42 



PANICACE.E. 



Subgenus 5. Sorghum (Pers. as a genus). Spikelets truly and 

 conspicuously paniculate, rays j slender, tlie lateral in pairs. 



consisting of a sessile fertile 

 one on a pedicel, the branches 

 pedicellate spikelets. First and 

 spikelets coriaceous. 



one and a staminate or abortive 

 terminating in 1 sessile and 2 

 second glumes of the fertile 



Fig. 14.— Spikelets of A. Eallii. 



a. Kays of the panicle verticellate ; the pedicellate spikelets 



staminate with 4 glumes, rarely 1-2 and neuter. . . .26 



a. Eays of the panicle mostly solitary, but branching near the 



base (b) 



b. Pedicellate spikelets none or sometimes reduced to 



pedicels merely (c) 



c. Panicle oblong, erect or nodding 27 



c. Panicle secund, rays variously flexuose 28 



Subgenus 6. Chrysopogon (Trin. as a genus). Eacemes 

 whorled, pedicellate, spikelets obviously paniculate and laterally 

 compressed. Our single species is a tall annual; the awns 12-15 



cm. long 29 



Subgenus 7. DiciiANTiiirM (Willemet as a genus). Spikes 



