CHAPTER V

THE BRACKEN FERN AND TWO INTERESTING SPECIES

Many members of the Fern tribe are of a retiring disposition, and to find them we must search in out-of-the-way corners. This cannot be said, however, of the leading subject under discussion in this chapter, for of all native ferns there is certainly none with a wider distribution than the Bracken. As one of the few ferns not needing a moist situation, the Bracken is able to make itself at home almost anywhere, save perhaps in the vicinity of large manufacturing towns. The sub-family Pterideæ to which the Bracken belongs has not a large number of representatives in the United Kingdom. In the Ribbon Ferns and the Maidenhairs of our greenhouses we have evidence that, as far as the world at large is concerned, the Pterideæ are very numerous.

_Pteris aquilina._ The generic name is derived from the Greek word _pteron_, “a wing,” and the specific name comes from the Latin _aquila_, “an eagle.” The Bracken Fern.

The height and general outline of the Bracken Fern varies enormously. On exposed hillsides the plant may be barely a foot in height, with leaves correspondingly small. In the sheltered wood it is not an uncommon thing to discover specimens which may be taller than a man. In such cases the fronds may measure as much as four feet at their widest parts. The fronds of the Bracken start to develop—in the South of England at any rate—about April and are fully expanded by Midsummer. During September they turn a beautiful golden brown and finally die altogether, although the leaves do not decay quickly. The Bracken is, of course, a very strong-growing perennial, and the plant has a wonderful system of underground rhizomes. In a strong-growing specimen these rhizomes may be as thick as a finger and are very succulent. They are of a jet-black colour, and at the base of each frond there are sent out a quantity of fibrous roots. The fronds arise from either side of the rhizome, and often not more than one or two are developed in a single season. By examining the rhizome it is possible to discover the buds containing the new fronds for two years ahead.

The fronds of the Bracken Fern are roughly triangular in outline. That portion of the stipes which is under ground is of a dark brown colour, but the portion above the surface is of a bright green tint. The rachis, or foliage-bearing portion of the stalk, represents about half of the whole. On either side of the rachis the pinnæ are arranged in pairs, which are placed nearly but not quite opposite to one another. These pinnæ are divided again, and in very large examples there may be a further subdivision. In all the parts of the frond of the Bracken there is a tendency for less division at the apices of the different portions. It should be noted that the lowest pairs of pinnules, those next to the rachis, are often much modified; they are always small, and in some cases the upper pinnules are missing.

It is along the margins of the lobes of the leaf that the sporangia are produced. There is no proper indusium, the spore cases being protected by the rolling back of the margin of the leaf. When the sporangia are mature the back of the Bracken frond, with its outline of bright brown, is very pretty. The number of spores produced is prodigious, and it is a common experience to find one’s boots covered with the brown dust after walking through the fronds. It is believed that the Bracken is rarely propagated in a natural state by the agency of its spores. The strong-growing rhizomes provide a very effective method of increase, and as has been stated, the Bracken Fern is very quick to claim any land which has been allowed to go out of cultivation.

The Bracken Fern grows almost everywhere in the United Kingdom. It is, however, not able to hold its own on mountains of greater elevation than two thousand feet. There seems to be a popular impression that the Bracken is a difficult plant to grow in the garden. This is not really the case, the trouble, as a rule, arising from the careless manner in which the rhizomes are torn up when the plant is removed. The Bracken is, of course, a useful subject for placing in shrubberies and under trees, but seeing that the travelling rhizomes take up a great deal of room, it should be kept out of the ordinary borders.

_Adiantum capillus-veneris._ The generic name is connected with a Greek word _adiantos_, which means “dry or unmoistened,” this having reference to the fact that water rolls off the frond of this Fern. _Capillus-veneris_ simply means “the hair of Venus,” and this doubtless refers to the shining black leaf-stalk and its delicate branches. The True Maidenhair.

This is one of the most beautiful of our native ferns, and it would probably have been exterminated long ago in this country were it not that it so often grows in inaccessible positions. The True Maidenhair loves a position which is shady and where moisture is abundant. From a slender, creeping rhizome, which is black in colour, the fronds arise. These vary greatly in length, and may measure anything from six inches up to a foot, or even more, according to the conditions in which the plant is living. The stipes, which is usually about the same length as the leafy portion, is jet-black, and like the rachis and all its branchings, is of a very wiry nature. In a moderate-sized specimen the arrangement of the frond would be on the following lines. On either side of the rachis the pinnæ are produced; these usually branch alternately from the central stalk. The pinnæ bear fan-shaped pinnules, which are attached to the stalk of the leaf-division by very fine stalks. The margin of the pinnules is much notched and veined. Where the frond is of a very large size they may be divided three times.

In the case of a fertile frond the edges of the pinnules are turned back in a very striking way. If we turn up the fold, it is possible to see the sporangia arranged on the underside. Before the fertile leaf has reached maturity the upper part of the fold has a whitish appearance; finally it turns black.

The True Maidenhair Fern is more widely distributed than is generally supposed in the South of England and in Ireland. It is a delicate species, and, generally speaking, is restricted to those parts of the kingdom where the winter is mild. It may be seen growing abundantly on old quarries in Cornwall, as a rule quite out of reach. The Maidenhair Fern is a fairly easy plant to grow in pots, though it likes a moist atmosphere. Curiously enough, it is not so simple a plant to cultivate as some of the exotic species. The True Maidenhair is an evergreen plant.

_Cryptogramme crispus._ The generic name of this fern is derived from two Greek words, _kruptos_, “hidden,” and _gramme_, “a line,” having reference to the fact that when mature the sori are arranged in lines round the margins of the fronds. The specific name, _crispus_, is an apt one, when the crisped or curled appearance of the barren fronds is considered. In some books this species is called _Allosorus crispus_. The Parsley Fern.

A very attractive species bearing both barren and fertile fronds. The former in their general appearance certainly bear a resemblance to Parsley. The Parsley Fern has a thick root-stock from which the fronds grow up in tufts. The barren fronds, which will be considered first, grow to the height of about six to nine inches. The stipes is somewhat longer than the rachis, and it is of a whity-green colour. The outline of the barren frond is roughly triangular, the apex of the leaf being rather blunt. The pinnæ are placed alternately on either side of the main stem, and these bear pinnules which have their margins deeply cut. In very large specimens the fronds may be divided three times. The barren fronds grow on the outside of the tuft. The fertile frond is somewhat taller than the barren leaf, to which it bears a resemblance in its general form. The pinnæ, of course, are very much restricted. At first the sori are rounded, but as they mature they spread so as to form almost unbroken lines round the margins of the pinnules. The sori have indusia, but this is hidden by the margin of the pinnules, which are recurved.

There are few more local species than the Parsley Fern. The plant loves to grow amongst rocks which are often scattered about on the slopes of mountains. Its two chief strongholds seem to be the Snowdon district in Wales and the mountainous parts of Cumberland. In some localities of these districts the plant grows in the greatest abundance, happily often out of the reach of the tourist. The Parsley Fern has also been recorded in the West of England, and it occurs in Scotland. It is easily cultivated, if the fact is borne in mind that it is a rock species needing good drainage. It loses its bright, pretty colouring in a sunny position. The Parsley Fern sends up its green fronds in the month of May, and the fertile leaves follow soon after. The foliage disappears in the winter.