The sori are very freely scattered on the lobes or pinnules at the back of the frond, and these are covered with the curious hooded indusia which were noticed in the last species.
The Mountain Bladder Fern is perhaps the rarest of all our native species. It is at home in mountainous districts, and seems only to have been noticed in a few localities in Wales and Scotland. Probably it would be seen more often were it not that it grows in positions which are not of easy access. It should be given the same treatment in the garden as that recommended for the Brittle Bladder Fern. The fronds disappear in the winter.
In some books a species is given, known as Cystopteris alpina or regia. The plant nearly resembles Cystopteris fragilis, although it is somewhat smaller. This is a very doubtful native, as it seems only to have been recorded in one or two localities where it may have been naturalized.
CHAPTER VII
THE LADY FERN AND THE SPLEENWORTS
The sub-family Asplenieæ has a large number of representatives in the United Kingdom. There is much division of opinion as to the real place of the Lady Fern. Many botanists consider that the species is a true Asplenium. Others regard it as the solitary British representative of the genus Athyrium. All Fern growers support the latter view. Some of the small Spleenworts are quite common.
Athyrium or Asplenium Filix-fæmina. The generic name of the Spleenworts is derived from the Greek word splene, “the spleen,” this having reference to the fact that in the old days a medicine derived from the leaves was held to be a remedy for diseases of the spleen. The specific name is simply a combination of two Latin words—Filix, “a fern,” and fæmina, “a woman,”—that is, “Lady Fern,” a name no doubt given on account of the elegant appearance of this species, particularly when it is compared with the Male Fern (N. Filix-mas). The Lady Fern.
Athyrium filix-fæmina. The Lady Fern.
Although it is altogether more fragile in appearance, the growth of the Lady Fern bears a resemblance to that of the Male Fern. We notice the same tall fronds rising from a stout root-stock covered with brown scales. In a favourable situation, such as a damp hedge, these fronds may grow to the length of four feet, or even more. They are of a beautiful pale green colour, and being of a thin texture soon disappear at the approach of winter. The stipes is usually about one-third of the whole leaf, and is sometimes of a brownish colour. The stalk is remarkable for its brittle nature. The outline of the fronds is lanceolate, and they taper very decidedly towards the base as well as at the tip. The leaves of the Lady Fern are bi-pinnate. The pinnæ are placed either in pairs, or alternately, on opposite sides of the rachis, and these in turn are divided into toothed pinnules. In the case of both the pinnæ and the pinnules the distinctiveness is lost towards the upper portion.
The sori are very abundant, but as these are small they should be carefully examined. They occur about midway between the central vein of the pinnule and the margin of the leaf. The indusium is not clearly linear, being more in the shape of a horseshoe, but this character can only be recognized before the delicate covering has started to shrivel. There are a huge number of variations of the Lady Fern, but many bear a more or less striking resemblance to the type.