XX SYNOPSIS OF GENERA. 



TRIBE VIII. Agrostidese.—Spikelets 1-flowered. Eachilla 

 jointed above the lower empty glumes, often produced beyond 

 the floret. Flowering glume with or without an awn. Pales 

 2-nerved, usually thin and transparent. 



Panicle lax. Spikelets cylindrical. Flowering glume 

 with a terminal 3-fid awn, rigid, and closely investing 

 the grain when mature. Slender feather-like grasses 

 with very narrow leaves.. 



Aeistida, p. 46. 

 Panicle spike-like, densely cylindrical or ovoid, stalked 

 or sessile within the upper sheaths. Flowering glume 

 blunt, loosely covering the grain. Habit of Crypsis. 

 {Vide Plate E., Fig. 23). 



Heleoohloa, p. 48. 



Spikelets in lax or in spike-like panicles, minute. 



Flowering glumes not awned. Grain usually exposed 



and falling readily from the glumes. Pericarp often 



quite loose. ( TTsar grass, &c.) ( Vide Plate E., Fig. 24). 



Sporoboltfs, p. 48. 

 Spikelets in a dense spike-like panicle. Outer empty 

 glumes narrow, keeled, and ending in a fine straight 

 awn. Flowering glumes shorter, with or without an 

 awn. Grain enclosed within the fruiting glume. (Vide 

 Plate E., Fig. 25). 



POLYPOGON, p. 50. 



TRIBE IX. Avenese. — Inflorescence loosely paniculate. Spike- 

 lets with two or more perfect florets. Eachilla produced be- 

 yond the upper floret. Flowering glume with a twisted or bent 

 awn, which is either dorsal, or terminal between two teeth. 



Florets hermaphrodite, or the upper one male. Awn 

 of flowering glume dorsal. Flowering glume rounded 

 on the back, many-nerved. Ripe grain furrowed in 

 front, more or less adhering to the pale. (Oats). 

 (Vide Plate E., Fig. 26). 



A VENA, p. 51. 



Spikelets in threes at the ends of the panicle branches, 

 2-flowered. Lower floret male, upper hermaphrodite 

 or female. Awn of flowering glume terminal between 

 the two lobes. 



Tristachya, p. 51. 



