fruiting 5-10 mm thick, reddish-brown ore, when ripe black, irregularly shaped pillow, in groups fused together to form crusts, rough knobby surface. spores. elliptic-bean-shaped, 8.5 to 10.5 x 3.5 to 5
mostly beech. the H.deustrum -> crusts thinner, more cohesive. a less common species: H. nummularia
this one was annoying to research on the internet: all site redirecting at first to hypoxylon - fragiforme or deustrum. And when i found H.multiforme --> the pictures weren't as good as in some of my books. And there was non english common name!!