A perennial crust, very tough and leathery in texture, with zonate flesh (representing a series of annual growths).  It is usually resupinate but may reflex to show a narrow dark brown cap.  It is associated with deciduous trees.  The fertile surface is smooth and pale pinkish-brown, and stains red when bruised. 

Several other species stain red when bruised.  Stereum gausapatum is similar, but usually a brighter brown; it is almost always on oak. Stereum sanguinolentum is similar, but associated with conifers. 

red stain/host

Photograph fertile surface and any staining when bruised, note host plant and substrate.  

Deciduous trees, typically hazel, also beech, oak, and birch

Widespread and frequent in Britain.