Grasses also characterize steppes and savannas, where they form scattered tufts.
The rainfall, which also has an important bearing upor the culture of peoples, will be found on the whole to be greatest in the third zone and also in the eastern highlands, and of course least in the desert, the steppes and savannas standing midway between the two.
In the savannas the most characteristic trees are the monkey bread tree or baobab (Adansonia digitata), doom palm (Hyphaene) and euphorbias.
The open savannas are the home of large ungulates, especially antelopes, the giraffe (peculiar to Africa), zebra, buffalo, wild ass and four species of rhinoceros; and of carnivores, such as the lion, leopard, hyaena, &c. The okapi (a genus restricted to Africa) is found only in the dense forests of the Congo basin.
It is extensively distributed in the tropical parts of South and Central America, frequenting low swampy savannas, along the banks of rivers, and the depths of the humid forests, but is nowhere abundant.