180 THE TRUE GRASSES. 



bluut or toothed apex ; flowering glumes rounded on the 

 back, often navicular, many-nerved, ending in -one to 

 several teeth or awns ; fruit very slightly compressed 

 laterally, deeply sulcate, hairy at the apex, free. Em- 

 bryo with epiblast and three rootlets. Always annual. 



Two illy denned sections : 



Sec. I. JEgilops L. (as a genus). Empty glumes flat 

 or rounded on the back, not at all, or indistinctly, 

 keeled. 



Species twelve, in Southern Europe and the Orient 

 to Afghanistan and Turkestan. JE, ovata L. with 3-5 

 awns on the empty glumes, JE. triuncialis (Fig. 94), three 

 awns, etc., in Southern Europe ; the former forms a cross 

 with T. sativum. The spikes fall off as a whole, separat- 

 ing below the lowest fertile spikelet ; the empty glumes 

 of several Oriental species are one-awned or awnless and 

 the spikelets fall off singly. These form transitions to 

 the following section. 



Sec. II. Sitopyros. Empty glumes sharply keeled. 

 To this section belong the most important grains. They 

 can be traced back to three species. 



a. Terminal spikelet aborted, often scarcely visible. 

 Palea falling into two parts at maturity. Lateral 

 teeth of empty glumes acute. . 1. Tr. monococcum. 



b. Terminal spikelets developed ; palea remaining en- 

 tire ; lateral teeth of the empty glumes obtuse. 



a. Empty glumes shorter than any of the flowering 

 glumes, chartaceous; palea as long as flowering 



glumes 2. Tr. sativum. 



ft. Empty glumes as long as or longer than any of the 

 flowering glumes, chartaceous, lanceolate ; palea 

 of the lowest flower half as long as its glume. 



3. Tr. Polonicum. 



1. Tr. monococcum L. (Fig. 103). Spikes compact, 

 articulate, joints readily separating (even in cul- 

 tivated forms), every spikelet with one awn ; 

 usually only the lower, very rarely also the 

 upper, flowers maturing their fruit. The wild 

 plants (Tr. Bceboticum Boiss., Crithodivm a'cjilo- 

 poides Link) scarcely distinguished from the 



