LESSON VI 



PEDICELED SPIKELETS WITH LARGE GLUMES 

 AND OTHER MODIFICATIONS 



Turning again to the spikelet of Bromus secalinus 

 (Fig. 11), compare with it Fig. 31 (wild oats, 



Avenafatua). The 

 glumes are greatly 

 enlarged and the 

 rachilla joints are 

 so short that the 

 florets appear to 

 be almost oppo- 

 site. The a^vn, 

 instead of extend- 

 ing from the apex 

 of the lemma, pro- 

 trudes from the 

 back and is 

 twisted for about 

 half its length. 

 We noted in Les- 

 son IV that the 

 awn is an exten- 

 sion of the mid- 

 nerve. This fact is well shown in the floret of wild 

 oats (Fig. 31, B, the floret seen from the back), in 



42 



Fig. 31. A, spikelet of .4»eno/o<wa; B, floret. 



