GRAMENEAE. 53 



T. Lower flower usually female ; flowering glume hardened 



as in Pa.nir.um ; panicle loose Isachne 12. 



K. Spikelets with 2 fertile flowers. 



U. Flowering glume with a short dorsal awn ; outor glumes 

 1-3-nerved ; panicle loose. 



Flowering glume acute or bifid Aira 40. 



Flowering glume truncate Deschampsia 41. 



U. Flowering glume awnless or with a short terminal awn ; 



outer glumes 9-11 -nerved Eriachne 39. 



U. Flowering glume with a long terminal awn and 2 lateral 



bristly lobes Pentascuistis 46. 



K. Spikelets with several fertile flowers. 



V. Flowers enveloped in long hairs ; panicle large Phragmites 52. 



V. Flowers not enveloped in long hairs. 



W. Flowering glumes entire, awnless or shortly awned. 

 X. Spikelets sessile in a terminal spike. 



Y. Spike compressed ; spikelets solitary in notches 

 of rhachis. 



Outer glume 1 Lolium 73. 



Outer glumes 2 Agropyrum 75. 



Y. Spike cylindrical ; spikelets in globular clusters Elytrophorus 49. 

 X. Spikelets shortly pedicellate in a terminal spike. .. . Brachypoditjm 67. 

 X. Spikelets sessile in several digitate or scattered 

 spikes. 



Spikelets crowded ; spikes digitate Dact yloctenium 7 1 . 



Spikelets more distant ; spikes scattered Leptochloa 72. 



X. Spikelets in a loose or contracted panicle. 

 Z. Flowering glume rounded on back. 



AA. Spikelets drooping and quivering Briza 57. 



AA. Spikelets erect ; flowering glume 5-nerved. 



Flowering glume acute, awnless, or with a 

 short terminal awn, the lateral nerves 



converging towards summit Festuca 65. 



Flowering glume obtuse, awnless, the lateral 



nerves almost parallel Glyceria 63. 



Z. Flowering glume keeled on back. 

 BB. Spikelets bisexual. 



CC. Spikelets in compact clusters ; flowering 



glume shortly awned Dactylis 58. 



CC. Spikelets not clustered. 

 DD. Ligule membranous. 



Flowering glume thin and usually 



woolly at base Poa 62. 



Flowering glume hard and glabrous at 



base Sclerochloa 64. 



DD. Ligule of hairs ; flowering glume 3- 



nerved, awnless Eragrostis 59. 



BB. Spikelets unisexual and dioecious, awnless.. Distichlis 60. 

 W. Flowering glume 3-lobed or notched, the midnerve 

 produced into an awn within the not^h. 

 EE. Spikelets of 2 kinds, the fertile surrounded by 



sterile ones Cynosurus 54. 



EE. Spikelets of 1 kind. 



FF. Spikelets forming a narrow panicle. 

 GG. Outer glumes shorter than the flowers. 

 HH. Flowering glume 3-nerved. 



Flowering glume with a straight awn 



half its length Koeleria 55. 



Flowering glume with 3 subequal teeth Triodia 50. 

 Flowering glume with 3 lobes tapering 



into long straight awns Triraphis 48. 



HH. Flowering glume 5-nerved, bifid, with a 



slender straight awn Trisetum 56. 



GG. Outer glumes as long as flowers ; flowering 

 glume 9 -nerved. 

 Flowering glume 2-lobed, with a twisted awn DanthOnia 45. 

 Flowering glume bifid and mucronate Schismus 61. 



