How to Know the Ferns

by S. Leonard Bastin

The Black Maidenhair Spleenwort is an exceedingly common Fern. It occurs in almost all parts of the United Kingdom, although, of course, near towns it is usually rooted up. The species is of very simple culture and will be quite happy on an ordinary rockery. The Black Maidenhair Spleenwort retains its fronds throughout the winter.

Asplenium lanceolatum. The specific name has reference to the fact that the outline of the frond is lanceolate. The Lanceolate Spleenwort.

This is a species which in its early days is sometimes confused with the Black Maidenhair Spleenwort. The fronds, which are lanceolate in outline and about four inches to a foot in length, arise from a tufted root-stock; the stipes is usually about a third of the frond. The colour of the stipes, and also part of the rachis, is bright brown, and this contrasts finely with the handsome green of the leafy portion. The actual length of the fronds will vary to a considerable extent, this depending upon the amount of moisture available. The design of the frond, when it is developed, shows by its lanceolate outline a marked feature which distinguishes it from the triangular outline to be seen in the case of the Black Maidenhair Fern. The frond is twice pinnate, and as a rule the pinnæ are opposite; these are roughly egg-shaped in form. The pinnules have serrated margins.

The sori are placed on veins which branch out from the mid-veins of the pinnules. At first the collections of sporangia are long and narrow, and covered with a white indusium. As the capsules mature the sori spread out over the under-surface of the frond.

The Lanceolate Spleenwort is usually met with near to the sea or in mountainous districts. It is rather local, although it sometimes occurs in great plenty on damp rocks. It is said not to occur in Scotland. In a suitable rocky corner there is no reason why the Lanceolate Spleenwort should not be grown in a garden. The situation should be well drained, but a sufficiency of water is needed. The Lanceolate Spleenwort remains green throughout the winter.

Asplenium marinum. The specific name marinum has, of course, reference to the fact that the Fern is to be found near the sea. The Sea Spleenwort.

This is an interesting and a most beautiful species, often growing abundantly from the roof-crevices of caves on the coast. The root-stock of this plant is stout, and from it are produced a large number of fine black roots which penetrate into the rocky fissures. The fronds are, as a rule, four or five inches in length, though in favourable situations they may be very much longer. The stipes is somewhat short, hardly ever more than a third of the length of the frond, and sometimes less than this. In most cases the stipes is of a purple colour, and the leafy portion of the frond is of an exceptionally fine green shade. The leaves are freely produced in tufts and are roughly lanceolate in outline. The fronds of the Sea Spleenwort are only once pinnate, the pinnæ—which are usually about an inch in length—being, as a rule, oblong in outline. They are, however, decidedly variable in form, some being egg-shaped. A curious feature of the pinnæ is that they are unequal in shape at the base, the lower part appearing to have been cut off whilst the upper portion is greatly enlarged. Between the lower pinnæ the rachis is winged, but this feature disappears at the tip of the frond where the pinnæ run together.

Asplenium marinum. The Sea Spleenwort.

The sori are to be found on the underside of the pinnæ, arranged in lines on either side of the mid-veins. During the early days the cluster of sporangia is covered with very distinct indusia, but as the capsules ripen, these disappear.