EXERCISE 30 

 A STUDY OF THE BARLEY HEAD 



Object. To examine the head of barley and become 

 familiar with the shape and arrangement of its different 

 parts. 



Explanation. The head of barley is commonly called a 

 spike. It is made up of several parts, of which the grain is 

 the most important. The head of barley is composed of a 

 single rachis and several spikelets. The spikelets bear the 

 grain and are attached to the rachis. A spikelet of barley 

 is made up of two outer glumes, a flowering glume, a kernel, 

 and palea. The outer glumes are small and awl-shaped and 

 do not inclose the flowering glume as in wheat and oats. The 

 flowering glume bears the beard or awn when present and 

 incloses the greater part of the kernel. The palea incloses 

 the inner side of the kernel. In most barleys the flower- 

 ing glume and palea adhere to the kernel when threshed. 

 Some varieties of barley, however, are hull-less. In hull-less 

 barleys the flowering glume and palea do not adhere to 

 the kernel. The germ is at the base of the kernel, as in' 

 wheat, and faces outward. The crease is on the inside 

 next to the palea. There are both two-rowed and six-rowed 

 barleys. 



In the six-rowed barleys the spikelets develop in groups of 



124 



