Erou.k. The vegetation of Africa is very di versified on :1(.4.4)11111 of the well-marked topo graphic districts and the varied climatic condi tions. The three zones of tropical, north tem perate, and south temperate (climate have their peculiar types of vegetation. the distribution of which in each zone is determined by the imme diate physiographie features. Forest, steppe, savanna, and desert floras are found in each zone. The flora of the :Mediterranean slope of the northern temperate zone has a general re semblance to that of southern Europe, with for ests of oak and of smaller trees, as olives and figs. with also the vine and the same cereal grains. The desert region; (typified by the Sahara in the north temperate zone and the Kalahari Desert in Bechuanaland of the south temperate zone) support a seant xerophytic vegetation, which, contrasted with the flora of the North American deserts, has for its most prominent types quite leafless. thorny and fleshy cuphorbias and acacias instead of cactuses. In the Sahara Desert the date palm grows often in groves in the oases, and it. \ride dis tribution is probably duo in large part to the dispersion of its seeds by the nontadie tribes, for whom its fruit serves as an important article of food. Bordering the Sahara and the Kalahari deserts are extensive semi-arid slept)e or prairie regions, where the slight rainfall permits of the existence of a SollieWhal more Varied flora, which combines certain of the desert and forest types, The steppe region of the southern temperate zone has. by reason of its isolation, developed a
flora peculiarly its own, which is eharaeterized both by the abundant presence of many members of the heath family I which often grow to a height exceeding DI feet I, and also by the general bril liancy of color of the flowering plants.
Those portions of Africa which have )t moist climate are divisible into the savanna and forest regions. The forests are found mostly in the equatorial districts, Where they are of enor mous extent. the trees grow to great heights (often •00 feet), and, being close to gether, support numbers of parasit h. vines. form ing over vast areas a dense, tangled covering of foliage, through which the direct rays of the sun seldom The savanna districts are uniform plains of both high and low land. On the damp lowlands, reeds, especially the papyrus, abound (as, for example, in the marshy regions of the Nile and Congo valleys) ; on the drier high groumls good pasture grass with euphorbias forms the dominant vegetation, together with forest growths in the river valleys. The more im portant trees art' the baobab (Adansonia) and the wine and oil palms (Raphia and Ekris). In conelusion, it, may by stated that the flora of Africa is characterized by the develop ment of acacias and cuphorbias over the entire eontinent. with the date palm in the northern tpartienlarly in the arid) regions, and the papy His ill the IllarslieS. See DI STI:111CTION (IF PLANTS.