The sori are placed in the form of lines on veins which branch from the mid-vein of the pinnæ. In the early days the clusters of spore capsules are covered with indusia; as the capsules mature these are thrown off, and finally the sori may spread over the back of the pinnæ.
The Maidenhair Spleenwort is an exceedingly common Fern in many parts of the United Kingdom. It is often found on old walls in great abundance. Happily it is not an easy plant to exterminate; for, owing to the long roots already mentioned, it is a difficult matter to dislodge a plant from its crevice. In the garden the Maidenhair Spleenwort is perfectly happy on a rock ledge; it should not be given a large amount of moisture. The Maidenhair Spleenwort is an evergreen species.
Asplenium viride. Here the specific name is formed of the Latin word viride, “green,” obviously a reference to the bright colour of the fronds. The Green Spleenwort.
In some respects this species resembles the Maidenhair Spleenwort, though there are certain important distinctions. In the first place, there is the bright green colour of the whole plant; this is very different from the dull shade of the Maidenhair Spleenwort. The Green Spleenwort also grows in damp situations, and would not be at all happy on the top of a wall. Most distinctive of all, the Green Spleenwort has a bright green rachis to its fronds, although the stipes has a tendency to be purple in colour. In other respects the two plants are very similar. We notice the same narrow frond with the rounded pinnæ set on either side of the rachis, sometimes in pairs and sometimes in alternation. The margins of the pinnæ are inclined to be notched.
The sori are narrow, and when young are covered with an indusium. It is said that even when ripe the sporangia hardly ever spread over the entire surface of the pinnæ, as is to be seen in the case of the Maidenhair Spleenwort.
Asplenium viride. The Green Spleenwort.
The Green Spleenwort is a much rarer species than the Maidenhair Spleenwort. It grows in wild and often mountainous situations in various parts of the United Kingdom. As has already been indicated, it likes rather damp situations, and is to be seen at its best in moist places. The Green Spleenwort is rather a difficult plant to grow in the garden, and it is happiest of all in a humid greenhouse—unless, of course, a very favourable situation can be found out of doors. The fronds of the Green Spleenwort generally last through the winter.
Scolopendrium vulgare. In this case the generic name is derived from scolopendra, the Latin name for a “centipede”; this has reference to the supposed resemblance of the lines of spore cases to the legs of a centipede. The specific name is, of course, simply Latin for “common.” The Hartstongue.
