GRAMINE^. (GRASS FAMILY.) 841 



33. AGROSTIS. 2f Panicle loose. Glumes not aristate. 



34. POLYPOGON. Panicle spike-like. Gliimos anstate. 



1 1 Axis usually produced beyondfloweret into a glabrous or hairy bristle. 



3"). GASTEIDIUM. Glumes ventricose at base, not plumose. Spikes cylindrical. 



3G. AMMOPIIILA. 2^ Glumes membranous, firm. Panicle spike-likp. Tall sea- 

 side herbs. 



37. LAGUEUS. Glumes not ventricose at base, plumose. Heads ovate to ciblong. 



Tribe VII. AVENEiE, Spikelets 2-a> -flowered, the terminal floweret often tabes 

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

 or aristate at back, upper 2-nerved or keeled. 



* Spikclets 2-flowered, the axis not produced beyond flowerets. 



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



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

 t Lower pale with a long, dorsal awn, and bifid or ^-arcned at tip. 



39. ("UllYf^EPHOEUS. © Glumes muticous. Awn of lower pale club-8hai)od at tip. 



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



awned. Awn of lower pale hooked or bent. 



41. TEISETUM. If Spikelets small, panicles compact spike-like or l(»ose. Caryopsii 



not grooved, glabrous. 



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



Caryopsis grooved, glabrous. 



43. AVENA. If 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. AEEENATHEEUM. If Spikelets on capillary pedicels, panicle-s loose. Caryopsis 



teretish, pubescent. 



•(■ I Lower pale with a terminal awn betioeen tioo teeth, 



46. DANTHONIA. If Spikelets in a dense, spike-like panicle. Desert plaiit:<. 



Tribe VIII. CHLiORIDEiE. 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 sanguinalo. 



48. TETEAP060N. If Herbs,.with two, 2-ranked spikes, adhering by their inner far?, 



thus appearing 4-ranked. 



49 DACTYLOCTENIUM. Herbs with digitate spikes, much broader than those of 



Cynodon dactylum. 

 Tribe IX FESTU€EiE. Spikelets 2-a5-flowered, panicled or racemed, more or 

 less pedicelled. Glumes usually shorter than lower floweret. 



* Spikclets 5-6-flowercd. Lower pales oo -nerved, 7-9awned. 



50 PAPPOPHOEUM. • Lower pale with 9 awns excurrent from nerves. 

 51. BOISSIEEA. Lowerpale with 7-9 awns at base of hyaline tip. 



* * Spikelets 3-<X) -flowered. Lower pales 3-toothed or -cleft. 



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



53. DIPLACIINE. 2f Spikelets numerous, oo -flowered, panicle long, branched. 



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



long-hairy. 



54. AEUNDO. If Lower pale 2-cleft at tip, with an awn at sinus. All the flowerets 



except the uppermost fertile. Glumes equal . 



55. PlIEAGMITES. If Lower pale acuminate-aristate. Lower tloweret staminate or 



neuter. Glumes unequal. 



109 



