Prairie

A prairie is a natural vegetation type in which perennial herbaceous plants predominate, particularly species of grasses. The word "prairie" comes from the French prérie (later, prairie), meaning meadow. The term was first applied to the swath of mid-continental North American grassland in the 1600s by French Jesuit missionaries and explorers, because the landscape resembled, on a much vaster scale, the familiar agricultural meadows of western Europe. Thus, geography and nomenclature came together to distinguish the North American prairie from similar grasslands elsewhere in the world: the steppes of central Asia, the pampas of South America, and the veldt of southern Africa.

Until the settlement era, the central prairie of North America stretched from southern Alberta, Saskatchewan, and Manitoba south to mid-Texas, and from the foothills of the Rocky Mountains eastward into Indiana. It covered about 1.4 million sq mi (3.6 million sq km). Outlying patches occurred in Ohio, Michigan, Kentucky, and southwestern Ontario. A similar vegetation type went under the names of "plains" or "downs" in the northeastern United States.

The general trend toward increasing rainfall and increasingly rich soil from west to east in mid-continental North America gave rise to a descriptive classification of the prairie. Its western edge, on the high plains, became known as shortgrass prairie, because shorter grasses grew on its generally poorer and drier soils. A transitional zone running north to south along the ninety-eighth meridian, through Alberta, Saskatchewan, the Dakotas, Nebraska, Kansas, and Oklahoma, became known as mixed-grass prairie. The richest, eastern sector, which bulged eastward from the ninety-eighth meridian through Illinois and into northwestern Indiana, became known as the tallgrass or "true" prairie. This scheme gradually evolved into the one used by modern biologists to classify prairies, which takes into account soil, bedrock, and vegetation types and has many divisions. The tallgrass prairie is the major subject of this article.

A native prairie is sprinkled with brilliantly colored flowers of broadleafed (or dicotyledonous) plants that A tall grass prairie during a Montana summer. © Barry Griffiths, National Audubon Society Collection/Photo Researchers, Inc. Reproduced with permission. often exceed the height of the grasses. Some prairie grasses attain a height of 6.6 ft (2 m), and sometimes more, if soil and moisture conditions are favorable. Early settlers' descriptions of grasses taller than a person on horseback were probably exaggerated and reflected a tradition of romanticizing the landscape. Intermixed with the predominant grasses are broad-leaved plants called forbs, which lend color and diversity to the vegetation. Besides the grasses (family Poaceae), such as little and big bluestem and Indian grass, common prairie plants are species of legumes (Leguminosae), or flowering peas and clovers, and composites (Asteraceae), such as sunflowers, goldenrods, black-eyed susan, asters, and coneflowers.