Flora of USA varies according to climatic zones. One-third of the country covered with forests. In southern Alaska - vast coniferous forests, the rest of the state is covered mostly with tundra mosses and lichens. The central part of the country is characterized by a mixed forest vegetation: spruce, pine, oak, ash, birch, magnolias. Cedar, pine and larch forests are typical of the north east coast. To the south the vegetation becomes a subtropical nature: there are magnolias, rubber. Gulf Coast is covered by mangrove vegetation. The western part of the country - a region of deserts and semi-deserts. Here, the most characteristic species - yucca, shrubs, and shrubs. In the desert, many varieties of cacti and succulents. In California, a very common chaparral, citrus fruits, various palms. Sierra Nevada - the edge of giant Sequoias.