BOTANICAL CHARACTERS. 



137 



of planting. The stems vary in height from 20 to 50 inches, 

 and in diameter from 1-16 to 1-8 inch. 



173. The Leaves. As soon as a kernel of wheat germi- 

 nates, it sends out leaves and roots to enable the plant to 

 live after the supply of food in the seed is exhausted. These 

 first leaves come from the lower joints of the stem, and per- 

 form their work during the early growth of the plant. As 

 the stem grows, the leaves on the upper nodes develop and 

 shade the lower leaves so that they wither and disappear. 

 The leaves of 



wheat are alter- 

 nate, one leaf 

 appearing from 

 each joint. The 

 lower part of the 

 leaf, the sheath, 

 clasps the stem 

 nearly the entire 

 length of the 

 interne de. The 

 sheath is split 

 open on the side 

 opposite the leaf Fig. 43. 

 blade, and at the 

 junction of the sheath and blade is a ligule which clasps 

 the stem tightly. The blades are long and tapering; they 

 vary from J^ to % inch in width, and from 8 to 15 

 inches in length. 



174. The Flowers. The flowers of wheat are arranged in 

 a compact terminal spike. The spike is made up of a 

 number of small spikelets, with two or more flowers in each 

 spikelet. These spikelets are arranged alternately on the 

 spike on either side of a central stem or rachis. Each indi- 



At the left, a wheat flower; at the right, a 

 spikelet of wheat in bloom. 



