Fig. 51.—Forms of Basidiomycetes. A, Tremella, one-half natural size. B, Agaricus, natural size. C, E, Polyporus: C, × ½; E, × ¼. D, part of the under surface of D, natural size. F, Clavaria, a small piece, natural size. G, Hydnum, a piece of the natural size.
Of the last, or naked-fruited forms, the commonest belong to the genus Clavaria ([Fig. 51], F), smooth-branching forms, usually of a brownish color, bearing the spores directly upon the surface of the branches.
CHAPTER XI.
SUB-KINGDOM IV.
Bryophyta.
The Bryophytes, or mosses, are for the most part land plants, though a few are aquatic, and with very few exceptions are richly supplied with chlorophyll. They are for the most part small plants, few of them being over a few centimetres in height; but, nevertheless, compared with the plants that we have heretofore studied, quite complex in their structure. The lowest members of the group are flattened, creeping plants, or a few of them floating aquatics, without distinct stem and leaves; but the higher ones have a pretty well-developed central axis or stem, with simple leaves attached.
There are two classes—I. Liverworts (Hepaticæ), and II. Mosses (Musci).
Class I.—The Liverworts.
One of the commonest of this class, and to be had at any time, is named Madotheca. It is one of the highest of the class, having distinct stem and leaves. It grows most commonly on the shady side of tree trunks, being most luxuriant near the ground, where the supply of moisture is most constant. It also occurs on stones and rocks in moist places. It closely resembles a true moss in general appearance, and from the scale-like arrangement of its leaves is sometimes called “scale moss.”
The leaves ([Fig. 52], A, B) are rounded in outline unequally, two-lobed, and arranged in two rows on the upper side of the stem, so closely overlapping as to conceal it entirely. On the under side are similar but smaller leaves, less regularly disposed. The stems branch at intervals, the branches spreading out laterally so that the whole plant is decidedly flattened. On the under side are fine, whitish hairs, that fasten it to the substratum. If we examine a number of specimens, especially early in the spring, a difference will be observed in the plants. Some of them will be found to bear peculiar structures ([Fig. 52], C, D), in which the spores are produced. These are called “sporogonia.” They are at first globular, but when ripe open by means of four valves, and discharge a greenish brown mass of spores. An examination of the younger parts of the same plants will probably show small buds ([Fig. 54], H), which contain the female reproductive organs, from which the sporogonia arise.