GENERA OR FAMILIES. 181 



emarglnate, that of the male floret with a twisted awn at 

 the base, that of the hermaphrodite floret wdth a small 

 straight awn under the apex ; stamens three ; styles two. 



(319) Holcus — panicle somewhat open; lower floret hermaphro- 



dite, the upper male ; glumes two, nearly equal, boat- 

 shaped ; pales two, the outer of the male florets awned 

 under the apex, of the hermaphrodite floret awnless ; sta- 

 mens three ; styles two. 



ttt Spikelets one-flowered^ sessile along one side of the simple 

 linear hranches of the panicle (Chloridese). 



(320) Spartina — panicle of 2-4 erect, spike-like branches ; 



spikelets in two rows, pressed close to the rachis ; glumes 

 two, unequal ; pales two, nearly equal, both keeled ; 

 stamens three ; styles two. 



tttt Spikelets one- or several-floivered, sessile in the notches 

 of a simple spike (HordeineaB). 



X Spikelets one-flowered. 



(321) Leptnrus — spike slender, cylindrical; glumes two, hard, 



ribbed ; pales two, thin, awnless, about as long as the 

 glumes ; stamens three ; styles two. 



(322) Nardus — spike slender, simple, one sided ; glumes none ; 



pales two, the outer wrapping up the inner, which is flat ; 

 stamens three ; style one. 

 (823) Hordeum — spikes cylindrical, dense ; spikelets in threes, 

 1-2 usually neuter or barren ; fertile ones with one per- 

 fect floret and a rudimentary neuter one ; glumes two, 

 collateral, awned ; pales two ; stamens three ; styles two. 



XX Spikelets several flowered. 



(324) Elymus — spike cylindrical, rather dense ; spikelets in 

 ])air3, each containing 2-4 florets; glumes two, colla- 

 teral, awnless ; pales two, less pointed than the glumes; 

 stamens three ; styles two. 



