In some places in the wooded sections pineapples are very abundant, and seem to be as well established as in their native soil in tropical America.
In the tropics, wherever a broad belt of alluvial soil is exposed by the fall of the tide, as on the shores of the sea, in the estuaries of rivers, and in the shallow lagoons, we may expect to find a dense vegetation of mangroves.
These water-loving trees seem to seek the salt water sections in preference even to other localities equally damp. Their growth is peculiar and picturesque. The seeds germinate on the branches, increase to a considerable length, and then fall into the mud. Here, with their sharp points lying buried, they soon take root.
As the mangrove grows upwards, roots issue from the trunk and low branches, and ultimately strike into the muddy ground, where they grow and present the appearance of a series of loops and arches, from five to ten feet high, which support the body of the tree like so many stakes.
Their matted roots interrupt the flow of the waters, and by retaining the earthy particles that sink to the bottom between them, gradually raise the level of the land. As the new land is thus built up, seeds begin to grow in it, and thousands of roots descend, still further to consolidate it. Thus, year after year, the mangroves extend the land into the sea.
As we approach the southern portion of the great peninsula of Africa, we find a wilderness of sand. This barren tract occupies the central portion of the country. Here there is little or no vegetation to attract the eye.
In the table-lands of Cape Colony there are numerous fleshy, leafless tribes of aloes and other plants. These fix their hold in the sand by means of a single tough, wiry root. For conveying nourishment to the plants, these roots must be practically useless, since the soil affords little food. Hence the main sustenance of these plants must come from the dews with which a wise Creator supplies their needs. Many varieties of heath are found here, among other plants.
Upon the hills and rocks of some sections of Africa is a curious tribe of plants which seem partly of the nature of palms and partly of the nature of ferns. They may be said to be of an intermediate family. These fernlike palms literally cover the hills and rocky slopes. After a rain, such portions of the country as have been watered by nature's hand blossom forth into indescribable beauty; for the gladiolus, oxalis, and other native plants are in brilliant bloom.
At Cape Town the American aloe tree has been introduced, and vast impenetrable hedges have been formed by the interlacing of its spinelike leaves, which are often six feet in length. Here, too, flourish the oak and pine of Europe, for the climate is most favorable to their growth.
We have had occasion to speak of the thick-leaved, cactuslike plants of the desert, which seem to prefer the arid soil of the naked plains, where they are fully exposed to the burning rays of a tropical sun.