How to Know the Ferns

by S. Leonard Bastin

Nephrodium cristatum. The specific name of this Fern simply means “crested,” and has reference to the fringed border of the frond. It may be pointed out, however, that there are not a few Ferns on which the name cristatum could with more reason have been bestowed. This species is also called Lastrea cristatum. There are a number of forms of this Fern.

This is a very handsome Fern, and it is a pity that it is not more common. The fronds are somewhat oblong in outline and have a very narrow appearance. The root-stock has a creeping habit and sends up tufts of fronds at intervals. These are very erect, and usually measure between one and three feet. The stipes is shorter than the leafy portion, and it bears a few brown scales. The pinnæ are arranged alternately on the rachis and these are not again divided, although they are very deeply cut. The colour of the fronds is of a bright green.

The sori are borne in lines on either side of the mid-vein of the lobe. These are covered at first by an indusium which is notched after the manner of that of the Buckler Ferns.

The Crested Buckler Fern is very rare, though it is found in a few localities—chiefly in the North of England. As a rule it occurs on boggy heaths, and if these conditions can be imitated in the garden, the Fern grows freely. The fronds are soon cut down by the autumn frosts, and the new growth does not appear until May.

Nephrodium spinulosum. The specific name means that the plant has little spines. This Fern is associated with other forms, and in some quarters has not been regarded as a definite species at all. Some of the varieties, or, as some authorities say, actually distinct species, with which it is associated have been called N. dilatatum and N. uliginosa. It may be mentioned that some botanists consider N. dilatatum to be the most important of the three forms. The chief points about N. dilatatum are the very dark green fronds which are extremely broad at the base; these spring from a massive caudex. The whole plant has a very robust appearance, and it is exceedingly common. Providing the situation is shady this Fern is not particular as to its place of growth. In the same way the preceding species N. cristatum is regarded by some as a doubtful species. On this account the beginner will find N. spinulosum rather difficult to identify, and he must be prepared for departures from the present type which is here described. The Prickly Buckler Fern.

Nephrodium dilatatum.

The frond of this species rises from an erect root-stock. The length of the leaves varies from one to three feet, and the stipes is usually about a third of this in measurement. The fronds are triangular in outline, and it is seen that the pinnules nearest to the rachis are considerably larger than the upper ones. This gives a very tapering appearance to the pinnæ. The borders of the pinnules are deeply cut, and the lobes are adorned with tiny points which give a somewhat prickly appearance. The lobes are most prominent on the lowest pinnules, and are also far more pronounced on the lowest pinnæ than they are on the upper divisions of the frond.

The sori are placed on small veins which grow outwards from the midrib of the pinnule. These are covered with kidney-shaped indusia. As has been indicated, the Prickly Buckler Fern varies enormously, both in size and in almost every other particular.

The Prickly Buckler Fern is not uncommon in parts of England, and is to be found in damp woods, especially by the sides of streams. It seems to be less abundant in other parts of the kingdom. It is of easy culture in the garden. The Prickly Buckler Fern retains its fronds through the winter.