Birch wood wart.
Other broadleaved tree species.
Found fruiting usually on stems and larger branches - often on fallen trees.
Annual . Hard. Individually small but often in clusters and sometimes covering large areas. Generally produces black and slightly flattened and warty fruiting bodies through lenticels or cracks in the bark.
Hypoxylon fragiforme (hemispherical).
Considered saprotrophic. Indicative of dysfunctional areas on standing trees.