grass

Grass is the common word that generally describes monocotyledonous green plants.  The family Poaceae (or Gramineae) 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 recognized to be grasses, such as bamboos, maize or some species of weeds called crab grass.