LXXXIX. GRAMINE^3. 505 



of food for man, in the shape of grain, and for cattle as constituting 1 he 

 chief portion of meadows and pastures. 



, /Spikelets 1-flowered .... 2 



\ Spikelets containing 2 or more flowers 24 



f Spikelets arrange*! along one side of a slender, simple, linear spike . . 3 



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

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

 V. Spikelets arranged in a loose, branching panicle 16 



Spikelett l-flowered, in one-sided linear spikes. 



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

 3^ 24. NARDUS. 



( Two outer empty glumes and a flowering one 4 



( Outer glumes 1 line long, thin, and obtuse. Axis not jointed . 10. MIBORA. 

 4-j Outer glumes 2 lines long, stiff, and strongly ribbed. Axis jointed. 



( 23. LEPTURUS. 



,( Spikelets in pairs or clusters along the branches . . . 3. PANICUM. 



\Spikelets single along the branches 6 



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



erect 22. SPARTINA. 



Spikelets about a line long. Outer glumes spreading . . 21. CYNODON. 



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

 t. 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. PANICUM. 

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



5. ANTHOXANTHUM. 



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

 9-} 14. GASTRIDITJM. 



( 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. ALOPECURTTS. 



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. 



Spikelets 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. 

 Spikelets 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 



11. LAGURUS. 



15 



Spike ovate, with long softly silky hairs 

 Spike cylindrical or branched, not hairy 



. 12. POLTPOGON. 

 Spikelets l-flowered, in a loose panicle. 



. ,,/ Spikelets ovate, obtuse or scarcely acute 17 



10 \Spikelets lanceolate, pointed 19 



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



17 4 Spikelets scarcely flattened. Two outer empty glumes about the size of the 



( flowering one 18 



f Spikelets rather large, containing within the outer glumes, besides the flower, 

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



18 j Spikelets small, containing nothing besides the flower within the outer 



^ glumes 2. MlLICM. 



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



19 ! outer glumes 20 



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



4 No awns. A small hairy appendage at the base of the flower on each side. 

 7. DIGRAPHIS. 

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

 flowers 16. CALAMAGROSTK. 



