GR AMINES. 467 



SERIES A. PANICA'CE M. Spikelets jointed upon the pedicel below the lowest 

 glumes ; rachilla not jointed at the base nor produced beyond the upper- 

 most glume, persistent. Glumes 4 or fewer, the terminal only bearing a 

 2-sexual flower, rarely a lower one bears an imperfect flower. 



TRIBE I. PANICE'JE. Spikelets dorsally compressed (laterally in Spar- 

 tina). Fl. glume 3- or more-nerved, not awned, hardening round the 

 fruit. (See 11, Mibora in Agrostidese.) 



Glumes 4. Pedicels of spikelets naked or hairy 1. Panicum. 



Glumes 4. Pedicel of spikelets with stiff bristles 2. Setaria. 



Glumes 3. Style long. Spikelets laterally compressed 3. Spartiua. 



TRIBE II. ORYZE'.ffi. Spikelets laterally compressed. Empty glumes 

 minute or 0. Fl. glume and palea 1-nerved or keeled 4. Leersia. 



SERIES B. POA'CE^E. Spikelets rarely jointed upon the pedicel below the 

 lowest glume (except Alopecurus, Polypogon, and Holcus) ; rachilla 

 jointed at the base above the (usually 2) lowest flowerless glumes, often 

 produced beyond the uppermost glume, and deciduous. Glumes 3 or 

 more, 2 lowest flowerless and often persistent (Nardus has no empty 

 glumes ; and all but the uppermost spikelet in Lolium have only one 

 lowest empty glume). 



TRIBE III. PHAIiARIDE'JE. Spikelets laterally compressed; rachilla 

 not produced beyond the uppermost glume. Glumes 6, uppermost 

 only with a 2-sexual flower. Palea or in the perfect flowers 

 1-nerved. 



Glumes 6, 3d and 4th imperfect, not awned. Stamens 3 5. Phalaris. 



Glumes 6, 3d and 4th empty, awned. Stamens 2 6. Anthoxanthum. 



Glumes 6, 3d and 4th awned, triandrous ; 5th diandrous....7. Hierochloe. 



Glumes 3 or 4. Spikelets jointed on the pedicel 8. Alopecurus. 



TRIBE IV. AGROSTIDE'.ffi. Spikelets terete or laterally compressed ; 

 rachilla produced or not beyond the fl. glume. Glumes 3, flower solitary 

 2-sexual ; palea 2-nerved. 



* Rachilla not produced beyond the fl. glume. 



Panicle effuse. Fl. glume hardening round the fruit 9. Milium. 



Panicle dense, cylindric. Fl. glume enclosing the fruit 10. Phleum. 



Spikelets dorsally compressed in a simple subdistichous spike. 



11. Mibora. 



Panicle loose. Fl. glume small hyaline 12. Agrostis. 



Panicle contracted. Empty glumes awned 13. Polypogon. 



Eachilla with long silky hairs 14. Calamagrostis. 



** Rachilla produced beyond the fl. glume. 

 Empty glumes large, boat-shaped ; fl. glume minute, 4-toothed 



15. Gastridium. 



Empty glumes large ; fl. glume 2-fid, awned 16. Apera. 



Empty glumes large ; fl. glumes awned, rachilla ciliate 17. Deyeuxia. 



Spikelets large, rachilla long silky 18. Ammophila. 



Empty glumes plumose ; fl. glume 3-awned 19. Lagurus. 



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