LESSON X 



SPIKELETS WITH MEMBRANACEOUS GLUMES 

 AND HARDENED FRUITS 



All the spikelets heretofore studied have been 

 more or less compressed laterally (that is, a detached 

 spikelet under observation lies on its side, the two 

 ranks of glumes and lenmias to right and left of the 

 rachilla, as in Figs. 11-14) and, with relatively few 

 exceptions, the articulation has been above the 

 glumes, these remaining on the pedicel after the fall 

 of the florets. These two characters in common 

 pertain to more than half of all our grasses. In 

 many of the laterally compressed spikelets the 

 florets themselves are dorsally compressed (see 

 Fig. 11, B). We come now to a lesser group, in 

 which the spikelets are dorsally compressed (the 

 spikelet under observation lying on its face or back, 

 the two ranks above and below the rachilla). In 

 this group of grasses the rachilla joints are usually 

 so short that the glumes and lemmas are borne one 

 immediately above the other. The rachilla is never 

 prolonged beyond the base of the fertile floret, as in 

 many of the spikelets heretofore studied. 



Examine Fig. 60. Note that the first glume is 

 much smaller than the second. Turn to Fig. 11 

 (page 25). In imagination, remove the glumes and 



68 



