415 
10. Flowers, naked, with one stamen. 9—CixifA 
10. Flowers hairy, stamens three. 12 —Calamagrostis 
11. Stamens three..... 10 —Muiilenberqia 
11. Stamens two. 11 —Braciiyclytrum 
12. Glumes two. 13 
12. Glumes none, leaves retrorsely scabrous.1 —Leersta 
13. Pale® membranaceous. 14 
13. Pale® coriaceous.'48 —Milium' 
14. Fruit coated. 15 
14. Fruit naked.... 7 —Sporobolus 
15. Flowers stalked..,. 8 —Agrostib 
15. Floweis sessile. 6 —Vjlfa 
16. Flowers awned. 17 
16. Flowers without awns. 22 
17. Spikes solitary. 18 
17. Spikes numerous, not bearded, unilateral pale® cartilaginous. 50 —Panicum: 
17. Spikes two or more polygamous, sterile flowers, bearded . 55— Andropogon 
18. Spikes simple, or nearly so. 19 
18. Spikes paniculate, or lobed. 21 
19. Involuere none. 20 
19. Involuero of two or more bristles. 51— c etaria 
19. Involuere burr-like..... 52—Cenchrus 
20. Pale® with awns one to three times their length. 4 —Alopecurus 
20. Pale® with awns five times their length. 37—Hordeum 
21. Both glumes and paleae awned. 10—Mnhlenbergia 
21. Glumes awnless, paleae awned. 46—Anthoxanthum 
22. Flowers perfect or polygamous... 23 
22. Spikes monoecious. 25 
23. Spikes one-sided... 24 
23. Spikes cylindrical, solitary terminal. o—P hleum 
24. Spikes two or more, spikelets suborbicular. 49—Paspnlum 
24. Spikes digitate or verticillate, linear. 50—Panicum 
24. Spikes pedunculate, in a two-sided panicle. 16—Spartina 
24. Spikes sessile, in a one-sided panicle. 3—LepturuB 
25. Spikes all terminal, sterile above, fertile at base... 54—Tripsacuna 
25. Fertile spikes lateral, sterile ones terminal panicled.53—Zea 
26. Inflorescence in panicles. 27 
26. Inflorescence in spikes. 39 
27. Flowers awned. 28 
27. Flowers without awns. 33 
28. Lower palea awned on the back. 29 
28. Lower palea awned on the apex. 32 
29. Awn near the base of the palea. 30 
29. Awn near the apex of the palea. 31 
