-■57. (;R AMINE Jv 



157 



Involucre of stiff persistant bristles: 

 spikelets oblong; glumes as in 



Pan if urn 



Involucre of flexible, deciduous, 

 plumose bristles; spikelets cylin- 

 drical 



D. Spikelets without a bristly involucre ; 

 outer glumes longer than the flower. 

 E. Spikelets awned. 



F. Flf>wering- glume awned ; outer 



glumes equal. 



Outer glumes 1-ncrved, long- 



awned, much exceeding the 



flower. 



Flov/ering glume with 1 short 



awn; spike oblong, bristly ... 



Flowering glume with 3 awns ; 



spike ovoid, plumose 



Outer glumes 3-nerved, not 



awned; no palea 



F. Flowering glume awnless. 



Outer glumes equal, shortly 



awned; stamens 3. 



(Hiter glumes unequal, awnless ; 

 2 awned empty glumes at 

 base of flowering glume ; 



stamens 2 



E. Spikelets without awns. 



Outer glumes with a winged keel ; 



aruiual and perennial grasses 



Outer glumes sim.ply keeled ; 



perennial sand-binding grass 



B. Spikelets arranged in a loose panicle. 



G. Spikelets in 2's or 3"s. one sessile and 



fertile, the other, 



stalked and barren 



G. Spikelets solitary or 



stalked and alike. 



H. Spikelet containing 



flower. 



Outer glumes 2, longer 



flower ; stamens 3. 



Outer glumes convex on the back 



Outer glumes compressed and 



keeled 



Outer 



or 



2 others, 

 clustered, all 

 only 1 fertile 

 than the 



3, the lowest small 

 (partly) 



4, the 2 outermost 

 persistant ; stamens 



ning 1 fertile flower 

 flower. 



male, longawned ; 

 upper fertile; almost glabrous 



grass 



Lower flower fertile, awnless ; 

 upper male: softly hairy grass 



lumes 



Outer glumes 



small and 



4-6 ... . 



H. Spikelet conta 



and 1 male 



Lower flower 



Set.\eia 6 



PENNISETrM 7 



PoLYPonox 8 



L.^GURI'S 9 • 

 ALOPECTErS 10 



Phlefm 



Anthox-^nthtm 11 



Phai,ai;is 12 

 Ammophil.v 13 



Sorghum 14 



Oeyzopsis 15 

 Agp.ostis 16 

 Panictm 1 



Ehrhap.ta 17 





Arkhen.\theeum 18 

 HoLcus 19 



