oats, cereal plants of the genus Avena of the family Gramineae (grass family). Most species are annuals of moist temperate regions. The early history of oats is obscure, but domestication is considered to be recent compared to that of the other grains—perhaps c.2500 B.C. During the Bronze Age, the time when horses were first used as draft animals, oats were widely grown in N Europe but were apparently still uncultivated by the civilizations around the Mediterranean. They have a high nutritive value, but of the oats now grown commercially, less than 5% is for human consumption, chiefly in the form of rolled oats or oatmeal for breakfast foods; they do not contain the glutenous type of protein necessary for making bread. The chief value of oats remains as a pasturage and hay crop, especially for horses. Oats are valuable also in crop rotation and have various industrial uses. Oat hulls are a source of furfural, and oat flour has been used as a food preservative in ice cream and other dairy products. Oat straw is preferred by farmers for animal bedding. Diseases such as cereal rusts and smuts (see diseases of plants) cause a heavy annual crop loss, but disease-resistant varieties of oats are being developed. Oats rival corn and wheat as a leading grain crop in the United States (the country of highest production), Canada, N Europe, and the countries of the former Soviet Union. The common cultivated species ( A. sativa ), native to Eurasia, is no longer found growing wild. Like wheat, it is broadly classified into spring and winter types, depending upon the season of planting. Oats are classified in the division Magnoliophyta, class Liliopsida, order Cyperales, family Gramineae.