POACEAE. 



Tribe 5. FESTUCEAE. 



erved, rarely l-msrved. 50. Sphenopholis, 30. 

 Glumes obtuse, very unlike. 



Glumes acute, subequal. ky.fi fria 30 



Panicle close; spikclets 2-4-flowered. 51. Koeleria, 5U. 



U. looser; spikclets usually man >'- 52 Eragrostis , 30 . 

 flowered. 

 nil. 1 5-nerved or more. , 



Spikelets with the upper florets stenle and 



ToWed about each other. 53. melica, ai. 



Spikelets with the upper florets perfect, or 



narrow and abortive. n. n . nTS 39 



mas arising below the apex of the ovary. 54. Bromus, 51. 



9 arising at the apex of the ovary. 

 L.mmas compressed and keeled. n . rT ,_ IS « 



Lemma awn-pointed. 55. DACTYLIS, 55. 



I.. -inuias pointless. 56. f OA, 55. 



Lemmas convex or rounded on the back. 



Lemmas acute or awned. »/• * estuca, 00. 



mmas obtuse and scarious at apex. 58. Panicularia, 51. 



Tribe 6. CHLORIDEAE. 



Spiktkts much flattened; glumes unequal, keeled. 59. Spartina, 38. 



Spikelets subterete; glumes equal, convex. 60. Beckmannia, 38. 



Tribe 7. HORDEAE. 



Spikelets solitary at the notches of the rachis; glumes 



usually acute, or awned. 61. Agropyron, 39. 



Spikelets 2-6 at each notch of the rachis; glumes mostly 

 long-awned. 

 Rachis not readily breaking into joints; spikelets 



lowered, 2-4 at each joint. 62. Elymus, 40. 



Rachis readily breaking into joints. 



Spikelets 1 -flowered, 3 at each joint, only the 



. <ntr.il one perfect. 63. Hordeum, 41. 



Spikelets l-5-flowered, 2-4 at each joint, all 



perfect. 64. Sitanion, 42. 



30. ECHINOCHLOA. 



annuals with long leaves; spikelets 1-flowered, with 

 unetimes a -laminate flower below, nearly sessile in 1-sided 

 spikes or racemes; glumes unequal, hispid, mucronate; sterile 

 lemma similar and usually awned from the apex. 



Echinochloa crus-galli (L.) Beauv. Barnyard Grass. Glabrous; stems 



it, branching at the base, 30-120 cm. tall; panicle dense, 10-20 cm. long, 



1 <1 ..f many ascending or spreading racemes; spikelets green or purple, 



mm. long, densely crowded in 3 or 4 rows; sterile lemma awned or in some 



Introduced from Europe, a weed in moist ground. 



31. CHAETOCHLOA. 



Annual gi with eivrt stems and flat leaves; spikelets with 



<>ne perfeel flower and rarely also a staminate one, in spike-like 



