Clinton's woodfern

Dryopteris clintoniana, commonly known as Clinton's wood fern, is a fern of hybrid origin native to the northern hemisphere. It is a fertile hexaploid, arising as a species by doubling of its chromosome number from a hybrid between Dryopteris cristata, a tetraploid, and Dryopteris goldieana, a diploid. It is more northern in its range than either parent species.