Circinate vernation is the name for the way in which new
fern fronds emerge. When a new fern frond is emerging, the frond is called a crozier (after the shepherd's crook) or fiddlehead (after the scrollwork at the top of a violin). This is because the frond is tightly curled up. This means that the tender growing tip of the frond is protected in the middle of the coil, while the lower parts of the frond are toughening up and beginning to
photosynthesize, supporting the further growth of the frond.