GRAMINE^. (grass FAMILY.) 841 



33. AGROSTIS, 2(0 Panicle loose. Glumes not aristatn. 



34. POLYPOGON. 0. Panicle spike-like. Glumes anstate. 



t t jixis usually produced heyondfloweret into a glabrous or hairy bristle. 



35. GASTPtlDIUM. Glumes ventricose at base, not plumose. Spikes cylindrical. 



36. AMMOPHILA, 2f Glumes membranous, firm. Panicle spike-like. Tall sea- 



side herbs. 



37. LAGUPtUS. Glumes not ventricose at base, plumose. Heads ovate to oblong. 



Tribe VII. AVENEJE, Spikelets 2-a) -flowered, the terminal floweret often tabes- 

 cent, usually panicled. Glumes large, almost enclosing the spikelet. Lower pale muticou* 

 <»r aristate at back, upper 2-nerved or keeled. ^ ^"' 



* Spikelets 2-Jlowered, the axis not produced beyond flotoerets. 



38. AIIJA. Pedicels capillary, panicled. Awn not jointed or club-shaped. 



* * Spikelets 2-flowered, the axis more or less produced beyond flowerets . 

 t Lower pale with a long, dorsal awn, and bifid or2-aioned at tip. 



39. CORYNEPHOEUS. © Glumes muticous. Awn of lower pale club-shaped at tip. 



40. IIOLCUS. If Glumes of perfect floweret muticous, of staminate nmcronulate or 



awned. Awn of lower pale hooked or bent. 



41. TRISETUM. If Spikelets small, panicles compact spike-like or loose. Caryopsis 



not grooved, glabrous, 

 49. VENTENATA. Spikelets medium, on club-shaped pedicels (ours) in a loose panicle 

 Caryopsis grooved, glabrous. 



43. AVENA. 21 Spikelets large, on capillary or thickened pedicels, panicle loose, or 



compact spike-like. Caryopsis grooved, hairy. 



44. GAUDINIA. Spikelets 2-ranked in excavations of axis, forming a, linear spike. 



Caryopsis grooved, ciliate at tip. 



45. ARRENATIIERUM. If Spikelets on capillary pedicels, panicles loose. Caryopsis 



teretish, pubescent. 



1 1 Lower pale with a terminal awn between two teeth, 

 40. DANTHONIA. 2f Spikelets in a dense, spike-like panicle. Desert plants. 



TiuBE VIII. CIIIiORIDEiE. Spikelets l-oo -flowered, perfect, sessile, 2-ranked 

 along the axis of 1-sided spikes, ' 



47. CYNODON. If Weeds with digitate spikes; aspect of Panicum sanguinale. 



48. TETRAPOGON. 21 Herbs, witli two, 2-ranked spikes, adhering by their inner lace 



thus appearing 4-ranked. 



49. DACTYLOCTENITJM. Herbs with digitate spikes, much broader tlian those of 



Cynodon dactylum. 



Tribe IX. FESTITCEJE, Spikelets 2-qo -flowered, panicled or racemed more or 

 less pedicelled. Glumes usually shorter than lower floweret. ' 



* Spikelets 5-6-flowered. Lower pales ao -nerved, 7-9-awned. 



50. PAPPOPHORUM. Lower pale with 9 awns excurrent from nerves. 



51. BOISSIERA. Lower pale with 7-9 awns at base of hyaline tip. 



* * Spikelets 3-co 'flowered. Lower pales 3-toothed or -cleft. 



52. TRIODIA. If Spikelets 1-3 in an interrupted spike, 3-5-flowered, included in glumes. 



53. DIPLACHNE, 2f Spikelets numerous, oo -flowered, panicle long, branched.^ ' •' ' • 

 * * * Spikelets 2-co -flowered, the axis under lower pales, and often the pales themselves 



long-hairy. ..•«*');i.i >-; V, 



54. ARUNDO. 2f Lower pale 2-cleft at tip, with an awn at sinus. Jkll«the flowerets 



except the uppermost fertile. Glumes equal. ,i]r .r-:) i/< .:i.[ .,- 



55. PHRAGMITES. 2f Lower pale acuminate-aristate. Lower. i^q(\V,q»e1j /BUmiiale ot 



neuter. Glumes unequal. :. ,!, ,,m.'..„ .u: 



109 



