A large annual bracket with a short thick lateral stem.  The flesh is white, covered with a pale grey-brown papery 'skin'.  The pores are rounded or angular, and small; 3 - 5 per mm.

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

Exclusively on fallen dead Birch wood and on standing dead or dying tree trunks.

All year round

The alternative name of Razorstrop Fungus originated because it has been traditionally dried and used for sharpening knives and razors.

Very common throughout Britain

Very common in Leicestershire and Rutland.