GRAMINEAE (GRASS FAMILY) 



41 



Tribe VIII. CHLORIDEAE 



Spikelets with perfect flowers. 



Spikelets deciduous as a whole, the articulation below the glumes. 



Spikelets much flattened; glumes unequal, keeled . . .40. Beckmannia. 

 Spikelets subterete; glumes equal, convex .... 37. Spartina. 

 Spikelets in part persistent, the articulation above some of the 

 glumes. 



Spikes few (1-4) . . . 38. Bouteloua. 



Spikes numerous. 



Spikes long, very slender; plant annual . . . .34. Schedonnardus. 



Spikes short, one-sided . . . . . . . 39. Atheropogon, 



Spikelets with imperfect flowers, the pistillate very different from the 



staminate and on very short culms ..... 41. Buchloe. 



Tribe IX. FESTUCACEAE 



Lemma 3-lobed and 3-awned 42. Scleropogon. 



Lemma entire or 2-lobed. 



Rachilla long-hirsute ..'....... 44. Phragmites. 



Rachilla glabrous or with short hairs. 



Plant prostrate, with spinescent leaves ..... 43. Munroa. 



Plants, erect, leaves not spinescent. 

 Lemma 3-nerved (or rarely 1). 

 Lateral nerves hairy. 



Inflorescence a congested raceme; leaves with cartilagi- 

 nous margins . . . . . . . .45. Tricuspis. 



Inflorescence a panicle; leaves not cartilaginous on the 



margins ........ 47. Diplachne. 



Lateral nerves glabrous. 



Lemma long-hirsute at base . . . . . .46. Redfieldia. 



-Lemma glabrous at base. 

 Glumes similar. 



Inflorescence spike-like ...... 50. Koeleria. 



Inflorescence an open panicle. 



Rachilla continuous; flowering glumes decidu- 

 ous, the palet persistent . . . .48. Eragrostis. 



Rachilla articulated; flowering glume and palet 



both deciduous ...... 51. Catabrosa. 



Glumes very dissimilar ...... 49. Eatonia. 



Lemma 5-nerved or more. 



Spikelets with the upper florets sterile and folded about 



each other 52. Melica. 



Spikelets with the upper floret perfect, or narrow and 



abortive 



Stigmas arising below the apex of the^ ovary . . . 60. Bromus. 

 Stigmas arising at the apex of the ovary. 

 Lemma compressed and keeled. 



Awn-pointed 54. Dactylis. 



Pointless. 



Glumes 1 -3-nerved. 



S carious-margined . . . . .55. Poa. 



Membranous ....... 56. Graphephorum. 



Glumes 5-nerved or more ..... 53. Distichlis. 



Lemma convex or rounded on the back. 



Acute or awned 59. Festuca. 



Obtuse and scarious at apex. 



Prominently 5-7-nerved ..... 67. Glyceria. 

 Obscurely 5-nerved ...... 58. Puccinellia. 



Tribe X. HORDEAE 

 Spikelets mostly solitary at each joint of the rachis. 



Spikelets placed edgewise on the rachis 61. Lolium 



