Dryopteris marginalis, the marginal wood fern, is easily identified because the spores are carried along the very outermost edges of the fronds. A common evergreen easterner this native species thrives in rocky to woodland settings. In the garden it requires good drainage and will reward you with a leathery, forest green bouquet of rather ovate 18 to 30 inch fronds. For unexplained reasons, it is better adapted to locales east of the Rockies and there it comes highly recommended. Remarkably cold tolerant the marginal wood fern is suited for a broad range of Zones from a low of Zone 2 up to Zone 8.