In English folklore, mushroom rings were known as fairy or pixie rings. These were caused by the wee folks dancing in a circle. As they wore down the grass, they left a circular pattern of basidia (a type of mushroom) behind.
Pixie cut with glasses!! It does work!
Gorgeous little fairy folk from Fairystudiokallies.
Shag Haircuts, Fine Hair and Your Most Gorgeous Looks
A few more layers in the back and this might work.