CEREALS AND FORAGE PLANTS 



355 



The most obvious distinction between wheat and rye is that 

 in wheat each spikelet contains several perfect flowers, while 

 in rye each spikelet contains two perfect flowers. There are 

 many races of wheat, but the conspicuous difference in the 

 heads is that some are " bearded " (with 

 awns) and some are " beardless " (without 

 awns) (Fig. 33). 



58. Discovery of wild wheat. The cul- 

 tivation of wheat is the oldest recorded 

 agricultural operation, and wheat is per- 

 haps still to be regarded as the most valu- 

 able of cereals. The wild original of the 

 wheat was long sought for, and it was sup- 

 posed that it had been so long in cultiva- 

 tion that it must have become very much 

 changed and probably was represented in 

 nature by some inconspicuous grass. It 

 seemed clear that if wild wheat still existed, 

 it would be found in western Asia. A few 

 years ago a Jewish botanist found the wild 

 original of wheat growing upon the rocky 

 slopes of the mountains of Palestine, and 

 it did not look very different from culti- 

 vated wheat. It is clear now that our an- 

 cestors who began the cultivation of wheat 

 did not select an inconspicuous grass, fore- 

 seeing that it might be changed into a very useful plant, but 

 took a grass that was plainly useful already. In fact, this 

 wild wheat is a better plant for our purpose in several par- 

 ticulars than our cultivated races. It grows in thin and dry 

 soils, quite unlike the soil necessary for the cultivated races 

 of wheat, which have become pampered by being transferred 

 to better soils. Not only is this wild wheat drought-resistant, 

 but its vigor is further shown by the fact that it is not sus- 

 ceptible to the attack of the rust disease, one of the most 



FlG. 32. Wheat, show- 

 ing general habit of 

 plant ; the flower 

 cluster is a spike. 



