Cap: 1–4 cm wide 1.5-8.5 cm wide, brown when fresh (spring), fading to white when old (by autumn), round to hoof-shaped, with a leathery membrane covering the pore layer except for a ~ 5 mm diameter hole bored by beetles next to the bark at the bottom. Attached to the bark by a hyphal cord emerging from the beetle tunnel.
Pore surface: pale brown fading to white, covered with a thick white to yellow membraneous veil that opens at maturity
Pore shape: circular, 3-5 per mm
Spores: pinkish, 8-12 × 3-5μm, 9-16 × 3-5 μm, cylindric, smooth, hyaline, inamyloid.
Hyphal system trimitic. Generative hyphae 3–7 μm diameter with clamp connections, inflated at branches to 15 μm; skeletal hyphae 2.5–8.0 μm diameter, binding hyphae 1.5–2.5 μm diameter; cystidia lacking; cystidioles fusoid, 20–28 × 5–7 μm; basidia clavate, 24–27 × 9–11 μm, four sterigmate; basidiospores 8–12 × 3–5 μm, cylindrical, walls hyaline, thin, smooth, neither amyloid nor dextrinoid.