The Royal Fern is essentially a plant of the marshland. It never grows happily in dry or elevated situations. It is perhaps to be found at its best growing by the side of some river or stream. The Royal Fern has been found in many parts of the United Kingdom, though the plant suffers much from the depredations of trippers. Most fern-lovers know of places where this handsome species grows in abundance, but they wisely keep such knowledge to themselves. In the garden the Royal Fern grows well, but it must not suffer from lack of water, or it will prove but a poor subject. The fronds of the Royal Fern die down at the coming of the frost, and the young growth does not put in an appearance until the late spring.
The three species which must now be described would hardly be recognized as Ferns at all by most people. It has been indicated in an earlier chapter that there is really some doubt as to their true position, but for the sake of convenience they are here included amongst the Ferns. All the British species of the family Ophioglosseæ are somewhat inconspicuous plants, owing to their habit of growing mixed up with a lot of herbage.
_Ophioglossum vulgatum._ The generic name is formed of two Greek words--_ophios_, "a snake," and _glossa_, "a tongue"; a reference to the fact that the barren leaf was thought to bear a resemblance to a snake's tongue, though it must be confessed that the likeness is not very apparent. The word "vulgatum" is, of course, Latin for "Common." The Common Adder's Tongue.
In this species the frond is very definitely divided into two parts, a leafy portion and a spike. These are borne on a stalk about six inches in length which arises from a fleshy root-stock. The roots of the Common Adder's Tongue are quite coarse and entirely unlike the wiry roots of the majority of ferns. The leafy or barren portion of this curious frond is not divided in any way and is roughly egg-shaped. The fertile portion is in the form of a stalked spike, the spore cases being arranged on either side in double rows. The capsules are rounded in form and have no elastic ring, but open transversely when the contents are ripe. Attention should be called to the beautiful veining of the barren leaf of the Common Adder's Tongue, which forms a perfect network through the green tissue.