LXXXIX. 



505 



of food for man, in the shape of grain, and for cattle As constituting the 

 chief portion of meadows and pastures. 



, f Spikelete 1-flowered .... 2 



1 Spikelets containing 2 or more flowers . .24 



f Spikelets arranged along one side of a slender, simple, linear spike . . 8 



9 f Spikelets arranged along one side of the simple, linear branches of the panicle 5 

 J Spikelets arranged in a close, cylindrical or ovate spike or spike-like panicle . 7 



^Spikelets arranged in a loose, branching panicle 16 



Spikelets 1-flowered, in one-sided linear spikes. 

 f Glume 1 only, ending in a fine point, and enclosing the palea and flower, 



NARDUS. 



. 4 

 10. MlBORA. 



Axis jointed. 



23. LEPTURTJS. 

 3. PANICUM. 



( Two outer .empty glumes and a flowering one 

 ( Outer glumes 1 line long, thin, and obtuse. Axis not jointed . 

 4 1 Outer glumes 2 lines long, stiff, and strongly ribbed. ' 



, /Spikelete in pairs or clusters along the branches 



\ Spikelete single along the branches 



( Spikelete half an inch long, laterally flattened. Glumes all strongly keeled, 



6-^ erect 22. SPARTINA. 



( Spikelete about a line long. Outer glumes spreading . . 21. CYNODON. 



Spikelets 1-flowered, in a dense spike or spike-like panicle. 

 7 f Outer glumes without awns. Flowering glumes with or without awns . . 8 



\ All the glumes awned 13 



f Only 2 nearly equal empty glumes enclosing the flower 9 



S J An additional small empty glume outside the 2 equal ones . 3. PANIOUM. 

 | Two additional small, awned, empty glumes, withinside the two equal ones. 



6. ANTHOXANTHUM. 



( Outer glumes swollen and shining at the base. Spikelete rather small. 

 9^ 14. GASTRIDIUM. 



( Outer glumes keeled or boat-shaped 10 



( A tuft of hairs at the base of the flower, within the outer glume. Reed-like 



10 \ grass with a very long spike 15. PSAMMA. 



( No tuft of hairs outside the flower within the outer glumes. Spikelets flat . 11 

 Flowering glume with a fine awn on its back (sometimes shorter than the 



outer glume). No inner palea 9. ALOPECURUS. 



Flowering glumes without awns. Inner palea present 12 



Keel of the outer glumes expanded into a flat wing ... 6. PHALARIS. 



Keel of the outer glumes not winged 8. PHLEUM. 



Spikelete 3 together on each tooth of the simple, close, cylindrical spikes, 



1 or 2 of each cluster reduced to a pair of empty glumes . . 26. HORDEUM. 

 Spikelete small and numerous, in a close spike-like panicle, all containing 



flowers 14 



Flowering glumes without awns 8. PHLEUM. 



Flowering glumes awned as well as the outer ones 15 



Spike ovate, with long softly silky hairs . . . . . 11. LAGURUS. 

 Spike cylindrical or branched, not hairy ... .12. POLYPOGON. 



Spikelets l-flowered t in a loose panicle. 



Spikeleto ovate, obtuse or scarcely acute 17 



Spikelete lanceolate, pointed 19 



Spikelete very flat, consisting of only 2 glumes, both keeled . . 1. LEERSIA. 

 Spikelets scarcely flattened. Two outer empty glumes about the size of the 



flowering one 18 



Spikelete rather large, containing within the outer glumes, besides the flower, 



a small, wedge-shaped, terminal glume or rudimentary flower 38. MELICA. 

 Spikelete small, containing nothing besides the flower within the outer 



glumes 2. MlLlUM. 



( Small tufts of hairs or hairy appendages at the base of the flower within the 



v outer glumes 20 



( No hairs or hairy appendage at the "base of the flower within the outer glumes 21 

 'No awns. A small hairy appendage at the base of the flower on each aide. 



7. DIGRAPHIS. 

 Flowering glume with a short fine awn. A tuft of hairs at the base of the 



flowers ... 16. CALAMAOROSTIS. 



11 



12 



13 



16 



17 



IS 



19 



