Posted on 14 April 2011 by David Razor strop fungus in Sutton Park Birch polypores could be used to sharpen old-fashioned cut-throat razors. The birch tree these were growing on was by the road in Sutton Park. The trunk was in effect a ten foot tall stump, lacking any branches. Post navigationPrevious post: Apple budsNext post: Sandstone cliff by river Stour aqueduct