92 



POACEAE 



Tribe IV. Paniceae 



Spikelets without a subtending involucre of bristles or 

 valves. 

 Spikelets all alike. 



Fruiting scale chartaceous, the margins hyaline and 

 flat. 

 Spikelets in slender racemes, borne towards 



the summit. 

 Spikelets in an open panicle on long pedicels. 

 Fruiting scale indurated, the margins inrolled and 

 not hyaline. 

 Spikelets plano-convex, in secund racemes, usu- 

 ally of 3 scales. 

 Spikelets unequally bi-convex, in panicles, 

 rarely in secund racemes. 

 Scales or some of them awned; fruiting 



scale cuspidate. 

 Scales awnless. 



Second scale like the third, few 



nerved, not broad and saccate. 

 Second scale unlike the third, 11-13 

 nerved, broad, saccate. 

 Spikelets of 2 kinds, one paniculate and infertile, the 

 other subterranean and fertile. 

 Spikelets with an involucre 

 Of bristles, persistent. 

 Of 2 spine-bearing valves, enclosing the spikelets. 



10. Syntherisma. 



11. Leptoloma. 



12. Paspalum. 



13. EcHINOCHLOA. 



14. Panicum. 



15. Sacciolepis. 



16. Amphicarpon. 



17. Chaetochloa. 



18. Cenchrus. 



Tribe V. Oryzeae 



Spikelets unisexual; plants monoecious; tall aquatic grasses. 

 Spikelets all perfect. 



Tribe VI. Phalarideae 

 Third and fourth scales 



Small and empty, or rudimentary, not awned ; stamens 3. 

 Empty, awned upon the back; stamens 2. 

 Subtending staminate flowers; stamens 3; fertile flower, 

 stamens 2. 



Tribe VII. Agrostideae 



Flowering scale indurated at maturity, firmer than the 

 empty scales. 

 Spikelets with no basal callus; flowering scale awnless, 



margins inrolled. 

 Spikelets with a basal callus; flowering scale awned, the 

 margins flat. 

 Awn simple. 



Flowering scale broad, the awn deciduous; 



callus short, obtuse. 

 Flowering scale narrow, awn persistent; callus 

 commonly acute. 



19. ZlZANIA. 



20. Homalocexchrus. 



21. Phalaris. 



22. anthoxanthum. 



23. Savastana. 



24. Milium. 



25. Oryzopsis. 



26. Stipa. 



