14 THE DESCRIPTION" OF WHEAT VARIETIES. 



Awns. — The terms long, medium, and short arc only comparative^ 

 as are the terms slender, medium, and stout. The terms orderly, 

 medium, and irregular, and parallel, spreading, and spreading widely 

 apply to the way the awns stand in relation to the head. Orderly is 

 used when the awns are uniform in length or position, and irregular 

 when some of them are long- and others short or when some are par- 

 allel to the spike and others twisted or divergent. Deciduous, j>"/-fly 

 deciduous, and persistent apply to the way the awns are retained after 

 the plant reaches maturity. Some plants normally have awns so 

 brittle that they break at the point of juncture with the flowering 

 glume soon after the plant reaches maturity. 



The color terms again are relative. 



Spikelets. — The terms spreading widely, spreading, and narrow apply 

 to the width of the spikelet, or the way the glumes are set. Plate IV 

 shows extreme cases of the width of spikelets. The number of grams 

 per spikelet means the number of grains borne in an average well- 

 developed spikelet. 



The structure of the spikelet and the shape of the various glumes 

 are of such importance in describing wheat varieties that they deserve 

 special attention. The spikelet is composed of several flowers borne 

 alternately on a short branch of the spike called the rachilla, and sub- 

 tended by two large bracts, or outer, empty glumes. These glumes are 

 hereafter railed the outer glumes and should not be confused with the 

 flowering glume which surrounds each flower or grain. The long awns 

 of the spike, when present, are borne on the flowering glumes. The 

 outer glumes never bear awns longer than two or three centimeters. 



In Plate V, fig. 13, is shown a spikelet split apart to show the rachilla 

 and the way the glumes are borne, and in the same plate (fig. 19) is 

 shown the compound spikelet found in the so-called Mummy wheat, 

 or Seven- headed wdieat. In the latter case the spike is branched and 

 each branch, in turn, bears true spikelets. 



There is usually borne on the rachis at the base of each spikelet, 

 below the outer glumes, a growth of shor,t, bristly hairs (PI. IV. fig. 

 1) which are here called basal hairs and which may be described by 

 the terms long, medium, short, and wanting, and in color either whiti 

 or brown. These hairs should not be confused with the hairs some- 

 times present on the outer glumes. 



The outer glume may be either hairy, partly hairy, or smooth. Plate 

 VII, figs. 4 and 6, shows types of hairy and smooth glumes, while in 

 Plate V, fig. 14. is shown a^pikelet of which not only the outer glumes 

 are hairy but also the flowering glumes as well. The terms glossy, 

 medium, and dull apply to the surface of the outer glume, as do the 

 terms uniform in color and streaked. 



The terms broad, nodi an,, and nat^row apply to the shape of the 

 outer glume: that is. to the way the wings on either side of the keel 



