Filoboletus gracilis

Filamentous cutis, with hyaline interwoven hyphae, septate, with some clamped septa.

Caulocystidia present on the stipe surface, preferably on the upper part in clusters, ovoid to fusiform, some capitate.

Cystidia scattered, present on both the gill edge and face, fusiform to slightly ventricose.

Basidia clavate and 4-spored.

Spores subglobose to short ellipsoidal, smooth, hyaline, thin-walled, with an inconspicuous more or less central apiculus, and one or several lipid droplets.