ORDER CXLII. GRAMINACE^. 571 



19. Inferior flower neutral 20 



Baperior flower neutral 



20. Flowers with a h dr-like involucre Erianthus, 42 



Pales of the fertile flowers coriaceous 21 



Pales membranaceous Andropogon, 43 



21. Paleae awned Oplismenut, 12 



Pales not awned Panicum, 10 



22. Spikes by fours, digitate ChloHs, 20 



Spikes terminal, simple Iiottbcellia. 11 



23. Spikes terminal, simple Cenchrus, 14 



Spikes terminal, compound Setaria, 13 



24. Flowers monoecious 25 



Flowers not monoecious 26 



25. Staminate and pistillate flowers on the same spike Tripsacum, 39 



Staminate and pistillate flowers not on the same spike Zea, 4 



26. Inflorescence paniculate 27 



Inflorescence spicate 40 



27. Lower palea awned 23 



Lower palea not awned 34 



2S. Awn at the apex of the palea 29 



Awn at the back of the palea 31 



29. Pa'ese entire Festuca, 32 



Paleae toothed or divided 30 



30. Awn twisted at the base Danthonia, 26 



Awn straight Uralepis, 27 



31. A wn near the base of the palea 32 



Awn near the apex of the palea Bromus, 33 



32. Pa ] ea entire, emarginate Anthoxanthum, 8 



Talea bicuspidate 33 



33. Spikelets 2-flowered Aira, 25 



Spikeiets more than 2-flowered Arena, 26 



34. Lower paleae entire 35 



Lower paleae toothed Aira, 25 



35. Spikelets 2— 3-flowered 36 



ete usually more than 3-flowered 37 



36. Pales 4 Phalaris, 7 



Pales 2 Melica, 29 



37. Spikelets flat, ancipital Uniola, 34 



Spikelets cordate Briza, 30 



Spikelets ovate 33 



3S. Paleae herbaceous 39 



Paleae membranaceous Poa, 23 



89. Lower palea many-nerved Arundinaria, 35 



Lower palea few-nerved Festuca, 32 



40. Spikes paniculate 41 



Spikes digitate Eleusine, 21 



Spikes single 42 



41. Spikes short DactylU, 31 



Spikes Ion -z Eleu&ine, 21 



42. Glumes wanting Elymus, 37 



Glumes present" 43 



43. Paleae awned below the summit Monoccra, 22 



Paleae not awned below the summit Elymus, 37 



Tribe L— ORY'ZE^E. 



Spikelets 1-flowered. Flowers often monoecious, in branched 

 panicles. 



