Cereal grains provide more than one half of the total calories consumed by man. Not only humans, but also domestic animals are fed primarily by cereal grains. Society as we know it could not exist without cereal grains. The only places that cereal grains are not too important is in a few areas of the lowland tropics, and in high Andean areas.
Grasses also are among the oldest of cultivated crops.
They were used long before that. Wheat and barley sustained the Near Eastern cultures, rice the Far East, corn the pre-Columbian New World cultures, and sorghum a number of African ones. The one seeded fruit has a seed coat fused with the ovary wall. There are at least 9000 species of grasses. The seeds of most are edible, although some are infected with endophytes and fungi.