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MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



and there in grainfields, Ontario, 

 N rth Dakota, South Dakota, Mon- 

 tana, Wyoming, Colorado, Utah, 

 Nevada, Arizona, and California; ad- 

 ventive, Albany Port, N. Y. Intro- 

 duced from Russia, extensively 

 planted in the northern Great Plains 

 area, and spreading readily by re- 

 seeding. 



Agropyron cristatum (L.) Gaertn. 

 Crested wheatgrass. Spike 2 to 7 

 cm. long; spikelets more widely 

 spreading, the glumes somewhat con- 

 torted, gradually tapering into the 

 awns, these curved, 2 to 5 mm. long. 

 % — Adventive on barrier beach, 

 Fishers Island, N. Y. ; Barton, N. 

 Dak. Introduced from Russia, grown 

 in experiment stations, and a valuable 

 dry-land grass for soil conservation 

 and forage in the northern Great 

 Plains. Sometimes foimd mixed in 

 plantings of A. desertorum. 



Agropyron sibiricum (Willd.) 

 Beauv. Rather smaller with relatively 

 scant foliage; spike 6 to 10 cm. long, 

 the rachis glabrous or nearly so ; spike- 

 lets somewhat spreading, about as in 

 A. desertorum, the glumes and lemmas 

 mucronate or with an awn 1 to 2 mm. 

 long. Ql — Introduced from Rus- 

 sia, grown in a few experiment sta- 

 tions, spontaneous in Idaho (near 

 Boise) and New Mexico (near Gal- 

 lup). Better suited to dry soils. 



Agropyron triticeum Gaertn. An- 

 nual, branching at base; culms slen- 

 der, erect or usually decumbent, 

 mostly 10 to 30 cm. tall; blades flat, 

 mostly less than 10 cm. long, 2 to 3 

 mm. wide; spike oval or ovate, 1 to 

 1.5 cm. long, thick; spikelets crowded, 

 about 7 mm. long; glumes and lem- 

 mas acuminate. O — Absaroka 

 Forest, Mont., Wyoming, Mountain 

 Home, Idaho; Corfu, Wash. Sparingly 

 introduced from southern Russia. 



2. Agropyron repens (L.) Beauv. 

 Quackgrass. (Fig. 307, A.) Green or 

 glaucous; culms erect or curved at 

 base, 50 to 100 cm. tall, sometimes 

 taller, with creeping yellowish rhi- 

 zomes; sheaths of the innovations 



Figtjee 306. — Agropyron desertorum, X 1. (Ball 1768, 

 Colo.) 



often pubescent; blades relatively 

 thin, flat, usually sparsely pilose on 

 the upper surface, mostly 6 to 10 mm. 

 wide; spike 5 to 15 cm. long, the rachis 

 scabrous on the angles; spikelets 

 mostly 4- to 6-flowered, 1 to 1.5 cm. 

 long, the rachilla glabrous or scaberu- 

 lous; glumes 3- to 7-nerved, awn- 

 pointed; lemmas mostly 8 to 10 mm. 

 long, the awn from less than 1 mm. 

 to as long as the lemma; palea obtuse, 

 nearly as long as the lemma, scabrous 

 on the keels. % — Waste places, 

 meadows and pastures, Newfound- 

 land to Alaska (Skagway), south to 

 North Carolina, Arkansas. Utah, and 

 California; Mexico; introduced from 

 Eurasia. Common in the Northern 

 States; a troublesome weed in culti- 

 vated ground. Called also quitch 

 grass and couch grass. Awned speci- 

 mens have been described as Agro- 

 pyron leer si ami m (Wulf.) Rydb.; also 

 referred to A. repens f. aristatum 

 (Schiim.) Holmb. 



3. Agropyron pungens (Pers.) 

 Roem. and Schult. (Fig. 307, B.) 

 Glaucous, culms 50 to 80 cm. tall, 





