PEDICELED SPIKELETS 



31 



so far (and in all but a very small number of 

 grasses) the bracts above the lower pair are flower- 

 bearing or have a palea, which indicates their struc- 

 tural identity. Corresponding parts in a modified 

 spikelet are, therefore, regarded as lemmas. In the 

 grass just examined the sterile spikelets remain on 

 the panicle branches after the fall of the ripened 

 fertile florets from their glumes. 



In Fig. 22, A (Achy r odes 

 aureum), is shown a fascicle 

 of one fertile and three 

 sterile spikelets of another 

 grass. In this the fascicles 

 hang from the short slen- 

 der branches of a narrow 

 panicle and disarticulate 

 from them, falling entire. 

 This is the first example we 

 have had so far of disartic- 

 ulating branches of the in- 

 florescence. In the figure 

 the fascicle is seen from the 

 inner face to show the fer- 

 tile spikelet, which from 

 the outside is nearly hid- 

 den by the sterile ones. Fig. 22, B, shows a sepa- 

 rate fertile spikelet. It will be seen that except 

 for the glumes, the two forms are strikingly dif- 

 ferent. The fertile spikelet is reduced to one 

 fertile and one rudimentary floret, both awned, 



FIG. 22. A, fascicle of three sterile 

 and one fertile spikelet of 

 Achyrodes aureum; B, fertile 

 spikelet. 



