Hypoxylon fragiforme

The fungus forms hard, brittle, hemispherical bodies (= stromata) 0.5-1.5 cm across.  Stromata are solitary or clustered and occur in groups of dozens or even hundreds.  They are dull brick-red to black, with a pimpled surface (seen easily with hand lens).  Pimples are the mouths of tiny ovoid perithecia embedded in the stroma . Common on the bark of dead beech.