Dryopteris filixmas (syn. Lastrea filixmas) (male fern), the best known of all hardy ferns, deriving its common name from its robust, sturdy growth. A well-grown specimen is particularly handsome with graceful, delicate pale green fronds attaining a height of 2-1/2 to 3 ft. In early spring, when they start to develop, the fronds are curled round like the flutings of a snail shell and are protected from the rain and wind by large, chaffy, light brown hairs.
D.f. Foliosa, 2 to 3 ft., stems thickly covered with dark brown scales and over-lapping foliage arranged like roof-tiles.
D.f. Furcans, 2 to 3 ft., leaflets divided, mostly once, but occasionally twice or even three times, so that it somewhat resembles a fish tail.
D.f. Polydactyla, 2 to 3 ft., each branchlet is divided towards the apex and again sub-divided, eventually forming a crisp tassel.
D.f. Robustissima, 4 ft. or more, the best fern for sunless town gardens. Plant where it has ample room to develop and can remain undisturbed for many years.