With latitudinal limits comparable to those between Havana and Hudson Bay, and elevations ranging from oceanic to alpine, Argentina possesses a diversity of flora. Much of it will be novel to foreign visitors, especially those from the northern hemisphere.
Floral associations are strongly, but not perfectly, correlated with latitude and altitude. The environments below are described in more detail in the listings for individual national parks and other locations in the destination chapters.
As European sheep, cattle, and horses consumed the succulent native grasses of the pampas, they so impoverished the native vegetation that opportunistic colonizers like thistles turned much of the region into a botanical desert. As the land grew too valuable for grazing, grain farms supplanted the livestock industry in many areas.
Dense, nearly impenetrable forests still cover large areas along the banks and on the islands of the Paraná, the Uruguay, and other northern rivers. Twisted trunks of the ceibo (whose blossom is Argentina’s national flower) mix with sauces (willows), canelones, and lesser species.
Argentina has no truly tropical rain forests, but Misiones Province  is a panhandle of verdant subtropical forest jutting northeast between Paraguay and Brazil; araucaria pines punctuate its interior uplands. On the most easterly Andean slopes, in Salta, Jujuy, and Tucumán Provinces, the yungas are a narrow longitudinal fringe of cloud forest with a unique microclimate.
Between these two geographical extremes, the Gran Chaco of Formosa, Chaco, and Santiago del Estero Provinces is a mix of broad savannas and dense thorn forests. Away from the rivers, yatay palm savannas survive on the higher ground of Entre Ríos.
In the canyons of the northwest, the dry hillsides sprout stands of the cardón cactus; at higher altitudes, these yield to broad level areas of the perennial bunch grasses ichu, interspersed with shrubs known collectively as tola. Their sparse vegetation provides year-round pasture for wild guanacos and vicuñas, and domestic llamas and sheep.
In the Patagonian lakes district, various species of broad-leafed southern beech (Nothofagus spp.), both evergreen and deciduous, are the most abundant trees. There are, however, several notable conifers, particularly the pewen or paraguas (umbrella, Araucaria araucaria), so named because its crown resembles an umbrella. It’s also known as the monkey-puzzle tree because its limbs seem to take the shape of a monkey’s curled tail. The long-lived alerce or lawen (Fitzroya cupressoides) is an endangered species because of its high timber value, though most stands of the tree are now protected.
Note that Argentines other than specialists refer indiscriminately to conifers as pinos (pines), even though the southern hemisphere has no true pines (of the genus Pinus) other than garden ornamentals or timber species in plantations.
In the rain shadow of the Andes, on the eastern Patagonian plains, Chilean Magallanes, and even parts of Tierra del Fuego, decreased rainfall supports extensive grasslands where the wind blows almost ceaselessly. In some areas, thorn scrub such as the fruit-bearing calafate (a barberry) is abundant. From the late 19th century, sheep-grazing for wool had a tremendous detrimental impact on these natural pastures.
From southern Patagonia to the tip of Tierra del Fuego, Argentine woodlands consist primarily of dense southern beech (Nothofagus) forests that, because of winds and climatic extremes, are nearly prostrate except where high mountains shelter them.