<Li> The rest of the Kalahari is subject to the maritime trade winds, that largely shed their moisture as they cross up and over the Southern African Great Escarpment before arriving over the Kalahari . </Li> <P> There are huge subterranean water reserves beneath parts of the Kalahari; the Dragon's Breath Cave, for example, is the largest documented non-subglacial underground lake on the planet . Such reserves may be in part the residues of ancient lakes; the Kalahari Desert was once a much wetter place . The ancient Lake Makgadikgadi dominated the area, covering the Makgadikgadi Pan and surrounding areas, but it drained or dried out some 10,000 years ago . It may have once covered as much as 120,000 square kilometres (46,000 sq mi). </P> <P> The Kalahari has had a complex climatic history over the past million or so years, in line with major global changes . Changes in the last 250,000 years have been reconstructed form various data sources, and provide evidence of both former extensive lakes and periods drier than now . During the latter the area of the Kalahari has expanded to include parts of western Zimbabwe, Zambia and Angola . </P> <P> 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). </P>

Describe the climate and vegetation of kalahari desert