the xerophytic vegetation consists of aloes, mesembryanthemums, crassulas, euphorbias, stapelias, and desert ephemerals, spaced 50 cm or more apart, and becoming very sparse going northwards into bushmanland and, from there, into the kalahari desert. the driest region of the karoo, however, is its southwestern corner, between the great escarpment and the cederberg-skurweberg mountain ranges, called the tankwa karoo, which receives only 75 mm of rain annually. the eastern and north-eastern karoo are often covered by large patches of grassland. the typical karoo vegetation used to support large game, sometimes in vast herds.