TnK Grasses ok Tennessee. 113 



56. Flowering flumes compressed, keeled, usually beariuj^ a tuft 

 of coi)webby hairs at the base, and sometimes soft hairs on 

 the more prominent nerves below. (wSee Fig. 60.) 53. Poa. 



56. Flowering glumes rounded on the back, naked or pubes- 



cent, not cobwebby at base (spikelets much flattened and 

 glumes compressed in Bromus unioloides.) 57 



57 Styles inserted below the apex of the ovary, which lias a 

 hairy, cushion like summit. (See Fig. 31.) .56. Bromus. 



57. Styles terminal; grain smooth 58 



58. Flowering glumes awnless, nerves prominent . .54. Glyceria. 



58. Flowering glumes often awned, nerves indistinct (visible 



only near the apex) 55. Festuca. 



59. Spikelets single at each joint of the rachis 60 



59. wSpikelets two or more at each joint of the rachis 63 



60. Spikelets placed edgewise to the rachis; empty glume (except 



in the terminal spikelet) one. (vSee Fig. 29.) 57. Lolium. 



60. Spikelets placed with their sides against the rachis, empty 



glumes two . . 61 



61. Flowering glumes with a distinct callus, falling at maturity 



with the grain, which is adherent to the palea. (See 

 Fig. 67.) 58. Agropyrum. 



61. Flowering glumes without a distinct callus, persistent; 



grain free 62 



62. Empty glumes subulate, one-nerved . . . 59. Secale. 



62. Empty glumes lanceolate or ovate, three to many-nerved 



60. Triticum. 



63. Spikelets with only one hermaphrodite flower. 61. Hordeum. 



63. Spikelets with two or more hermaphrodite flowers 64 



64. Empty glumes nearly equalling the flowering glumes 



62. Elymus. 



64. Empty glumes, minute or none 63. Asprella. 



_ Figures 29, 30, 31, 32, 33, 35, 36, 37, 38, 39, 41, 42, 43, 45, 47, 48, 51, 53, 54, 55, 

 56, 57, 59, 60, 67, 6S, 70, 71 and 72 are from electrotpyes which were obtained by 

 purchase from Wilhelm Engelmann, of Leipzig, publishers of "Die Naturlichen 

 Pflanzenfamilien." 



