Fiddlehead sculpture at the Saint John Arts Centre by sculptor Jim Boyd in Saint John, New Brunswick, Canada.Fiddleheads or fiddlehead greens are the furled fronds of a young fern, harvested for use as a vegetable.Left on the plant, each fiddlehead would unroll into a new frond (circinate vernation).See bracken poisoning). The fiddlehead resembles the curled ornamentation (called a scroll) on the end of a stringed instrument, such as a violin. It is also called a crozier, after the curved staff used by bishops, which has its origins in the shepherd's crook.