The Sea Spleenwort is hardly ever found at a great distance from the sea. It is most common on the coast of southern and western England, sometimes appearing in great abundance in rocky caves. The species also occurs in other parts of the United Kingdom where there is a rocky coastline. Happily it often grows in inaccessible places, and even where the plant can be reached with ease it is extremely difficult to tear the root-stock from its crevice. It seems to be almost impossible to grow the Sea Spleenwort in the open garden, although it is readily cultivated under glass. The species is evergreen in habit, though the foliage will not stand frost.
Asplenium ceterach. The specific name is considered to be a corruption of Chetherak, a name given to this Fern by early medical writers. In some books the species is called Ceterach officinarum. The Scaly Spleenwort.
This is the most distinctive of all the Spleenworts. The root-stock of the plant is tufted and scaly, and from this are sent down dense masses of roots which penetrate into the remote recesses of the wall or rock crevice where the Fern has made its home. The fronds vary greatly in length, and in a very exposed situation may not be more than an inch or so; in a sheltered and moist place they will be two or three times this size. The outline of the fronds is lanceolate. Strictly speaking, the fronds of the Scaly Spleenwort are pinnatifid, the leaf being designed with rounded lobes and deeply cut intervals. When held lengthways an idea is obtained of the wonderfully regular manner in which the cutting-out of the lobes has been devised. The segments of the fronds occur alternately on the rachis.
At first glance it is not an easy matter to discover the sori, for the back of the frond of this Fern is completely covered with brown scales; these are, however, white in the early days of the leaf.
By removing the scales it is possible to see the groupings of the sori; these are arranged in the form of rough lines. There is no very clear indication of an indusium, and indeed when one considers the protective scales this hardly seems to be necessary. It is generally considered that the scales on this Fern act in a protective manner during the long spells of dry weather. In such a condition the fronds of the Scaly Spleenwort appear to be trying to roll right up, whilst the lobes close in towards each other. To all appearance the plant is dead. It soon revives, however, after a good shower of rain.
The Scaly Spleenwort is to be looked for in limestone districts, where it occurs on old walls or amongst rocks, often in great abundance. It is said to be less common in Scotland than in other parts of the United Kingdom. Under cultivation the Scaly Spleenwort often comes to grief through excessive moisture; it is most happy in a crevice on a rockery. The Scaly Spleenwort is an evergreen plant.
Asplenium trichomanes. The specific name is probably formed of two Greek words—thrix, “a hair,” and manos, “soft.” This is doubtless a reference to the hair-like nature of the leaf-stalks. The Maidenhair Spleenwort.
This is a very familiar Spleenwort, not infrequently sold as the English Maidenhair. The plant has a stoutish root-stock, from which grow a quantity of fine roots; these often penetrate for a long way into the crevices of the rocks, or between the building materials of an old wall. The length of the fronds varies from a few inches to nearly a foot. The stipes is very short and is extremely brittle. On either side of the rachis, which is of a deep purple colour, the pinnæ are produced. These are borne on a very short stalk and are of an oval shape, being about half an inch in length. The margins of the pinnæ are occasionally slightly toothed. As a rule, the pinnæ are set in opposite pairs on either side of the rachis. A curious feature of the leaf-stalks of the Maidenhair Spleenwort is that they do not decay at once when the pinnæ fall off. Thus it is often possible to find thick bunches of them on the root-stock looking like so much dark hair.
Asplenium trichomanes. The Maidenhair Spleenwort.