The arrangement of the sori is similar in both species.
The Soft Prickly Shield Fern has been found widely distributed in England and Ireland, though it is not so common in other parts of the United Kingdom. It is easily cultivated, and is evergreen in habit.
Woodsia hyperborea. The generic name of this species commemorates the botanist, Mr. Joseph Woods; the specific name is taken from two Greek words—hyper, “beyond,” and Boreas, “the north wind,” without doubt a reference to the fact that the species extends to the Arctic regions. The plant is also called Woodsia alpina. The Alpine Woodsia.
This is a very pretty little Fern. The tiny fronds, which are not more than two or three inches in length, spring from a tufted root-stock. The stipes is rather short and bears a few brown scales. The outline of the frond is oblong, and the leaf tapers slightly towards the base as well as at the apex. The fronds are once pinnate, and the pinnæ, which are lobed, are arranged in rather an irregular fashion on either side of the leaf-stalk. A curious feature of the Alpine Woodsia is that the fronds are jointed just above their connexion with the root-stock. When the leaves die the stalks break away at this point and leave the bases behind.
When the back of the frond is examined it is evident that we have here a very distinctive feature. The patches of spore cases are covered with a very thin indusium, and as time goes on this splits into divisions which resemble a number of hairs. The fronds are of rather a stout texture for so small a Fern, and in all parts show an inclination to be hairy.
The Alpine Woodsia is a very rare Fern, and there are only a few recorded localities of it in England and Wales. It makes its home on moist rocks on the slopes of high mountains. This little Fern is fairly easily cultivated. The fronds disappear in the winter.
Woodsia ilvensis. The Oblong Woodsia.
Woodsia ilvensis. The specific name refers to the island of Elba (Ilva), where this plant was first of all discovered. In some quarters this plant is held to be merely a variety of W. hyperborea. The Oblong Woodsia.
The fronds of this Fern rise from a tufted root-stock. The stipes is short, but the frond as a whole is larger than that of the Alpine Woodsia, and may be as much as six inches in length. The outline of the fronds is oblong, tapering towards the base and at the apex. Over the whole frond, both on the upper and the lower side, is a covering of fine hairs. Usually the hairiness of the Oblong Woodsia is very pronounced. The covering is so thick on the underside that it is rather difficult to discover the sori. These have the same curious divided indusia to be observed in the Alpine Woodsia.