Oat (Ang. Sax. ata, a word which formerly meant food), a grass of the genus arena., ana especially the cultivated arena satira, the common oat. The genus, which is the type of a sub-tribe of grasses, the aveneoe, has a pan-iclcd inflorescence, with its spikelets several-flowered, the glumes large and exceeding the florets; the lower palet many-nerved, two-cleft at the acute tip, and bearing a long, usually bent or twisted awn on the back below the cleft; grain oblong-linear, grooved on one side, hairy at the top, or sometimes entirely, surrounded by the upper palet, but not adherent to it. The cultivated oat is an annual, but the genus contains perennial species. As with other cereals, the wild state of the cultivated oat is not known, though it is not unlikely that it is a form of the wild oat produced by cultivation. The oat is especially a northern grain, reaching its greatest perfection in cold climates, and in southern countries rapidly degenerating. The heavy seed brought from the north of England and Scotland to this country gives a much lighter grain than the original. The legal bushel of oats in the different states and territories varies from 30 to 35 lbs., the majority having it fixed at 32 lbs.; some of the imported oats weigh from 40 to 50 lbs. the measured bushel.

The varieties are numerous, but seedsmen do not offer more than half a dozen. There are white and black varieties, and those with and without awns. A very popular variety in both England and this country is the potato oat, a large, plump, white grain, so called because it was derived from a stalk found in a potato field; the black Poland is another esteemed variety, and new ones are offered every year. Oats succeed on a great diversity of soils, and in this country they need to be sowed as early as the ground can be worked, that their growth may not be checked by hot weather; from two to four bushels of seed are sown to the acre, and the crop is harvested when the grain has passed the milk state. Oats are more generally used as food for animals in this country than in any other. They consist of 22 to 28 per cent, of husk; the larger and plumper the grain, the less refuse. Deprived of their integuments, oats are called groats or grits, and the Embden and other groats are the same crushed to various degrees of fineness.

Oat meal is prepared by grinding the kiln-dried grain; its composition, as determined by Letheby, is: nitrogenous matter, 12.6; carbohydrates, 63.8; fatty matter, 5.6; mineral matter, 3; water, 15. Oats are regarded as less nutritive than wheat, but their content of nitrogenous principles is rather larger and of carbonaceous somewhat less than in that grain. The skinless oat, a different species from the common one, is A. nuda of Europe; it has narrower and somewhat roughish leaves, three or four florets in each spikelet, and the grain quite loose in the upper palet. This is much esteemed in Ireland and some other parts of Europe, but its culture has not been successful in this country, and the same may be said of other real or supposed species. The entire production of oats in the United States returned by the census of 1870 was 282,107,157 bushels. The states producing more than 5,000,-000 bushels each were as follows: Illinois, 42,780,851 bushels; Pennsylvania, 36,478,585; New York, 35,293,625; Ohio, 25,347,549; Iowa, 21,005,142; Wisconsin, 20,180,016; Missouri, 18,578,313; Minnesota, 10,678,261 Michigan, 8,954,466; Indiana, 8,590,409; Virginia, 6,857,555; and Kentucky, 6,620,103. - The wild oat of Europe and that of California are the same, A. fatua; this has a very loose panicle, with the inner palet and also the grain clothed with long stiff hairs, especially toward the base, and the outer palet also hairy with a stout awn, twice its own length, bent about the middle and twisted near the base; the hairy florets with long awns have the appearance of an insect.

This oat occurs in all parts of Europe as a weed in cultivated fields, and in California it occupies wide tracts of country to the exclusion of other plants, and plays an important part in agriculture. It is of little value for its grain, but when cut before it has begun to ripen it makes valuable hay. The experiments of Prof. J. Buckman at the royal agricultural college, England, show that this may be the original of the cultivated oat; he found that seeds of this gathered when ripe, and sown the next spring, produced plants bearing grain different from those from self-sown seeds; and by continuing this and carefully selecting he in a few years produced grain undistinguishable from that of some cultivated varieties. - The animated oat (A. sterilu) is a native of Barbary, and its seeds are sold by the seedsmen; it has remarkably long, strong, and much twisted awns, bent at right angles. The two-flowered spikelets show two awns and appear wonderfully like an insect. The awns are exceedingly hygrometric, and with the changes of moisture in the atmosphere twist and untwist; when the seed falls and comes in contact with the moist earth, it is enabled to travel quite a distance by the propulsion given to it by the twisting and untwisting of the awns.

If a spikelet of this oat be moistened and laid upon a table, its motions are so life-like as to cause great amusement. Several years ago so-called barometers were sold in which a hand attached to an awn of this oat was moved to point to "rainy," "clear," etc.; but of course it was not a barometer, but only a poor hygrometer. - About 70 species of avena are enumerated, only two of which are natives of this country (A. striata and A. Smithii), and they have no economical value. A. pra-tensis, the perennial oat, and A. flavescens, the yellow oat, are common in the pastures of Europe. Oat grass (arrhenatherum avenaceum) is much like an oat, but has its lower floret staminate only; it belongs to the same sub-tribe with avena, and was formerly called A. elatior. It is a native of Europe, and was introduced to our farmers 50 years ago with the absurd name of Andes grass; it is again receiving the attention of farmers.

Wild Oat (Avena fatua).

Wild Oat (Avena fatua).