45- sph/erocaryum. 



46. polypogon. 



47. sporobolus. 



48. Calamagrostis. 



Graminecz. 119 



Exceptions. — Spikelets articulate at the base and deciduous in Gar- 

 notia, Sphcerocaryum, Polypogon, some Sporodoti, and Lophatherum. 

 Lower fig. glumes neuter or male in Phragmites and Pommereulla. 



A. Perennial, or annual herbs (never shrubby or arboreous). 

 1. Spikelets not inserted in notches or pits of a simple rhachis, except 

 in Oropetium, 



Tribe VIII. Stipeae. — Spikelets panicled, i-fld., rhachilla not produced 

 beyond glume III, which is bisexual, awned, hardened in fr., and 

 tightly envelops the grain. 

 Awn 3-fid 43. Aristida. 



Tribe IX. Agrostideae. — Spikelets panicled, i-fld., rhachilla some- 

 times produced beyond the upper glume ; glumes 3, membranous, 

 I and II 1-3-veined, usually longer than the flg. ; stam. 2-3. 

 Spikelets terete, glumes all 3-veined . . -44- Garnotia. 

 Spikelets ellipsoid, glumes II and III 1 -veined, 

 Spikelets laterally compressed. 

 Glumes I and II awned 

 Glumes I and II not awned, membranous. 

 Pericarp of grain loose 

 Pericarp of grain adherent to the seed, 

 hairs of callus very long . 



Tribe X. Aveneae. — Spikelets panicled, 2- or more-fid. ; glumes 4 or 



more, I and 1 1 usually hyaline or scarious, flg. with a usually twisted 



awn ; stam. 2-3. 

 Subtribe 1. EUAVENE^E.— Spikelets 2-many-fld., rhachilla produced 



beyond the uppermost flg. glume . . .49. Avena. 

 Subtribe 2. AIREvE. — Spikelets panicled, 2-fld., glumes 4, membranous 



or chartaceous, rhachilla not produced beyond glume IV. 



Spikelets awned 50. Eriachne. 



Spikelets not awned. 



Rhachilla short 51. Zenkeria. 



Rhachilla elongate between glumes III and IV 52. Ccelachne. 



Tribe XI. Chlorideae. — Spikelets small or minute, sessile or subsessile, 

 secund and 2-seriate in very slender solitary digitate racemed or 

 panicled dense-fld. spikes, rarely 3-many-seriate or alt. and distant, 

 1- or more-fld., empty glumes 1 -veined, flg. 3-veined — the infl. of 

 Gracilea is abnormal. See Lepturus in Tribe HordeacecB. 

 Spikelets i-fld., half sunk in the alt. cavities of 



a solitary simple spike . . . .53. OROPETIUM. 

 Spikelets 2-seriate, crowded in a solitary ter- 

 minal spike. 



Spikelets 1-2-fld 54. Enteropogon. 



Spikelets 3-many-fld 55. Tripogon. 



Spikelets 2- rarely many-seriate, crowded in 

 digitate racemed or panicled spikes (spike 

 rarely solitary in Chloris). 

 Spikelets i-fld. (see also Leptochloa). 



Glumes 3, III not awned . . . .56. CYNODON. 

 Glumes 4-8, III awned . . . .57. Chloris. 

 Spikelets 2- or more-fld. 



Spikes digitate or whorled, not awned . 58. Eleusine. 

 Spikes racemed, glumes I and II awned . 59. Dinebra. 



