4. 



* 



Fig. 83. 



DIAGRAMMATIC SUMMARY OF THE PRIMARY 

 CHARACTERS OF THE TRIBES 



SERIES I.— POAT.E 



Spikelets laterally compressed; florets mostly falling from the 



persistent glumes 



1. Festuce^e, fescue tribe 



Spikelets many-flowered. 

 Glumes relatively small. 

 Lemmas awned from summit 



or awnless. 

 Inflorescence a panicle. 



[Contains fescues, brome- 



grasses, and blue-grass.] 



2. Horded, barley tribe 



Spikelets 1- to many-flowered, 



sessile on opposite sides of a 



jointed rachis, forming a 



spike. 

 Rachis rather than spikelets 



specialized. 

 Inflorescence a solitary spike. 



[Contains wheat, rye, and 

 barley.] 



3. Avenem, oat tribe 

 Like Festuceae, but glumes en- 

 larged and florets fewer in 

 number. 

 Rachilla joints short. 

 Lemmas awned from the back. 

 Inflorescence a panicle. 

 [Contains oats.] 



95 



Fig. 84. 



Fig. 85. 



