CLASSIFICATION OF ANGIOSPERMS. 



227 



propagated ; the culms vary from one to four feet in height, the 

 spikelets are 3- to /-flowered; and the empty glumes, 5- to 

 7-nerved, acute or with an awn-hke apex. 



Hordeum sativum is an annual grass with the flowers in ter- 

 minal cylindrical spikes resembling wheat. The spikelets are ses- 

 sile, I -flowered, and usually in clusters of three on opposite sides 

 of the notched rachis. The empty glumes are long and narrow, 



Fig. 125. Wheat (Triticum): A, zigzag axis or rachis of ear showing the notches 

 where the spikelets were inserted; B, an entire spikelet; C, j flower with the pales; D, a 

 flower without the pales, showing the lodicules at the base; E, glume; F, outer pale; G. 

 inner pale; H, fruit icaryopsis); I, longitudinal section of fruit. After Warming. 



forming a kind of involucre around the spikelet. It is supposed 

 that Hordeum sativum is a cultivated form of H. spontancum 

 growing in the countries between Asia Minor and other parts of 

 Western and Southwestern Asia. Three important varieties are 

 distinguished depending upon the number of rows of grains in 

 the ear. H. sativum distich on includes the plants having 2- rowed 

 ears and these are chiefly grown in Middle Europe and England. 



