GRAMINACEAE (GRASS FAMILY) 49 



L. Lemma hairy. 

 M. Lemma villous; spike rather dense. 

 N. Spikelets s-y-flowered. E. A. subvUlosum 



NN. Spikelets 7-13-flowered. E. (See PP.) 

 MM. Lemma puberulent; spike long and not dense. E. A. lanceolatum 



LL. Lemma not hairy. 

 O. Leaves smooth beneath, pubescent above. W. E. — Rhizomes medicinal. A 

 bad weed in cultivated fields. A. repens (couch grass) 



00. Leaves rough on both sides. 

 P. Spikelets 4-7-flowered. (See KK.) 

 PP. Spikelets 7-13-flowered. W. E. A. occldentalls (bluejoint) 



HORDEUM (Barley) 



Leaves flat. Spikelets in spikes, 2-3 together at a joint of the rachis, 

 sessile or short-stalked, often only i fertile in a cluster, i-flowered, awned, 

 lateral ones usually imperfect and short stalked. Glumes setaceous to 

 narrowly lanceolate, rigid, persistent. Lemma lanceolate, rounded on the 

 back, obscurely s-veined above, usually awned. Palet shorter than the 

 lemma, 2-keeled. Stamens 3. Grain hairy at tip, grooved, adherent. — 

 (Latin name for barley.) , 



A. Only the central spikelet of each group fertile. 



B. Flower of the central spikelet plainly stalked; glumes ciliate. W. E, — The 

 barbed seeds get into the wool of sheep and into the eyes and throats of animals, 

 sometimes even killing them. H. murlnum (wall barley) 



BB. Flower of the central spikelet sessile; glumes not ciliate. 

 C. Heads exclusive of awns about 5 mm. wide. 

 D. Lemma awn of central spikelet 3.5-6 cm. long, of the lateral spikelets over 

 half the lemma. W. E. — The beards collect in the mouths of cattle, caus- 

 ing ulcers and even death. H. jubatum (squirrel-tail grass) 

 DD. Lemma awn of the central spikelet 1.8-3 cm. long, of the lateral spikelets 

 over half the lemma. 

 E. Blades and sheaths of leaves glabrous. W. E. H. caespitosum 

 EE. Blades and sheaths of leaves pilose' E. H. comosum 

 DOD. Lemma awn of the central spikelet o.4-r.2 cm. long, of the lateral spikelets 

 not over half the lemma. 

 F. Lateral spikelets with perfect flowers. E. H. boreale 

 FF. Lateral spikelets with imperfect flowers. 

 G. All of the glumes of each cluster tapering from the base. 

 H. Leaf blades finely pubescent; inner glumes of the lateral spikelets about 

 twice as long as the outer. U. H. gussoneanum 

 HH. Leaf blades scabrous; both glumes of the lateral spikelets about the 

 same width. W. E. H. nodosum (wild barley) 

 GG. 3-4 of the glumes of each cluster widest above the base. 

 i. Leaves rough above, smooth beneath; spikes 4-6 times as long as wide. E. 



H. pusUlum (little barley) 

 n. Leaves smooth on both sides; spikes 2-3 times as long as wide. U. 



H. geniculatum (sea barley) 

 CC. Heads exclusive of awns about 10 mm. wide. E. — Cultivated for grain. 



H. distlchon (2-ROw barley) 

 AA. All 3 spikelets of each group fertile. W. E. — Cultivated for grain. 



H. hezastlchon (6-eow barley) 



r. A R. EL. FL. — 4 



