This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
In the Male-fern - so-called by our fathers owing to its robust habit as compared with the tender grace of one they called Lady-fern (Asplenium filix-faemina) - we have an advance in the intricacy of frond-division. Our page is not sufficiently large to represent the whole of the frond, but the portion we give shows that the pinnae are themselves again divided into pinnules. This fern grows to a great size, its rootstock very thick and woody, its fronds erect and three or four feet high. As a rule the rachis and its continuation below the leafy portion (stipes) are shaggy with loose golden-brown scales. The spore-capsules are in little round heaps in rows along the pinnae, and each heap is covered by a thin kidney-shaped involucre. Note in the unrolling of a young frond how beautifully the whole is packed up. The lateral divisions of the pinnae are rolled each on itself, then the pinnae are rolled up from their tips toward the rachis, and finally the whole frond is coiled up from the tip downwards. This is the characteristic vernation of ferns, and differs greatly from the packing of undeveloped leaves in the leaf-buds of flowering-plants.
The genus Nephrodium (named from nephros, the kidneys, in allusion to the involucre) contains half-a-dozen other British species, of which the most frequent is the Broad Buckler Fern (N. spinulosum), with arching fronds, broad at the base, the stipes sparingly clothed with dark-brown scales. Pinnules toothed, the teeth ending in long soft points. Damp woods.
Mountain fern (N. oreopteris), with habit of Male fern, but stiffer, and of a yellow-green hue. Spore-heaps near the margins of the pinnae. High hills and mountain pastures.