31 



5. Bristles thickened or connate below, becoming hard and bur- 

 like 26. Cencheus 



5. Bristles not connate below, usually slender and often plumose. 



27. Pennisetum 



6. Glumes, including the flowering, two, usually acuminate- 



pointed 18. Reimaria 



6. Glumes more than two 7 



7. Glumes three 8 



7. Glumes four 10 



8. Spikelets with an enlarged annular callus at the base, flowering 



glume mucronate or short awn-pointed 22. Eriochloa 



8. Spikelets without an annular callus at base; flowering glume 



awnless 9 



9. Spikelets in loose terminal panicles 20. Anth^exantia 



9. Spikelets sessile or very short pedicelled, in one-sided spikes or 

 ■ racemes 19. Paspalum 



10. First glume usually smaller than the others (rarely wanting) , 



awnless 23. Panicum 



10. First and second, and sometimes also the third, glumes awned. 



24. Oplismexus 



