228 



compaPvAtitt: analysts. 



2. Flowers in unilateral spikes . . .3 

 FloAvers not unilateral ... 6 



3. Calyx many-flowered . . . Triticmn. 

 Calyx one or two- flow creel . . . 4 ' 



4. Styles united half way up . . . Spartina. 

 Styles distinct .... 5 



5. Grlumes nearly equal . . , Cijnoclon. 

 Glumes very unequal .... Bigitaria. 



6. Spikelets imbedded in the rachis . . Rottholia. 

 Spikelets not imbedded. ... 7 



7. Spikelets two or more from same point . .11 

 Spikelets solitary .... 8 



8. Spikelets one-flowered . . . Knappia. 

 Spikelets more than two-flowered . . 9 



9. Glume solitary, inclosing tlie spikclet between it and rachis LoUum. 

 Glumes two, their edges towards the rachis . .10 



10. Florets equal . . . Brachypodium. 

 Florets smaller upwards . . . Triticum. 



11. Spikelets one-flowered .... Hordeum. 

 Spikelets two or more flowered . . . Elymus. 



12. Calyx one-flowered . . . . 13 

 Calyx two or more flowered . . .23 



13. Glumes with feathery awns . . . Lagurus. 

 Glumes awnless, or awns not feathery . 14 



14. Panicle dense, (subspiked,) florets mostly imbricated . 15 

 Panicle loose, florets not imbricated . . 20 



15. Corolla with tuft of hair at base . . Amophilla. 

 Corolla without hairs at base . . . 16 



16. Corolla with one or two valves of imperfect florets at base Phalaris. 

 Corolla without valves of imperfect florets at base . 17 



17. Corolla awnless ..... Phleum. 

 Corolla awned . . . . 18 



18. Corolla of one valve, the awn basal . . Alopecurus. 

 Corolla of two valves, the awn terminal or dorsal . 19 



19. Glumes a-vvned, awn of corolla terminal . PoJgpogon. 

 Glumes awnless, awn of corolla dorsal . . Gastridium. 



20. Fruit inverted with the hardened corolla; corolla awnless 21 

 Fruit not inverted with the corolla; corolla often awned 22 



21. 



22. 



Corolla with a small valve at the base 

 Corolla without a valve at the base 

 Corolla with long hairs at base 

 Corolla without hairs at base 

 Florets with a pinnated bractea 



Phalaris. 

 Milium. 

 Calamagrostis. 

 Agrostis. 

 Cgnosarus. 



