Dryopteris carthusiana

Dryopteris carthusiana is a perennial species of fern native to damp forests throughout the Holarctic Kingdom. It is known as the narrow buckler-fern in the United Kingdom, and as the spinulose woodfern in North America. It is a tetraploid of hybrid origin, one parent being Dryopteris intermedia, known in North America as the intermediate wood fern, and an unknown, apparently extinct species dubbed Dryopteris semicristata, which is also the presumed parent of the hybrid-origin Dryopteris cristata....read more on Wikipedia.