How to Know the Ferns

by S. Leonard Bastin

CHAPTER VI
THE MALE FERN AND ITS RELATIVES

Apart from the Bracken Fern which, as we have seen, is abundant almost everywhere, there are few ferns more common than certain of the leading members of the sub-order Aspidieæ. The British representatives of this sub-order include the important genus Nephrodium, of which the Male Fern is the leading example. In addition we have the Shield Ferns (Aspidium), and also some interesting species gathered together under the genera Woodsia and Cystopteris.

Nephrodium Filix-mas. The generic name is derived from the Greek nephros, “a kidney,” this having reference to the kidney-shaped indusia which is typical of the genus; Filix-mas, of course, is a name formed of two Latin words, filix, “a fern,” and mas, “a male.” In some books the species is called Lastrea Filix-mas, and Aspidium Filix-mas. The Male Fern.

Nephrodium filix-mas. The Male Fern.

One is almost tempted to follow the example of the early writers of botanical works and to say that the plant is so well known that “it needeth no description.” However, such a fine Fern, common though it be, is certainly as worthy of a notice as any species within the covers of this book. A very characteristic feature of the Male Fern is its stout and sometimes very upright stem or caudex. In some plants this is at times so large that it almost resembles a short trunk. It will readily be seen that the leaves arise from the outside of the crown of the plant, whilst at the base of the stalks occur the fibrous roots. Within the circle of the developed leaves we may find the immature fronds; the least advanced of these may not develop for three years. The crown of the plant, as well as the stipes and the rachis, are more or less covered with brown scales. The length of the fronds of the Male Fern vary enormously. In a favourable situation the leaves may measure as much as three feet or more, though an average example would be a good deal less than this. A well-developed plant should show six or more finely developed fronds arranged cup-fashion round the central stem. The shape of the leaf of the Male Fern is roughly lanceolate, broadest in the middle and tapering at each end. The frond is bi-pinnate, and the pinnæ are long and taper to a fine point. The pinnules are rather blunt, and frequently show serrated edges. The upper portion of the frond is pinnatifid, and in many of the higher pinnæ it is only the pinnules nearest to the rachis that are distinct.

Practically all the fronds are fertile, though the sori occur chiefly on the upper portions of the leaves. The brown patches are to be found arranged in a single line on either side of the central vein of the pinnules. The sorus is circular and is covered with an indusium which is notched or kidney-shaped. In the early days the indusium is of a lead colour, but as the sporangia ripen underneath the brown colouring shows through the thin covering. The foliage of the Male Fern is of a bright green tint, changing to a duller shade as the leaves become older. Not uncommonly the fronds last in good condition through a large part of the winter when the season is mild.

It is now recognized that the Male Fern may be divided into three sub-species. These are called N. filix-mas (true), N. pseudo-mas, and N. propinqua. The differences are not very obvious to the beginner, but it is said that the first named is only partially deciduous—the fronds lying prostrate during the winter. In the case of N. pseudo-mas, the fronds are of a leathery nature, and the plant is practically evergreen in sheltered positions. A well-established feature of N. propinqua is that the foliage completely dies away in the autumn.

The Male Fern is abundant in all parts of the United Kingdom where the conditions are in any way suitable. Naturally it is of easy culture in the garden. The new fronds, which are very pretty when they are uncurling, put in an appearance in the month of April.

Nephrodium Thelypteris. The specific name of this plant is a compound word derived from the Greek, meaning “ladyfern”; the title probably has reference to the delicate growth of the species. The Fern is also called Lastrea Thelypteris. The Marsh Buckler Fern.