Grasses family of Gramneae, are the most variable, widespread and useful plant goups and comprise more than 600 genera and 7500 species. The soft, velvety turf plants that form lawns bear little resemblance to the huge, woody bamboos towering 40 m (132 ft) or more in height. Submerged aquatic plants growing in the sea seem quite different from the small, tender shoots emerging from a snowback in the alpine tundra above the timberline. Yet all these may be grasses.
To the average urban dweller, grass may mean only the green carpet covering a lawn or courtyard. To a farmer in the Great Plains, on the other hand, grass cereal grains such as wheat may be the major cash crop. Grasses produce the bulk or forage for the world’s livestock industry, and they provide building materials for houses in tropical areas.
Grasses grow on all continents. They are found in the sea, in freshwater marshes, in deserts, above the treeline on high mountains, and in arctic areas. In some regions grasses constitute the dominant vegetation type. As a group, grasses are among the most successful and actively evolving of all plants. Their great flexibility and adaptability permit them to live in most situations. Their adaptive that compete with understory in forest and savanna, and horizontally spreading perennials that form either dense sod or loose ground cover.