Botswana and 30°E. The country is predominantly flat, tending toward gently rolling tableland. Botswana is dominated by the Kalahari Desert, which covers up to 70% of its land surface. The Okavango Delta, one of the world's largest inland deltas, is in the northwest. The Makgadikgadi Pan, a large salt pan, lies in the north. The Limpopo River Basin, the major landform of all of southern Africa, lies partly in Botswana, with the basins of its tributaries, the Notwane, Bonwapitse, Mahalapye, Lotsane, Motloutse and the Shashe, located in the eastern part of the country. The Notwane provides water to the capital through
Kalahari Desert latter the area of the Kalahari has expanded to include parts of western Zimbabwe, Zambia and Angola. Due to its low aridity, the Kalahari supports a variety of flora. The native flora includes acacia trees and many other herbs and grasses. The kiwano fruit, also known as the horned melon, melano, African horned cucumber, jelly melon, or hedged gourd, is endemic to a region in the Kalahari Desert (specific region unknown). Even where the Kalahari "desert" is dry enough to qualify as a desert in the sense of having low precipitation, it is not strictly speaking a desert because it