198 FIELD CROPS 



are of a grayish-green color. The head is similar to that of 

 wheat, consisting of a spike with spikelets arranged along a 

 central stem, or rachis. The spikelets are arranged in groups 

 of three alternately at the joints of the rachis, making six 

 rows of grain from the top to the bottom of the spike. The 

 two-rowed appearance of some varieties of barley is due to 

 the fact that only the central one of the three spikelets is 

 fertile and produces grain. Many of the varieties are bearded, 

 or awned; in some, the beard is replaced by a three-forked 

 appendage, or hood. The grain is usually enclosed within 

 the flowering glume, or hull, though some varieties thresh 

 clean like wheat. It is either whitish or bluish black. 



243. Classification. Varieties of barley may be divided 

 into classes along several lines. The first general division 

 into two-rowed and six-rowed forms is based on the fertility 

 or infertility of the lateral spikelets, as stated in the preceding 

 paragraph. Six-rowed barley is of two general forms, the 

 round and the square, of which the square type is the more 

 common. The former is the type usually known as six- 

 rowed, while the square type is often spoken of as four- 

 rowed. The four-rowed appearance is due to a twisting of 

 the lateral spikelets, so that the grain at the left of one 

 group of spikelets is in line with that on the right of the op- 

 posite one, the two rows appearing as one. Two types of 

 two-rowed barley are also grown, one with a short, broad 

 head and the other with a long, slender one; the latter is the 

 common form. Another division may be made on the pres- 

 ence or absence of awns, or beards, the classes then being 

 known as bearded and hooded, or beardless. Still other 

 classes are the common, or hulled, and the naked, or hull-less, 

 the division being made according to the manner in which 

 the grain threshes from the head. 



As with wheat, there are winter and spring forms. Win- 

 ter barley is less hardy than winter wheat, but more so than 

 winter oats. The winter varieties usually grown are of the 



