.

Spores ellipsoidal, thin-walled, guttulate, with one or several droplets inside, inamyloid in Melzer's reagent.