Hypoxylon atropunctatum (Hypoxylon Canker of Oak),

synonyms Diatrype atropunctata, Biscogniauxia atropunctata

Both photos (above & below) were taken in Spring Green

See MycoBank for information

Both photos (above & below) were taken at Mirror Lake State Park

Both photos (above & below) were taken at Mirror Lake State Park

Both photos (above & below) were taken at Governor Dodge State Park

Both photos (above & below) were taken at UW-Madison Arboretum