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.
Pteris aquilina. 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.