OAT (O. Eng. āte; the word is not found in cognate languages; it may be allied with Fr. eitel, knot, nodule, cf. Gr. οἶδος swelling), a cereal (Avena sativa) belonging to the tribe Aveneæ of the order Gramineae or grasses. The genus Avena contains about fifty species mostly dispersed through the temperate regions of the Old World. The spikelets form a loose panicle, familiar in the cultivated oat (fig. 1),
Fig. 1.—Panicle of Oat, Avena sativa. (After Le Maout.)the flowering glume having its dorsal rib prolonged into an awn (fig. 2), which is in some species twisted and bent near the base.
The origin of the cultivated oat is generally believed to be A. fatua, or “wild oat,” or some similar species, of which several exist in southern Europe and western Asia. Professor J. Buckman succeeded in raising “the potato-oat type” and “the white Tatarian oat” from grain of this species. A. strigosa, Schreb, “the bristle-pointed oat,” is the origin of the Scotch oat, according to Buckman. The white and black varieties of this species were cultivated in England and Scotland from remote times, and are still grown as a crop in Orkney and Shetland. A. strigosa is probably only a variety of the cultivated oat. The “naked oat”, A. nuda, was found by Bunge in waste ground about Peking; it was identified by the botanist Lindley with the pilcorn of the old agriculture and we see from Rogers[1] that it was in cultivation in England in the 13th century. Both this and the “common otes,” A. vesca, are described by Gerard.[2] Parkinson tells us that in his time (early in the 17th century) the naked oat was sown in sundry places, but “nothing so frequent” as the common sort. The chief differences between A. fatua and A. sativa, are, that in the former the chaff-scales which adhere to the grain are thick and hairy, and in the latter they are not so coarse and are hairless. The wild oat, moreover, has a long stiff awn, usually twisted near the base. In the cultivated oat it may be wanting, and if present it is not so stiff and is seldom bent. The grain is very small and worthless in the one, but larger and full in the other. There are now many varieties of the cultivated oat included under two principal races—common oat or panicled oats with a spreading panicle, A. sativa proper, and Tatarian oats or banner oats which has sometimes been regarded as a distinct species, A. orientalis, with contracted one-sided panicles. With regard to the antiquity of the oat, A. de Candolle[3] observes that it was not cultivated by the Hebrews, the Egyptians, the ancient Greeks and the Romans. Central Europe appears to be the locality where it was cultivated earliest, at least in Europe, for grains have been found among the remains of the Swiss lake-dwellings perhaps not earlier than the bronze age, While Pliny alludes to bread made of it by the ancient Germans. Pickering also records Galen’s observations (De Alim. Fac. i. 14), that it was abundant in Asia Minor, especially Mysia, where it was made into bread as well as given to horses.
Besides the use of the straw when cut up and mixed with other food for fodder, the oat grain constitutes an important food for both man and beast. The oat grain (excepting the naked oat), like that of barley, is closely invested by the husk. Oatmeal is made from the kiln-dried grain from which the husks have been removed; and the form of the food is the well-known “porridge.” In Ireland, where it is sometimes mixed with Indian-corn meal, it is called “stirabout.” Groats or grits are the whole kernel from which the husk is removed. Their use is for gruel, which used to be consumed as an ordinary drink in the 17th century at the coffee-houses in London. The meal can be baked into “cake” or biscuit, as the Passover cake of the Jews; but it cannot be made into loaves in consequence of the great difficulty in rupturing the starch grains, unless the temperature be raised to a considerable height. With regard to the nutritive value of oatmeal, as compared with that of wheat flour, it contains a higher percentage of albuminoids than any other grain, viz. 12·6—that of wheat being 10·8—and less of starch, 58·4 as against 66·3 in wheat. It has rather more sugar, viz. 5·4—wheat having 4·2—and a good deal more fat, viz. 5·6, as against 2·0 in flour. Lastly, salts amount to 3·0% in oat, but are only 1·7 in wheat. Its nutritive value, therefore, is higher than that of ordinary seconds flour.