636 POACE^. 



mm. long, with 3 strong nerves, short-awned, second 11 mm. long, 

 with 5 very strong nerves, awn 5 mm. long; floral glume 8-9 mm. 

 long, with 5 obscure nerves, awn about 2 mm. long; palea shorter 

 than its glume, with 3 ciliate nerves. Grain adherent. 



Montana, Scrihner 422, the type; Colorado, Cassidy, Vasey; 

 Iowa, Hitchcock; northern Michigan, Beal. 



The sj^ecific name unilaterale had been used before Cassidy ap- 

 plied it to this species. 



2. A. dasystachyum (Hook.) Scribn. Bull. Torr. Club, 10:78 

 (1883); Vasej', Grasses U. S., Sj^ecial Eept. TJ. S. Dept. Agr. 

 No. 63, 45 (1883). Triticum repens var. dasystachyum Hook Fl. 

 Bor. Am. 2 : 254 (1840), teste A. Gray. T. dasystachyum A. Gray, 

 Man. Ed. 1, 602 (1848). 



A smooth glaucous perennial, 60-90 cm. high, with slender 

 rootstocks having internodes 3-4 cm. long. Leaves of sterile 

 shoots numerous, blades involute, 30-40 cm. long, 2-4 mm. wide, 

 those of the culm 3-4 in number, sheaths nearly as long as the inter- 

 nodes; ligule a mere ring; blades 6-12 cm. long. Spike exserted, 

 14-20 cm. long, joints of rachilla 1 cm. long, or near the base longer. 

 Spikelets narrow, 2 or more cm. long, 5-9-flowered; emjjty glumes 

 smooth or puberuleut, first 7 mm. long, 3-nerved, second 10-12 mm. 

 long, 5-nerved; floral glume 11 mm. long, soft-hairy throughout, 

 awnless or with short awns, margins scarious. Abnormal or thrifty 

 plants bear branching spikes. 



Michigan, Wheeler 156, 157, 158, Beal 158, 159. 



Shores of the Great Lakes, British America and the Eocky 

 Mountains. 



3. A. repens (L.) Beauv. Agrost. 102 (1812). Quick-, Couch-» 

 Quack-, Twitch-Grass. Triticum repens L. Sp. PI. 86 (1753). 



A smooth pale green or glaucous perennial, very variable, 

 30-120 cm. high, with the internodes of the rootstock 1-1.5 cm. 

 long. Ligule very short; blades flat, scabrous, 5-10 mm. wide, the 

 upper 10-20 cm. long. Spike 6-20 cm, long, erect or bending, 

 mostly rigid, joint of rachis 5-15 mm. long. Spikelets 10-20 mm. 

 long, 2-8-flowered, florets at the middle of the spike overlapping 

 for three-fourths of their length or more; empty glumes each un- 



