Stereum hirsutum

On bark or decaying wood of broadleaves on the ground, such as Fagus, Quercus, or Alnus, with effused-reflexed basidiomes; pileus projecting 0.5 to 3 cm, 1 to 2 mm thick, zoned and velvety (hirsute) surface not reddening upon cutting or bruising; smooth orange-yellow hymenium; elastic to coriaceous in consistency.

Hyphal system dimitic, with thick-walled skeletal hyphae, without septa, 3 to 5 µm wide; and generative hyphae, thin- to moderately thick-walled, 2 to 3 µm wide, septate with simple septa.

Cystidia absent, but with some thick-walled terminal skeletal hyphae projecting past the basidial level, with rounded apices.

Basidia cylindrical-clavate, 30 to 45 µm long, 3.5 to 4.5 µm wide, simple-based and four-spored.

Spores cylindrical-ellipsoidal, smooth, hyaline, thin-walled, 5 to 6.5 µm long, 2 to 3 µm wide, with an eccentric apiculus at one end, containing granular matter inside, and distinctly amyloid in Melzer's reagent.