Boletopsis grisea

Cuticle filamentous, composed of stout hyphae with abundant intracellular pigment and inconspicuous clamp connections.

Trama with more slender, likewise clamped hyphae.

Without cystidia.

Basidia clavate and 4-spored.

Spores small, more or less spherical, nodulose depending on the focal plane, containing a large lipid droplet inside, inamyloid in Melzer's reagent.