148 BOTANY OF CROP PL.A^^TS 



long. The rachilla is broom-form or very hairy. The noted 

 malt barley. Chevalier, belongs to this t>'pe. 



Origin of Cultivated Barleys. — There are two principal 

 opinions regarding the origin of cultivated barley, that of 

 Koernicke and that of Rimpau. Koernicke considers Hor- 

 deum spontaneum to be the prototype of all our cultural 

 forms. This wild barley is nearest related to the nutans 

 form of two-rowed barley, being distinguished from the 

 latter by its more fragile rachis, less compressed spike, 

 stronger awns, larger side spikelets, perennial habit, and its 

 stronger tendency to tiller. The variety nutans first arose 

 from the wild form. From this came erectum, by a shorten- 

 ing of the rachis joints. From erectum, came zeocriton by 

 still greater shortening of rachis joints, and an enlargement 

 of the fruit toward the base. From nutans also, there arose 

 the four-rowed barley, by the side spikelets becoming 

 fertile. From erectum and zeocriton, there came sLx-rowed 

 barleys. 



Rimpau, on the other hand, considers the six-rowed 

 bearded barley as the prototv-pe of all other barley tjpes. 

 Through a process in which side spikelets become rudimen- 

 tary, there arose the various four- and two-rowed tx-pes. 

 Rimpau bases his opinion on the nature of the offspring 

 between zeocriton and trifurcatum. 



Environmental Relations. — Winter barleys are less resist- 

 ant to winter cold than either "w-inter wheat or winter rye. 

 Consequently, in the Northern States practically all barley 

 is spring-sown. As a spring-sown crop it has a wide geo- 

 graphical range. It is grown as far as 65° X. latitude in 

 Alaska, and to an altitude of 7,500 feet in the Rocky Moun- 

 tains. At higher elevations it is grown as a hay, the chief 

 variety being "bald barlev. " Bqiey also does well in 

 southern Cahfornia. 



