The rounded stroma or communal fruitbodies on the bark of Beech trees are initially pinkish-brown or orange-brown; later becoming darker brown then black.  The surface is bumpy with the developing perithecia inside the stroma, and there are small small ostioles on the surface through which the spores are eventually ejected. 

The Beech Barkspot Diatrype disciformis has small erumpent black warts on beech; these have tiny pores but do not have a bumpy surface.  Similar woodwarts or barkspots are found on other deciduous trees. 

host

Photograph in its habitat; not substrate and associated tree species

On the dead wood of Beech.

All year round.