GraminecB.] iGEAMlNEiE. 405 



Axis bearing several empty shortly awued glumes 

 above the fertile flower. 



Spikes digitate 39. Chloris. 



Spikes distant, iu a long panicle 44. Lophatherum. 



Flowering glumes andpalea small, very thin and trans- 

 parent. 

 Spikelets singly sessile or indented. 



Spikelets scarcely indented in the axis ; 2 stiff 



outer glumes 35. Microchloa. 



Spikelets indented in the axis ; 1 hard outer glume 13. Opmiurus. 

 Spikelets indented in the axis in pairs, 1 sessile, the 

 other pedicellate. 



Both spikelets l-flowered, fertile 14. Hemarthria. 



Sessile spikelet with a second male flower ; pedi- 

 cellate one reduced to a rudimentary glmue , 28. Ischjjmum. 

 Spikelets mostly unisexual. 



Spikelets in a simple spike, the upper ones male, the 



lower fertile 9. Thouarea. 



Spikelets dioecious, the males in clustered spikes, the 



females solitary amidst clustered bracts .... 8. Spinifkx. 

 Spikelets with a twisted a\vn proceeding from the flowering 

 glume. 

 Spikelets singly sessile or accompanied by a rudimentary 

 pedicel. 



Glumes acute 17. Dimeria. 



Outer glumes broad and truncate 23. Apocopis. 



Spikelets in pairs, 1 sessile, the other pedicellate. 

 Both spikelets fertile and awned. 



Fertile flower solitary in each spikelet 21. Pollinia. 



One fertile and 1 male flower in each spikelet , .29. Spodiopogon. 

 Sessile spikelet fertile and awned ; pedicellate one male 

 and awnless or rudimentary. 

 Fertile flower alone in the sessile spikelet . . . .25. Andropogon (n. 1 and 2). 

 One fertile and 1 male flower iu the sessile spikelet 28. Isch^mum. 

 Sessile spikelets female, cylindi'ical, awned ; pedicellate 



ones larger, flat, and awnless. (Pedicel very short) 26. Heteropogon. 

 3. Spikelets or spikes more or less pedicellate in an irregular or spreading panicle. 

 Spikelets singly pedicellate, awnless or with a straight or 

 rarely twisted awn. 

 Two empty glumes besides the flowering one. 



Flowering glume and palea hardened over the grain and 

 not longer than the second outer one. 

 Spikelets awnless, ovoid-oblong, resting on a callous 



base 3. Eriochloa. 



Spikelets awnless or with a fine awn, narrow, with- 

 out a callous base 11. Garnotia. 



Flowering glume convolute, with 3 awns. Spikelet 



narrow 32. Aristida. 



Flowering glume awnless, longer than the outer glumes. 



Grain uncovered 80. Sporobolus. 



Three glumes besides the floioering one, all empty or the 

 third with a male flower. 

 Two flowers fertile (or at least with hardened glumes) 



in most spikelets 7. Isacune. 



One flower in each spikelet fertile, with a coriaceous 

 glume and palea. 

 Palea ciliate, with long spreading hairs. Spikelets 



minute 12. Thysanol^na. 



