Ave'na sati'va, Oat, N.F. -- The grain with not more than 5 p.c. of other seeds or of foreign organic matter; Asia, Europe. Plant .6-1.3 M. (2-4 degrees) high, culm smooth, leaves linear, veined, rough panicles loose, spikelets 2-3-flowered, paleae (husk) cartilaginous. Grain pale yellow, up to 1.5 Cm. (3/5') long, 3 Mm. (1/8') thick, fusiform, scar at base, apex showing lemma and palet, groove on ventral side having 2-veined palet or scale, straight or slightly twisted awn (strongly twisted -- Wild Oat), caruncle at micropylar end, dense hairs at apex; odor slight; taste starchy. Powder, whitish -- epicarp, pointed hairs fragments of lemma and palet, coarse unicellular hairs, endosperm, starch grains up to .06 Mm. (1/400') broad, polygonal or fusiform individual grains up to .01Mm. (1/2500') broad. Grain composed of husk 25 p.c., grain (kernel) 75 p.c.; the former contains fixed oil 1-1.5 p.c., sugar and gum .25-.75 p.c., proteins 2 p.c.; the latter starch 64-66 p.c., fat 5-7 Oat starch: magnified p.c., proteins 18-21 p.c. (mainly avenin), salts 1-3 p.c. The grains 250 diam. when ground when ground yield -- oatmeal, when deprived of paleae -- groats.
Oatmeal (Farina Avenae) is not uniform, but is yellowish-white, with gluten and husk present, bitterish, starch granules polyhedric, muller-shaped. Demulcent, laxative, dietetic, nutritive; indigestible husks act as a mechanical irritant, exciting peristalsis, but may constipate by compaction; porridge or gruel may ferment and impair digestion. Dose, ad libitum; 1. Fluidextractum Avenae Sativae (33 p.c. alcohol), dose, 3j-2 (4-8 cc.). Prep.: 1. Elixir Hydrastis Compositum, 1.75 p.c.