The other primary division of vegetable organisms consists of all plants with flowers, and is termed PHANEROGAMIA, and is subdivided into two sections,[23] very unequally numerous. To the first section of phanerogams—a section containing comparatively few kinds—belong all firs, pines, yews, junipers, araucarias, and a most remarkable African plant, Welwitschia, which has never more than two leaves, though these attain enormous dimensions. All these plants are collectively spoken of as conifers, or Coniferæ. Besides these, certain curious southern forms called Cycads are also associated in this section. To this section, thus composed of conifers and cycads, the name Gymnosperms is given, from the naked mode of development of their young seeds. These gymnosperms are also characterized by having such peculiar and inconspicuous flowers that the ordinary observer would hardly apply that term to denote their floral organs.
All the plants which yet remain to be noticed, and which belong to the second and very much larger section of the Phanerogamia are spoken of as Angiosperms. Their seeds are, from their first appearance, in a very different condition from those of gymnosperms, and their flowers are generally conspicuous. To this group, therefore, belong all the familiar ornamental plants of our gardens, and all the brightly coloured natural ornaments of our fields, as well as a number of herbs and trees, the flowers of which, though truly flowers, are not commonly recognized as such.
This group of Angiospermous flowering plants is divided into a great number of natural groups or "orders." Of these there are about 275, and they are grouped in two sets or classes, which are separated one from another, as we shall hereafter see, by differences as to their modes of growth, the structure of their seeds, the numbers of the parts of their flowers, and the course of the veins in their leaves.
First amongst the Angiospermous flowering plants may be mentioned the grasses forming the order Gramineæ, including under that term the tree-like bamboos (of multitudinous uses), with the rice plant, and all the grain-bearing herbs, all of which are grasses. Thus, with much reason may it be said of man, that "all flesh is grass;" for with the exception of the piscivorous Esquimaux, the exclusively flesh-eating Gouchos, the population of Australia, and the people of the Molluccas who nourish themselves on sago—which is the produce of a palm—with these and a few more exceptions, the staple food of the human race is one or another form of grass. It is, indeed, a remarkable fact that men of such varied races so widely spread should have thus selected as their food objects so little tempting in appearance, and so small and so inconspicuous as the seeds of grasses!
Allied to the grasses are the sedges (forming the order Cyperaceæ), and the rushes (Juncaceæ). The apparently insignificant, but really interesting duckweeds (Pistiaceæ) should also be noted with the bullrushes (Typheæ), and the arums (Aroideæ). This last-mentioned order, familiar to us by the kind known as "Lords and Ladies," presents some climbing forms in tropical countries. Generally acrid, some species, when in flower, even produce headache and vomiting; at least an explorer was attacked with these symptoms after gathering forty specimens of Arum dracunculus. The order is also interesting from experiments as to vegetable heat, which have been made with the flowers of some of its species.
The screw-pines (Pandanaceæ) are not "pines" at all, any more than "pine-apples" are pines. They are, indeed, trees or shrubs, which, from one point of view, may be regarded as gigantic bulrushes. The flowers of certain species are in some places eaten as the solid equivalent of a love potion. Allied to the plants of the last-mentioned order are the palms (Palmaceæ), which are the first really large trees we come to after leaving the tree-ferns and the gymnosperms. Amongst the more noteworthy palms may be mentioned the palmetto (Chamærops) of Southern Europe (a summer ornament of our public gardens), the date palm, the areca palm, the sago palm, the cocoa palm, the rattan palm—a natural cordage—and Seaforthia, so remarkable for its graceful and elegant form.
Next may be enumerated the great order of lilies (Liliaceæ), to which the homely and useful onion, leek, garlic, chive, and asparagus belong, no less than a multitude of lovely flowers.
The New Zealand flax (Phormium tenax), and all the magnificent yuccas and aloes, together with our English butcher's broom (Ruscus aculeatus), which has not a little botanical interest (as being the only British shrub which belongs to the group called "Monocotyledons") also belong to this order. Closely allied to the lilies are the amaryllids (Amaryllidaceæ), amongst which are the agaves, with their gigantic flower stems, sometimes forty feet high, supporting a multitudinous crop of flowers, the product and termination of a life.
To these follow the pine-apples (Bromeliaceæ) all originally from America, the useful bananas and plantains (Musaceæ), and the ginger-plants (Zingiberaceæ), tropical herbs, generally of great beauty.
The underground parts of certain tropical plants (Dioscoreaceæ) are known as "yams." A representative of this order exists in England in the climbing black bryony (Tamus) of our hedges, and to the same group belongs the very singularly stemmed elephant's foot, or tortoise-tree (Testudinaria elephantipes). The last-named plant is a native of the Cape of Good Hope, where it has been known as Hottentot's bread, because the soft interior of its swollen base was at one time eaten by the natives of that region, who have, however, now abandoned it to the baboons.