130 FUNDAMENTALS OF AGRICULTURE. 



of the leaf and which varies in length, width, shape, 

 hairiness, and shape and prominence of veins; (2) the 

 sheath which in all plants of the grass family encloses 

 the stem tightly and is split down the side of the stem 

 opposite the leaf blade; upon removing the sheath 

 from any internode of the culm while the plant is 

 green and growing, the culm underneath will be found 

 white and tender; (3) the ligule, a thin tissue-like 

 guard or band which forms the connecting line between 

 the blade and the sheath and which clasps the stalk 

 tightly; this together with the (4) auricles, other thin 

 projections of leaf tissue which are at the junction of 

 the leaf and sheath, and which are at either side of 

 the upper end of the sheath act as a rain and dust 

 guard, thus preventing these from getting in between 

 the sheath and the internode which it envelops. 



The Head (panicle). A typical oat head usually 

 contains from three to five whorls of small branches, 

 each in turn bearing from three to five florets or spike- 

 lets. Each floret is at the end of a limber pedicel 

 which is of such variable length as to form a head 

 which may appear very compact or one that may be 

 equally open. Each floret is composed of two or 

 more flowers, but it is seldom that more than two 

 flowers mature. 



Of these two flowers that normally mature the 

 lower invariably forms the larger grain. This large 

 grain usually bears an awn, although the length and 

 persistence of this awn varies greatly with the differ- 

 ent varieties of oats. When but a single flower ma- 

 tures the oats are known as " single " oats, but when, 

 as is usual, two flowers mature, the oats are known as 

 " twin " oats. The entire panicle varies in length, 

 but will usually average about ten inches. 



The general shape and structure of the oat grain 

 is similar to that of wheat, rye and barley, except that 

 it is more elongated, has a hairy pericarp, and remains 

 enclosed in its hull (flowering glume and palea). 

 The per cent, of hull on oats depends on conditions of 



