CHAPTER XXXVII. 



CULTIVATED BARLEYS (Genus Hordeuin). 



I. Characters of the Genus. — The inflorescences or ' ears ' are 

 spike-like and consist of many groups of three single-flowered 

 spikelets (Fig. 159) arranged from top to bottom of an elongated 

 rachis. 



Each spikelet appears practically sessile on the rachis ; but 

 a triplet of single-flowered spikelets really represents a primary 

 branch with two opposite lateral 

 branches each bearing one 

 flower. The rachilla on which 

 the spikelet grows laterally is 

 prolonged and appears as a 

 small bristle - like structure, 

 readily seen with a lens, lying 

 within the ' furrow ' of a barley 

 grain as in Fig. 163. 



The groups of spikelets are 

 arranged alternately at notches 

 on opposite sides of the rachis, 



Fig. isg. — A^ Piece of rachis of six-rowed 

 barley showing a triplet of single-flowered 

 pikelets, r Rachis of the ear ;tf empty glume; 



so that the whole ear appears to 7floweri'nggi'_ 



have six longitudinal rows of .hfwin'gTtri^^o/Llle^rw^red^i'eS 

 flnu/prt: ^'^ central flowtr fertile, the two lateral 



liuwci s. flowers (a) imperfect, r Rachis of the car ; e 



The empty glumes («, Fig. ?J^P(J;^,'")'^° i,^''™'""^ ^'"""^ '' " ™''"" 

 159) are very narrow and stand 



side by side in front of the flowering glume. The latter is 

 broad and possesses a long awn which acts as a transpiring 

 organ. The longest awns are usually attached to the largest 



