Caatinga is a type of desert vegetation, and an ecoregion characterized by this vegetation in interior northeastern Brazil. The name "Caatinga" is a Tupi word meaning "white forest" or "white vegetation" . Caatinga is a xeric shrubland and thorn forest, which consists primarily of small, thorny trees that shed their leaves seasonally. Cacti, thick-stemmed plants, thorny brush, and arid-adapted grasses make up the ground layer. Many annual plants grow, flower, and die during the brief rainy season. Caatinga falls entirely within earth's Tropical zone and is one of 6 major ecoregions of Brazil, including the Amazon Basin, Pantanal, Cerrado, Caatinga, Atlantic Forest, and Pampas. It covers 850,000 km², nearly 10% of Brazil's territory. It is home to 26 million people and more than 2000 species of vascular plants, fishes, reptiles, amphibians, birds, and mammals.