48 



THE CEREALS IN AMERICA 



club wheats are closely related to each other, as are likewise 

 the poulard and durum wheats. Einkorn never, and the polish 

 wheat rarely, gives rise to a fertile cross with common wheat. 

 The subspecies of Tr. sativum readily cross with each other. 

 The relationship of the eight types is shown in the following 

 outline : 



monococciini (i) einkorn 



spelta (2) spelt 



dicoccum (3) emmer 



Triticiint 



sativum — i 



tcnax — 



vulgare (4) common 

 wheat 



compactum (5) club 

 or square head wheat 



turgidum (6) poulard 

 wheat 



durum 



(7) durum 

 wheat 



^polonicum (8) polish wheat 



78. Einkorn {Tr. monococcum L.). — This 

 species may be distinguished from the other 

 species by the palea falling into two pieces at 

 maturity. The joints of the rachis readily 

 separate as in the case of the wild species 

 of this genus. Usually only the lower flower 

 of the spikelet matures. Each spikelet is 

 awned and the spike is compact. The wild 

 type is scarcely distinguished from the culti- 

 vated t)'pe. It is cultivated somewhat in 

 Europe in poor and rough places unsuited foi' 

 other varieties of wheat. Its cultivation is of 

 great antiquity, as is proven by finding the 

 icne.haif natural size.) grain in the Lake dwellings belonging to tha 



Einkorn. 



