Grass is the common word that generally describes monocotyledonous green plants. The family Gramineae (Poaceae) are the "true grasses" and include most plants grown as grains, for pasture, and for lawns (turf). They include some more specialised crops such as lemongrass, as well as many ornamental plants. They also include plants often not recognized to be grasses, such as bamboos or some species of weeds called crab grass.
Use of the term
The term grass is often used to describe related plants in the rush (Juncaceae) and sedge (Cyperaceae) families, that somewhat resemble grass. It may also be used to describe completely unrelated plants, sometimes of similar appearances to grass, with leaves rising vertically from the ground, and sometimes of dissimilar appearance. The term came about in the early 15th century, from the Old English gr￦s, derived from the same root as "grow". A single piece of grass is called a blade.
Grass-like plants are among the most versatile life forms. Plants having grass-like structures have existed for millions of years, providing fodder for Cretaceous dinosaurs, whose fossilized dung (coprolite) contains phytoliths of a variety of grasses that include the ancestors of rice and bamboo. Grasses have adapted to conditions in lush rain forests, dry deserts, and cold mountain steppes, and are now the most widespread plant type.
Plants of this type were always important to humans. They were cultivated as food for domesticated animals for up to 10,000 years. (See grass fed beef.) They have been used for paper-making since at least 2400 BC. Now they provide the majority of food crops, and have many other uses, such as feeding animals, and for lawns. There are many minor uses, and grasses are familiar to most human cultures.
In some places, particularly in suburban areas in the United States and Canada, the maintenance of a grass lawn is a sign of a homeowner's responsibility to the overall appearance of their neighborhood. Many municipalities and homeowner's associations have rules about this. Some require lawns to be maintained to certain specifications, sanctioning those who allow the grass to grow too long. In communities with drought problems, watering of lawns may be restricted to certain times of day or days of the week.
Grass is also used in several contexts in sports, most notably with sports played on fields such as football, cricket, baseball, and rugby. In some sports facilities, including indoor domes and places where maintenance of a grass field would be difficult, grass may be replaced with artificial turf, a synthetic grass-like substitute. Sports such as cricket, golf and tennis are particularly dependent on the quality of the grass on which the sport is played.
A cricket pitch often starts with a thin cover of green blades, but over the course of a five-day match tends to dry out and harden. Even in one-day matches cricket pitches are often nearly bare earth covered only by a layer of dry yellow stalks.
A green or moist pitch favours the bowler, as it varies the bounce of the ball and increases its movement. A hard, dry pitch gives a more predictable, higher bounce which favours the batsman. The nature of the outfield is also important, as grass may slow down a ball, causing it to stop before reaching a boundary or allowing a fielder more time to gather the ball. Laws 10 and 11 of cricket detail maintenance and protection of the pitch. Unlike test cricket and One Day International, indoor cricket is played on an artificial surface.
In tennis, grass is grown on very hard-packed soil, and bounces may vary depending on the grass's health, how recently it has been mowed, and the wear and tear of recent play. The most famous grass tennis court in the world is Centre Court at Wimbledon. But tennis is usually played on clay courts, and only a few regular tennis tournaments are played on grass. The surface is softer than hard courts, so the ball bounces lower, and players must reach the ball faster. Grass courts are now rare as they must be watered and mowed often, and take longer to dry after rain than hard courts.
Golf, on the other hand, is usually played on grass, and is dependent on the maintenance of a very large area of well-cut grass. Grass on golf courses is kept in three distinct conditions: that of the rough, the fairway, and the putting green. Grass on the fairway is short and even, allowing the player to cleanly strike the ball. Playing from the rough is a disadvantage because the grass is generally much longer, which may affect the flight of the ball. Grass on the putting green is the shortest and most even, ideally allowing the ball to slide smoothly over the surface. An entire industry revolves around the development and marketing of grasses for golf courses.