South American flora

It has been estimated that some 3,000 plant genera are endemic to South America. The largest vegetation zone in the continent is the tropical rainforest in the north. Moving southwards, the vegetation passes through tall-grass forest, Pampas, and scrub to steppe in the far south. The west coast has a narrow strip of desert; behind this stand the high Andes, whose vegetation changes with altitude and humidity. In the southwest are deciduous forests of beech.

The Caribbean A wide range of valuable plants comes from the Caribbean region, which in many ways is the neotropical counterpart of peninsular Malaysia in Southeast Asia. Plants native to the Caribbean include maize Zea mays, vanilla (from the orchid genus Vanilla), Dahlia variabilis, and poinsettia Euphorbia pulcherrima.

The Amazon This region, with the largest area of tropical rainforest in the world, where the endemic plant species may number as many as 3,000, has provided the world with several important species, particularly the Para rubber Hevea brasiliensis and cocoa Theobroma cacao. The region is famous for one of the world's most majestic plants, the giant water lily Victoria amazonica, named after Queen Victoria. The Amazon rainforest, while not so rich in species as the rainforests of Southeast Asia, is richer than those of Africa. Southern Brazil is exceptionally rich and is the home of a number of well-known plants now cultivated all over the world, including Bougainvillea spectabilis, Passiflora caerulea, and Begonia semperflorens. The most characteristic plant families of the Latin American rainforest formation are the Leguminosae, Meliaceae, Moraceae, Sapotaceae, Euphorbiaceae, Myristicaceae, and Lecythidaceae.

The savannah The term savannah, which is used to describe any tropical grassland with trees, originated in South America. In Brazil, for example, there are scrubby woodlands known as campo cerrado (closed grassland), vast expanses of savannah with scattered trees or patches of forest called campo sujo (dirty grassland), and open grasslands with trees only in the valley bottoms termed campo limpo (clean grassland). There is also, in the drought-affected northeast, a thorny, deciduous woodland called caatinga. A characteristic genus of the Latin American savannahs is Curatella.

Temperate regions The flora of temperate Latin America comprises at least 1,500 genera and over 12,500 species. Several well-known garden plants originated in the Andean region, including Berberis darwinii, Buddleia globosa, and Tropaeolum species. The region is also the home of an extraordinary number of plants of economic importance, including the potato Solanum tuberosum, the tomato Lycopersicon esculentum, and tobacco Nicotiana tabacum. The zonation of vegetation in the Andes is highly distinctive; it includes the northern paramos, a mountain grassland consisting of tall bunch grasses and shrubs, and the central Andean puna, a dry mountain grassland of short grass.

The Mediterranean region The Mediterranean region of Chile has some interesting woodland remnants, with species adapted to dry conditions, such as Lithraea caustica, which causes rashes and fever if touched, and Quillaja saponaria, a source of saponin, used in fire extinguishers. Around Valparaíso there is the palm Jubaea spectabilis, and dry rocky habitats have the large Puya species of the Bromeliaceae and cylindrical cacti. Of particular note in southern Chile and Tierra del Fuego are some 50 genera that are also found in Oceania. Three genera (Acaena, Tetragonia, and Gunnera) are also found in South Africa. The southern beech genus Nothofagus forms beautiful forests in southern Chile, similar to those of New Zealand. Southern Chile also has some interesting coniferous elements, including species of the genera Austrocedrus and Podocarpus, used for their timber, and the monkey puzzle trees Araucaria.

Temperate grasslands The Pampas region, which is one of the world's most important grasslands, covers an area of over 750,000 sq km/290,000 sq mi. In the west, towards the Andes, it is hot and dry, and only prairie grass and thorny bushes grow. The east, towards the Atlantic, receives more rainfall; here the landscape has been affected by human settlement, cattle farming, and introduced trees. The Pampas is not noted for its own distinctive elements, but has a number of predominant elements of wider distribution, such as Larrea divaricata, Prosopis alba, and many grasses and members of the Compositae. Introduced species include the milk-thistle Silybum marianum and the cardoon Cynara carduncellus.

Desert The western slopes of the Andes above the Peruvian-Chilean coastal desert are famous for bromeliads of the genus Tillandsia, whose leaves absorb the water-droplets from condensed fog.