Xanthomendoza hasseana (Poplar Sunburst Lichen)
Both photos (above & below) were taken at Chiwaukee Prairie State Natural Area

Photo was taken at Hixon Forest, Lacrosse County 
Photo was taken at Lacrosse Blufflands
Photo was taken at Quincy Bluff State Natural Area
Photo was taken at Giant White Pine State Natural Area
Photo was taken at Ice Age Trail, Indian Lake Segment
Photo above was taken at Timberland Hills Trails, Barron County