Jones: Flora of Illinois, 22. Gramineae 49 



12. Lemma 1-awned. 



13. Awn twisted or bent 42. Stipa 



13. Awn not twisted or bent. 



14. Lemma broad, the awn deciduous 41. Orpzopsis 



14. Lemma narrow, the tip awned or mucronate. 



15. Rachilla not prolonged behind the palet 36. Muhlenbergia 



15. Rachilla prolonged into a bristle behind the palet.. .. 39. Brac/il;e/p(rum 



Tribe 6. Chlorideae. — Grama Tribe 

 l.Spikelets with more than 1 perfect floret; plants annual. 



2. Spikes numerous, slender, racemose 47. Leptochloa 



2. Spikes few, digitate. 



3. Rachilla prolonged beyond the spikelets 45. Daciyloctenium 



3. Rachilla not prolonged 44. Eleusine 



l.Spikelets with only one perfect floret. 



4. Spikelets with one or more modified florets above the perfect one. 



5. Spikes digitate 5 1 . Chloris 



5. Spikes racemose 52. Bouteloua 



4. Spikelets without additional modified florets. 



6. Spikelets falling entire, the rachilla articulated below the glumes. 



7. Spikelets narrow; glumes unequal 50. Sparlina 



7. Spikelets globose; glumes equal 49. Becl(mannia 



6. Spikelets with the rachilla articulated above the glumes, these therefore persistent. 



8. Spikes digitate 46. C'^nodon 



8. Spikes racemose 48. Schedonnardus 



Tribe 7. Phalarideae. — Canary Grass Tribe 



1. First and second lemmas oval. 



2. Glumes nearly equal; lower florets staminate; spikelets brown, o\ossy. . 53. Hierochloe 

 2. Glumes very unequal; lower florets consisting of sterile lemmas.. ..54. Anthoxanthum 



1. First and second lemmas bristle-like 55. Phalaris 



Tribe 8. Oryzeae. — Rice Tribe 



l.Spikelets perfect; stamens 1-3 56. Leersia 



l.Spikelets unisexual; stamens 6 57. Zizania 



Tribe 9. Paniceae. — Millet Tribe 



l.Spikelets with an involucre of bristles or spine-bearing valves. 

 2. Spikelets subtended by bristles; inflorescence a dense, spike-like panicle.. ..63. Selaria 



2. Spikelets in a spiny involucre 64. Cenchrus 



L Spikelets not involucrate. 



3. Glumes awned or awn-pointed 62. Echinochloa 



3. Glumes not awned. 



4. Glumes 2 60. Paspalum 



4. Glumes 3. 



5. Spikelets in slender, I -sided racemes 58. Digiiaria 



5. Spikelets in panicles. 



6. Margins of lemma hyaline, flat; ligule a scale 59. Lepioloma 



6. Margins of lemma not hyaline, more or less inrolled; ligule of hairs 



6 1 . Panicum 



