190 THE TRUE GRASSES. 



barley (Fig. 105). Spikes roundish in circumfer- 

 ence ; all six rows diverging uniformly and forming 

 a six-rayed star when viewed from above ; joints of 

 rachis very short, therefore the spikelets are closely 

 imbricated. Very widespread, even in prehistoric 

 times (Lake dwellings), but at present it is culti- 

 vated only in Southern Europe, rarely in Switzer- 

 land and in Germany, 

 c. H. sat. vulgare (H. vulgare L.), irregularly ranked or 

 four-rowed barley (Fig. 106). Spikes dorsally com- 

 pressed ; the middle row more appressed to the 

 rachis than the irregular rows of the lateral spike- 

 lets ; spikes loose, often nodding. This race seems 

 to be of later origin. Its variety pallidum (with 

 pale yellow spikes) is the barley most frequently 

 cultivated in Northern Europe (Norway to 78°) and 

 Northern Asia. It is usually raised as a summer 

 grain, and its period of vegetation may be limited 

 to ninety days. In Central Europe, where its cul- 

 ture was earlier introduced, it is becoming gradu- 

 ally supplanted by the two-rowed, and especially 

 by the Chevalier barley. The greater amount of 

 gluten which it contains makes it less adapted for 

 beer-brewing ; besides, on good soil the produce 

 of the two-rowed is greater than that of the four- 

 rowed, while the latter surpasses it on poor land. 

 The variety ccerulescens, with the gray spikes, is 

 more frequently cultivated in Southern Europe 

 and Northern Africa. A special series of varieties 

 is formed by the naked-fruited barleys (H. cceleste 

 L.) as well as the Himalaya barleys, among which 

 is the remarkable hereditary malformation (H. 

 trifurcatum) with three-horned flowering glumes. 

 Between the four-rowed, six-rowed, and two-rowed 

 barleys are transition stages (e.g., var. intermedium 

 Korn, and H. Kavfmanni Regel), in which all the 

 spikelets are fertile but the lateral ones are awn- 

 less. These are spontaneous variations and not 

 crosses, for the majority of barlej-s, especially the 

 six-rowed, bear cleistogamic flowers, so that a cross 

 in the open air is impossible. 



