Tricholoma ustale

Species typical of broadleaf woods, such as beeches or oaks, with a convex to flattened cap, 3 to 9 cm in diameter, with a smooth and sticky surface bearing radial fibrils, reddish-brown, adnate cream gills that become spotted with age, a cylindrical stipe with abundant longitudinal fibrils, without an annular zone, a slight mealy odour, and a slightly bitter mealy taste.

Filamentous cuticle formed by hyphae arranged parallel to slightly intertwined with each other, 3 to 6 µm wide, those of the upper part slightly separated from each other by gelification, with an encrusting brown pigment inside, all septate with simple septa (without clamp connections).

Without cystidia.

Lamellar trama regular or parallel.

Basidia cylindric-clavate, 25 to 30 µm long by 5 to 7 µm wide, with a simple base and tetrasporic.

Spores ellipsoidal, smooth, hyaline, thin-walled, with an eccentric apiculus at one end, 5.5 to 7 µm long by 4 to 5.5 µm wide, with one or more oil drops inside, and inamyloid in Melzer's reagent.