The Bjerkandera adusta is a thin, soft, grey-brown polypore forming effused-reflexed patches to small brackets on dead hardwoods. The upper surface is grey to smoky-brown, often with subtle concentric zoning, and the margin is pale and sometimes slightly wavy. The pore surface is whitish to grey, bruising dark grey to blackish, a key field character.

Form: Thin effused-reflexed patches or small brackets, sometimes in overlapping tiers.
Cap: 10-60 mm wide, soft, flexible, grey to brownish, often faintly zonate.
Margin: Pale, thin, sometimes slightly lobed or wavy.
Pore surface: Whitish to grey, bruising dark grey to blackish; pores 4-6 per mm, round to slightly angular.
Context: Soft, fibrous, pale to greyish; thin.
Odour/taste: Not recorded

Growing as a crust fungus