types:
oat
annual grass of Europe and North Africa; grains used as food and fodder (referred to primarily in the plural: `oats')
barley
a plant cultivated since prehistoric times, grown for forage and grain
rice
annual or perennial rhizomatous marsh grasses; seed used for food; straw used for paper
Secale cereale,
rye
hardy annual cereal grass widely cultivated in northern Europe where its grain is the chief ingredient of black bread and in North America for forage and soil improvement
millet
any of various small-grained annual cereal and forage grasses of the genera Panicum, Echinochloa, Setaria, Sorghum, and Eleusine
wheat
annual or biennial grass having erect flower spikes and light brown grains
Indian corn,
Zea mays,
corn,
maize
tall annual cereal grass bearing kernels on large ears: widely cultivated in America in many varieties; the principal cereal in Mexico and Central and South America since pre-Columbian times
corn
(Great Britain) any of various cereal plants (especially the dominant crop of the region--wheat in Great Britain or oats in Scotland and Ireland)
panic grass
any grass of the genus Panicum; grown for grain and fodder
sorghum
economically important Old World tropical cereal grass
soft wheat
wheat with soft starch kernels used in pastry and breakfast cereals
field corn
corn grown primarily for animal feed or market grain