COMPARATIVE ANALYSIS. 231 



PoLYPOGON. 



Awns as long as the calyx, root creeping . . Littoralis. 



Awns much longer than the calyx, root fibrous . Monspeliensis. 



Calamagrostis. 



1. Corolla with a terminal awn, panicle loose . Lanceolata. 

 Carolla with a dorsal or basal awn, panicle close . 2 



2. Flowers without a rudiment of a second floret . Epigejos. 

 Flower with a minute pedicel, bearing a tuft of hair 



(a rudiment of a second floret) . . .3 



3. Hairs as long as the corolla, awn near the base . Lapponica. 

 Hairs shorter than the corolla, awn above the middle . Stricta. 



Ageostis. 



1. Inner valve of corolla wanting, or minute . 2 

 Inner valve of corolla not minute . . .3 



2. Leaves linear, awn dorsal . . . Canina. 

 Leaves setaceous, awn basal . . . Setacea. 



3. Awn very long and terminal, florets with a barren pedicel 



at base .... Spica-venti. 



Awn none, or short and dorsal, no barren pedicel . 4 



4. Ligule short and truncate, outer valve of corolla three-nerved Vulgaris. 

 Ligule oblong, outer valve of corolla five-nerved . Alba. 



Catabeosa. 

 Branches whorled .... Aquatka. 



Ateochloa. 

 Glumes shorter than the florets . . . Cristata. 



Aiea. 



1. Awn clavate .... Canescens. 

 Awn not clavate .... 2 



2. Leaves linear, awns not or but little longer than corolla 3 

 Leaves setaceous, awns longer than corolla . 4 



3. Awn basal, branches rough . . Ccespitosa. 

 Awn dorsal, branches smooth . . . Alpina. 



4. Florets hairy at base .... Flexuosa. 

 Florets scarcely hairy at base ... 5 



5. Panicle close, awn basal .... Precox. 

 Panicle spreading, awn dorsal . . . Caryophjllea. 



Melica. 



1. Panicle drooping, florets not longer than the calyx . 2 

 Panicle erect, florets much longer than the calyx . 3 



2. Spikelets with two perfect florets . . . Nutans. 



