SPIKELETS WITH HARDENED FRUITS 



69 



all but the two lower florets. The result is compara- 

 ble to the two florets (Fig. 60, C) of Panicum, but 

 in this genus the lower floret is staminate or sterile, 

 and its lemma and palea differ in form and texture 

 from those of the perfect floret (Fig. 60, D). The 

 sterile lemma (commonly termed the "third glume" 

 in all but recent books) resembles the second 

 glume and incloses a small thin palea, while the 



Tf" 



Fig. 60. A, spikelet of Panicum miliaceum, side view; B, same 

 seen from the back; C, sterile and fertile florets removed 

 from the glumes, side view; D, fertile floret. 



fertile lemma is indurate, its nerves obscured in the 

 thickened tissue, and firmly clasps a palea of like 

 texture. At maturity the grain is inclosed in this 

 fast-locked little case (the whole commonly termed 

 the fruit) and germinates within it, sending its rootlet 

 through a thin place near the base of the lemma 

 (seen as a crescent-shaped depression at the back) 

 and thrusting its sprout between the lemma and 

 palea at the summit or side. In dissecting a spikelet 

 of Panicum or its related genera the palea of the 



