The Amazon River basin has an area of almost 7 million square kilometers (2.7 million square miles), making it the largest watershed in the world. River Basins South America has three important river basins: the Amazon, Orinoco, and Paraguay/Paraná. The heavily forested plateau of the Guiana Highlands covers southern Venezuela, French Guiana, Guyana, northern Brazil, and a portion of southeastern Colombia. The Guiana Highlands are located between the Amazon and Orinoco Rivers. Located south of the Amazon River in Brazil, the Brazilian Highlands are made up of low mountains and plateaus that rise to an average elevation of 1,006 meters (3,300 feet). Outside the Andes, South America has two principal highland areas: the Brazilian Highlands and the Guiana Highlands. The leaves of this endangered species all grow from one woody stem, allowing moisture to run down the leaves to the base of the plant.
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A Puya raimondii can live for 100 years and can grow to more than 9 meters (30 feet) tall. The largest herb in the world, Puya raimondii, is known as the Queen of the Andes. Most plants in the alpine biome are small, and their leaves are stiff and strong to protect them from frost and drought. The Patagonia region of Argentina and Chile consists of lower-elevation plateaus and rugged glaciers. The altiplano of Peru and Bolivia, for example, has an elevation of about 3,700 meters (12,300 feet). High plateaus are also a feature of the Andes. Aconcagua is the tallest mountain outside Asia. The highest peak in the Andes, Aconcagua, stands at 6,962 meters (22,841 feet) and straddles the Argentina-Chile border. There are hundreds of peaks more than 4,500 meters (15,000 feet) tall, many of which are volcanic. Situated on the far western edge of the continent, the Andes stretch from the southern tip to the northernmost coast of South America. The range covers about 8,850 kilometers (5,500 miles). Mountains & Highlands South America’s primary mountain sy stem, the Andes, is also the world’s longest. With an unparalleled number of plant and animal species, South America’s rich biodiversity is unique among the world’s continents.
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One of the continent’s river basins (the Amazon) is defined by dense, tropical rain forest, while the other (Paraná) is made up of vast grasslands. Within a few hundred kilometers, South America’s coastal plains’ dry desert biome rises to the rugged alpine biome of the Andes mountains. A biome is a community of animals and plants that spreads over an area with a relatively uniform climate.
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South America’s extreme geographic variation contributes to the continent’s large number of biomes. Mountains and coastal plains generally run in a north-south direction, while highlands and river basins generally run in an east-west direction. South America can be divided into three physical regions: mountains and highlands, river basins, and coastal plains. South America’s physical geography, environment and resources, and human geography can be considered separately. South America, the fourth-largest continent, extends from the Gulf of Darién in the northwest to the archipelago of Tierra del Fuego in the south.