Grasslands go by many names. In the U.S. Midwest, they're known as prairies. In South America, they're called pampas. Central Eurasian grasslands are referred to as steppes, while in Africa they're named savannas. What they all have in common is grass as their naturally dominant vegetation. Grasslands are found where there is not enough regular rainfall to support the growth of a forest, but not so little as to form a desert.