The octofoil is an old heraldic mark for a ninth son, the white center surrounded by his eight brothers, which is exactly why the 9th Division wears eight leaves. The War Department approved it for...
The octofoil on the 9th Infantry Division patch is the heraldic mark of a ninth son, which is how the Old Reliables came to wear an eight-petaled flower for the number nine. In Vietnam that flower...