An annual crust, leathery in texture, resupinate or reflexed and associated with Oak.  The fertile surface is smooth and brown with a white margin, and stains red when bruised.  

Several other species stain red when bruised.  Stereum rugosum is similar, but usually greyish or pale brown; it can be found 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.  

On fallen wood and dead attached branches of Oak.

All year round

Widespread and fairly common in Britain

Frequent in Leicestershire and Rutland.