As noted by The Columbus Dispatch, Ohio State's helmets include stickers that have a buckeye leaf on them. Buckeye leaves are grown on buckeyes trees, which is the official tree of the state of Ohio.
They are easily identifiable by their helmets -- not just Michigan's wings or Ohio State's scarlet stripe, but the stickers plastered all over them. The Wolverines and Buckeyes are two of 13 FBS ...