The grass family is of very great importance.  The cereal grasses, e.g., wheat, rice, corn, oats, barley, and rye, provide the grain that is the staple food of most of mankind and the major type of feed. The grasses also include most of the hay and pasture plants, e.g., sorghum, timothy, bent grass, bluegrass, orchard grass, and fescue. Popularly the word grass is used chiefly for these latter and for the lawn grass types; it is also loosely applied to plants which are not true grasses (e.g., clover and alfalfa) but which are similarly grown.

       

Sugarcane is another very important grass.  Plants of the grass family are also a source of industrial ethyl alcohol, corn starch and byproducts, newsprint and other types of paper, and numerous lesser items. Especially in the tropics, species of reed, bamboo (one of the few woody types), and other genera are used for thatching and construction. As food, grasses are as important for wildlife as for domesticated animals. They are able to survive grazing because their intercalary meristems are set back from the apex of the plant. Because of the tenacious nature of their large underground root system, grasses  often prevent erosion.