A small shelf-like or hoof-shaped annual bracket, whitish in colour, with a soft, ridged, felty cap.  The pores are  small, at 4 - 6 per mm., more or less rounded.  When fresh it exudes whitish drops.   It has a very bitter taste. 

other Postia

taste

Photograph upper and lower fertile surface to show pores; note host plant and substrate

Conifer trees, almost always Spruce

Fairly frequent in Leicestershire and Rutland.