48 GRAMINACEAE (GRASS FAMILY) 



LOLIUM (Rye Grass) 



Leaves flat. Spikelets in a simple terminal spike, several-flowered, 

 sessile alternate; rachis somewhat zigzag; rachilla jointed between the 

 flowers. Glume i except in the terminal spikelet, opposite the rachis. 

 Lemma rounded on the back, 5-7-veined, obtuse to awned. Palet 2-keeled. 

 Stamens 3. Grain smooth, adherent. — (Latin name.) 



A. Perenuial; glumes shorter than the spikelet (less the awns); ieaf sheaths shorter 

 than the internodes. W. — An early range grass. 



L. perenne (perennial rye grass) 

 AA. Annual; glumes equaling or exceeding the spikelets (less the awns); leaf sheaths 

 longer than the internodes. W. — Seed slightly poisonous to man. 



L. temulentum (darnel) 



AGROPYRON (Bunch-grass) 



Perennial ; stem erect, simple. Spikelets in a spike, closely sessile. 

 Glimies narrower than the lemjna, acute or awned. Lemma rounded on 

 the back or slightly keeled above. 5-7-veined, obtuse to awned at apex. 

 Palet 2-keeled, bristly ciliate on the keels. Grain pubescent at apex. — 

 Range grasses. (Gk. agros = field, pyros = wheat ; they were weeds in 

 wheat.) 



A. Plants densely tufted; lemma not hairy. 

 B. Glume awns 1-2.5 cm. long; glumes 4-6 mm. long. 



C. Herbage pubescent; spike dense. E. A. saxicola 

 CC. Herbage glabrous; spike loose. E. A. flezuosum 



BB. Glume awns either none or more than i cm. long. 



D. Some of the lemma awns longer than their lemmas. 



E. Glumes exceeding the lower lemma (less the awns); lemma awns erect, not 

 at all divergent. E. A. richardsoni 



EE. Glumes shorter than the lower lemma (less the awns) ; lemma awns diver- 

 gent or widely spreading. 

 F. Glumes attenuate into a scabrous awn. 

 G. Spikes 4-7 cm. long; rachis readily breaking at joints; glumes 5-8 mm. 

 long (less the awn). C. E. A. scribneri 



GG. Spikes 10-25 cm. long; rachis not readily breaking at joints; glumes 

 10-14 mm. long (less the awn), E. A. gmelini 



FF. Glumes awnless. E, A. spicatum (wheat bunch-grass) 



DD. Lemma awns shorter than their lemmas or none. 

 H. Spikelets flattened. (See FF.) 

 HH. Spikelets terete or nearly so. 

 I. Lower glume 3-veined. 

 J. Leaves 3.5-9 cm. long; glumes scabrous on the keel. E. A. brevifolium 

 JJ. Leaves 7.5-20 cm. long; g'lumes scabrous on the margin. E. A. biblorum 

 n. Lower glume s-veinea. 

 K. Spikes 3-10 cm. long; glumes mostly widest above their middle. E, 



A. Tiolaceum 

 EK. Spikes 8-20 cm. long; glumes mostly widest below their middle. E. 



A. tenerum 

 AA. Plants not tufted, stems from creeping rootstocks. 



