CRYPTOGAMOUS PLANTS.

These plants are generally described as being without spiral vessels, and consisting only of cellular tissue; but spiral vessels are known to exist in the Ferns, and are said to have been found in the Mosses. Whether this be the case or not, it is evident that the plants included in this division are very different from all that have preceded them, and occupy a lower grade in the scale of vegetable creation. They are divided into two sub-classes: viz. the FoliaceÆ, or those with leaves, and the AphyllÆ, or those without leaves; both of which are without visible flowers, though some have what are called anthers, and the Mosses have something resembling a style and stigma. They may also be said to have no seeds, for the spores, or sporules as they are called, are very different from the seeds of vascular plants, and they have neither cotyledon nor embryo.

SUB-CLASS I. FOLIACEÆ.

ORDER CCXI.—FILICES.—THE FERN TRIBE.

Though some of the Ferns are so common that almost every one must have seen them, very few persons are aware how very curiously they are constructed. In the first place, they may be said to have neither stems nor leaves, and neither flowers nor seeds. The different parts of the plant spring from a rhizoma, and the leaves, which are called fronds, have their veins neither branched nor in parallel lines, but forked. On the back of the leaves are some curious brown spots of various shapes called sori; and these, which generally form under the outer skin or cuticle of the leaf, and which always spring from one of the veins, contain a number of small grains, called the thecÆ, which are in reality cases containing the sporules or seeds. When the sorus forms under the cuticle of the leaf, the membranous part raised, which resembles a blister, is called the indusium; but sometimes the sori are naked, that is, they are formed on the outside of the cuticle; and sometimes they are found on the margin of the leaf, which folds over them, and supplies the place of the indusium. The order is generally divided into two sections, called PolypodiaceÆ and OsmundaceÆ. The first contains those plants which unroll their leaves, when they rise from the stem, and which have their sori either on the back or on the margin of the frond. The thecÆ are on stalks, and they are furnished with a ribbed, elastic, articulated but incomplete ring, which seems to serve as a sort of hinge when they burst. This elastic ring is a continuation of the stalk of the theca, which always bursts on the opposite side. The following are the principal genera in this division: Polypody (Polypodium), sori without any indusium; Shield Fern (Aspidium), Bladder Fern (Cistopteris), and Spleenwort (Asplenium), all of which have their fronds pinnate or pinnatifid; Maiden Hair (Adiantum), Hart’s-tongue (Scolopendrium), the frond of which is simple and shaped like a tongue, and the sori oblong; and Brake (Pteris), the leaves of which are pinnatifid, with the sori placed round the margin so as to form a continuous line, and the edge of the leaf turned over them. The rhizoma of the Brake is eaten in many countries, and the fronds, when burnt, yield alkali, which is used in making both soap and glass.

The second division OsmundaceÆ comprises those Ferns which apparently have flowers; the flowers, however, being merely sori, with the leaves on which they grew shrivelled up round them. The most remarkable of these is the flowering Fern (Osmunda regalis); but others are—the Grape Fern or Moonwort (Botrychium), a species of which, a native of North America, is called there the Rattle-snake Fern; and the Adder’s Tongue (Ophiglossum). The Tree Ferns of New Zealand are magnificent plants. The trunk or stipe rises to the height of forty or fifty feet without a branch, and then terminates in a head of noble fronds, which hang down on every side like a plume of feathers. The wood of these trees when cut across, instead of being in circles like the wood of Dicotyledonous trees, or full of pores like that of the Endogens, is marked with a number of zigzag lines, the traces of the stalks of old fronds which have grown together and formed the stipe.

ORDER CCXII.—LYCOPODINEÆ.—THE CLUB-MOSS TRIBE.

These plants appear to occupy the intermediate space between the Ferns and the Mosses. They have creeping stems, and grow two or three feet high; the erect stems being clothed with imbricated leaves, in the axils of which these are produced. Some of them open into three or four valves, and contain sporules; while others are only two-valved, and contain a kind of powder, which some suppose to be pollen, and others abortive sporules. In some of the species, the thecÆ are produced in bracteated spikes, which resemble the young strobiles on a Spruce Fir. The seeds of the common Club-moss (Lycopodium clavatum) are used at the theatres to imitate lightning.

ORDER CCXIII.—MARSILEACEÆ.

These are aquatic herbs, the thecÆ or receptacles of which are always found in the axils of the leaves near the root. In the genus Isoetes (Quillwort) these are of two kinds, like those of the Club-mosses, the one containing powder, and the other granules; but in Pepper-grass or Pillwort (Pillularia), the receptacles are four-celled, and each cell contains both powder and granules. Marsilea, from which the order takes its name, is a native of Italy and other parts of the south of Europe, where it grows in the same manner as Duckweed does with us.

ORDER CCXIV.—EQUISETACEÆ.—THE HORSE-TAIL TRIBE.

The thecÆ of these well-known plants are contained in terminal cone-like spikes or catkins, from four to eight lying in each scale. The stems are tubular, and articulated with whorls of membranaceous sheaths, and of slender branches, jointed, and sheathed like the stem at every joint. All the species of Equisetum abound in silicious matter, and particularly the Dutch Rush (E. hyemale), which is used for polishing both wood and metal. The handsomest species is E. sylvaticum.

ORDER CCXV.—CHARACEÆ.

Aquatic herbs, contained in the genera Nitella and Chara, always growing under water, with slender jointed stems, surrounded at the joints by whorls of tubular leaves or branches, which are either membranaceous and transparent, as in Nitella; or brittle, and more or less encrusted with carbonate of lime, as in Chara, Stonewort. The organs of reproduction are formed in the axils of the branches, and consist of transparent globules, and hard, spiral nuculas, which appear to be formed of twisted leaves, the points of which often form a kind of crest. Young plants are only produced by the nuculas.

ORDER CCXVI.—MUSCI.—THE MOSS TRIBE.

The Mosses have fibrous roots, and slender wiry stems, densely covered with leaves, which are very small, and laid over each other like scales (see a in fig. 149). The theca (g) is urn-shaped, and it is produced singly; in most cases, on a long, slender, wiry stem, called a seta, which signifies a bristle, but sometimes without any stalk. It always springs from a tuft of leaves, differing both in size and shape from ordinary leaves, which form what is sometimes called the perichÆtium. Among these may occasionally be seen a few stalks, resembling the Lichen called Cup-moss, which terminates in a kind of cup, and thickened at the base. The cups and upper parts soon die away, and the thicker part left among the leaves swells, and in time rises on a stalk of its own, carrying away one of the leaves with it on its head. This is the theca, and the leaf it carried away, and which resembles an extinguisher, is called the calyptra, and it remains on till the sporules are nearly ripe. When the calyptra falls, the theca is found to be covered with a little lid called the operculum; which also falls off in time, and shows the mouth or stoma of the theca. This mouth is sometimes naked, and sometimes covered with a kind of film; but generally it is surrounded by a row of long, slender, hair-like teeth called the peristome or fringe. When there are two rows of these hair-like teeth, the inner ones, which are finer than the others, are called the cilia; and the number of both the cilia and the teeth is always some number that can be divided by four. In the cavity of the theca is a central axis called the columella, and around that are found the sporules, kept together by the lining of the theca, which forms a kind of open bag. This is the usual construction of all the numerous genera of mosses; but in some kinds, as for example in the Hair-moss (Polytrichium), in addition to the theca, a number of granules are found among the leaves, which are said to be capable of producing young plants.

ORDER CCXVII.—HEPATICÆ.

These plants greatly resemble Mosses in their appearance, but they differ in their construction. The theca has no lid, but bursts into valves; and it generally contains not only sporules, but tubes formed of curiously twisted threads, called elaters. Jungermannia and Marchantia have a calyptra, which the other genera are without; and in Jungermannia the theca has a sort of sheath, which is sometimes called the calyx. There are also stalked granules called anthers, and warts which form on the leaves, and break up into a kind of sporules.

SUB-CLASS II.—APHYLLEÆ.

ORDER CCXVIII.—LICHENES.

Though these plants are said to have no leaves, they consist almost entirely of a kind Fig.150—Usnea Florida. (Old Trees.) of leafy stem, called a frond or thallus, the branches of which are called podetia (see a in figs. 150, 151, and 152). The spores or sporules are produced in what are called shields (b in Fig.151.—Ramalina fastigiata. (Rocks and Trees.) figs. 149, 150, and 151), which are generally embedded in the thallus, and which, when they are cup-shaped (as in fig. 150), are called scyphÆ, and when flat (as in fig. 151), apothecia. The sporules, which are very numerous, are inclosed in Fig.152.—Cornicularia heteromalla.—(Old Trees.) receptacles of various forms, which are embedded in the shields. Some of the commonest lichens are Usnea florida (fig. 150), and Ramalina fastigiata (fig. 151), both of which are found on old oaks, and are generally called grey moss; and Cornicularia heteromalla (fig. 152) is a brown mossy-looking lichen, often found on the bark. Other more interesting lichens are—the Iceland-moss (Cetraria islandica), the Reindeer-moss (Cenomyce, or Cladonia rangiferina), the Cup-moss (Cenomyce pyxidata), and the Orchil (Rocella tinctoria).

ORDER CCXIX.—FUNGI.

The Fungi are divided into several distinct sections; the most important of which may be called the Mushroom tribe. The largest genus in this division is Agaricus, and the plants belonging to it consist of a stipe, or stalk (c in fig. 149), surmounted by the pileus or cap (d). When the mushroom first appears, the stalk is covered by a thin membrane, called the veil (e), which unites the cap to the lower part; but as the mushroom grows, this veil is rent asunder, and it either entirely disappears, or only a small part of it remains round the stalk, which is called the annulus or ring. Under the cap are the gills or lamellÆ, which are of a dark reddish brown; and attached to these are the thecÆ, containing the sporules or seed. In the common Mushroom (Agaricus campestre), and all the eatable kinds, the gills are pink when the veil breaks, which it does very soon, and they become afterwards nearly black; but in all the poisonous kinds, the veil is longer before it breaks, and when it does so, the gills are pale, and frequently nearly white, without becoming darker; the smell is also quite different. The Mushroom tribe, which includes all the Fungi that carry their sporules in the part above the stem, is divided into two sections, viz., those with caps, like the Mushroom, and those which are slender and entire, but club-shaped in the upper part, like Clavaria helvola, a fungus often found in meadows, which resembles the stamen of an orange-lily.

The Morel tribe includes those Fungi which have their sporules in the stipe, and it is in two divisions; the first of which includes those which, like the Morel (Morchella esculenta), have a pileus, or cap, like a mitre; and the second, those which have the pileus curving upwards, like a cup, as in Peziza. A third tribe includes those which, like Tremella, are of a jelly-like substance; and in a similar manner all the numerous genera are arranged. Among these the most remarkable are the Truffle (Tuber cibarium), which is found buried in the earth, and the curious Fungi called Blight and Mildew, which belong to several different genera, and which appear on the leaves and fruit of other plants.

ORDER CCXX.—ALGÆ.

The Sea-weeds are placed on the extreme verge of the vegetable kingdom; and indeed some of them seem almost to partake of the nature of zoophytes. They can live only where there is abundance of moisture, and many of them, such as the different kinds of Fucus, inhabit the sea; by the waves of which they are torn up from their native beds, and washed on shore by the tides. Others are found in the form of ConfervÆ, or green slime, on the surface of stagnant ponds, or on damp stone or gravel-walks; and others appear to form one of the connecting links between vegetable and animal life, as the joints in which they are produced possess the power of separating from each other, and in their divided state so closely resemble animals, as to puzzle naturalists to know where to place them. The AlgÆ are divided by botanists into three classes; viz., the jointless, the jointed, and the disjointed. The jointless AlgÆ are by far the most numerous; and they comprehend all those broad flat jelly-like substances which are called by the popular names of tangle and dulse on the coast, and which are frequently eaten. To this division belong the kinds of sea-weed that are used for making kelp; those from which iodine is procured; those forming the celebrated Chinese birds’ nests; those sold in the oil-shops under the name of laver; and those used by farmers as manure. The jointed AlgÆ are very inferior in the scale of creation to the first division; but the ConfervÆ (see f in fig. 149) are well known, from the rapidity with which they form a thick green slime, by adhering together on the surface of ditches and cisterns, and in short, wherever there is stagnant water exposed to the open air. The disjointed AlgÆ are generally found among the ConfervÆ; but they are so small, and insignificant in appearance, as, in most cases, entirely to escape notice.