774 GRAMINE.E lolidm 



AGROPYRON 



empty in the lateral spikelets and the two lower ones empty in 

 the terminal one : flowering glumes rounded on the back, 5-7- 

 nerved : palets 2-keeled. Stamens 3. Styles distinct, very short, 

 with plumose stigmas. Grain adherent to the palets. 



L. perenne L. Sp, 83. Stems 6-30 inches high, erect, simple, smooth, 

 from a perennial root: sheaths shorter than the internodes: ligules very 

 short : leaves 2-5 inches long : 1-2 lines wide, spike S-8 inches long : spike- 

 lets 5-10 flowered, 4-6 lines long, empty glumes shorter than the spikelets, 

 strongly nerved ; flowering glumes 2-3 lines long, obscurely nerved, acumin- 

 ate or awned, the awn sometimes nearly as long as the glume. Common 

 in waste places: naturalized from Europe. 



L. temulentum L. Sp. 83. Glabrous throughout: stems 2-4 feet high, 

 erect, simple, from an annual root: sheaths longer than the internodes: 

 ligules aline long or less: leaves 4-10 inches long, 1-3 lines wide, smooth 

 beneath, rough above : spike 4-12 inches long : spikelets 4-8-flowered, 5-9 

 lines long, the strongly nerved empty glumes equalling or exceeding the 

 obscurely nerved flowering ones. In fields : naturalized from Europe. 



52 AGROPYRON J. Gsertn. Nov. Comm. Petrop. xiv, pt. 1, 539. 



Annual or perennial grasses with flat or involute leaves and 

 terminal spikes. Spikelets 3- to several-flowered, sessile, solitary 

 and alternate at each notch of the usually continuous rachis, the 

 side of the spikelet turned toward the rachis. Glumes rounded 

 on the back, the two lower empty : flowering glumes rigid, rough 

 on the back, 5-7-nerved, usually acute or awned at the apex. 

 Palets 2-keeled. Stamens 3. Styles very short, distinct. Stigmas 

 plumose. Grain pubescent at the apex, usually adherent to the 

 palet. 



A. divergens Nees in Steud. Syn. PI. Gram. 347. A slender densely 

 tufted glaucous perennial 1-3 feet high: lower sheaths longer than the 

 internodes, upper ones shorter: ligules very short: basal leaves numerous, 

 4-12 inches long: those of the stem 2-4 inches long, all more or less convol- 

 ute and setaceous, nearly smooth: spikelets 3-8 inches long, slender: 

 spikelets 3-6-flowered; first empty glumes 3 lines long, 3-nerved, the mar- 

 gins scabrous; the second 4 lines long, 5-nerved, with the midrib at one 

 side, awnless ; flowering glumes, 4-5 lines long, plainly 5-nerved above : 

 awn stout, diverging or recurved, longer than the glumes. Common on 

 dry plains east of the Cascade range. Brit. Columbia to California and 

 the Kocky Mountains. 



Var. inermis Scribn. & Smith U.. S. Dept. Agr. Div. Agrost. Bull. 

 4, 27. ^ Empty glumes unequal, narrowly lanceolate, acute, 4-6 lines long ; 

 flowering glumes 5-6 lines long, smooth : acute, or acuminate, awnless or 

 with a straight or spreading awn shorter than the glume. Eastern Wash- 

 ington to Brit. Columbia and Idaho. 



Var. tenuispicatum Scribn. & Smith 1. c. Stems 2-3 feet high : 

 leaves very narrow, spikes slender, flexuous, 3-6 inches long : spikelets 5-7 

 lines long: awns 5-9 lines long, slender, straight, curved or divergent. On 

 high dry plains, eastern Oregon to Brit. Columbia, Montana and Wyoming. 



A, Vaseyi Scribn. & Sm. 1. c. Stems rigid, erect, wiry, 1-1^ feet high, 

 glabrous, or glaucous : sheaths glaucous, shorter than the internodes: 

 ligules very short, leaves minutely strigose-pubescent above, rigid, 1-6 

 inches long, 1 line or less wide : spikes very slender, 2-4 inches long : 

 spikelets 4-5 lines long, 3-5-flowered : empty glumes oblanceolate, acute 



