The
vegetation of
Africa follows very closely the distribution of heat and moisture. The northern and southern temperate zones have a
flora distinct from that of the continent generally, which is tropical. In the countries bordering the
Mediterranean, there are groves of
orange and
olive trees, evergreen
oaks,
cork trees and
pines, intermixed with
cypresses,
myrtles,
arbutus and fragrant
tree-heaths. South of the
Atlas Mountains, the conditions alter. The zones of minimum rainfall have a very scanty flora, consisting of plants adapted to resist the great dryness. Characteristic of the
Sahara is the
date palm, which flourishes where other vegetation can scarcely maintain existence, while in the semidesert regions the
acacia, from which gum arabic is obtained, is abundant. The more humid regions have a richer vegetation; dense forest where the rainfall is greatest and variations of temperature least, conditions found chiefly on the tropical coasts, and in the west African equatorial basin with its extension towards the upper
Nile; and
savanna interspersed with trees on the greater part of the plateaus, passing as the desert regions are approached into a scrub vegetation consisting of
thorny acacias, etc. Forests also occur on the humid slopes of mountain ranges up to a certain elevation. In the coast regions, the typical tree is the
mangrove, which flourishes wherever the soil is of a
swamp character. The dense
forests of
West Africa contain, in addition to a great variety of
hardwoods, two
palms,
Elaeis guineensis (oil palm) and
Raphia vinifera (bamboo palm), not found, generally speaking, in the savanna regions.
Bombax or silk cotton trees attain gigantic proportions in the forests, which are the home of the India rubber-producing plants and of many valuable kinds of timber trees, such as odum (
Chlorophora excelsa),
ebony,
mahogany (
Khaya senegalensis),
Oldfieldia (
Oldfieldia africana) and
camwood (
Baphia nitida). The climbing plants in the tropical forests are exceedingly luxuriant and the undergrowth or "bush" is extremely dense. In the savannas the most characteristic trees are the monkey-bread tree or baobab (
Adansonia digitata),
doum palm (
Hyphaene) and
euphorbias. The
coffee plant grows wild in such widely separated places as
Liberia and southern
Ethiopia. The higher mountains have a special flora showing close agreement over wide intervals of space, as well as affinities with the mountain flora of the eastern
Mediterranean, the
Himalaya and
Indo-China. In the swamp regions of north-east Africa,
papyrus and associated plants, including the soft-wooded
ambach, flourished in immense quantities, and little else is found in the way of vegetation. South Africa is largely destitute of forest, save in the lower valleys and coast regions. Tropical flora disappears, and in the semi-desert plains the fleshy, leafless, contorted species of kapsias,
mesembryanthemums,
aloes and other succulent plants make their appearance. There are, too, valuable timber trees, such as the
yellowwood (
Podocarpus elongatus),
stinkwood (
Ocotea),
sneezewood or
Cape ebony (
Pteroxylon utile) and ironwood. Extensive miniature woods of heaths are found in almost endless variety and covered throughout the greater part of the year with innumerable blossoms in which red is very prevalent. Of the grasses of Africa, alfa is very abundant in the plateaus of the Atlas range. ==Fauna==