AGROPYBON GRAMINE^E 775 



or acuminate, slightly unequal, scarious along the margins 3-4 lines long : 

 flowering glumes 4 lines long, lanceolate, acute, tipped with a stout div- 

 ergent awn 4-5 lines long. On dry plains, eastern Oregon and Washington 

 to the Rocky Mountains. 



A. caninum Beauv. Agrost. 102. Stems 1-3 feet high, erect, smooth: 

 sheaths usually shorter than the internodes, smooth, or the lower some- 

 times pubescent: ligules short: leaves 3-9 inches long, 1-3 lines wide, 

 smooth beneath rough above: spikes 3-8 inches long, sometimes one- 

 sided, often nodding at the top : spikelets 3-6 flowered : empty glumes 4> -6 

 lines long, 3-5-nerved, acuminate* awn-pointed or bearing an awn. 1-3 

 lines long; flowering glumes 4-5 lines long, usually scabrous toward the 

 apex, acuminate into an awn sometimes twice their own length. Eastern 

 Oregon to Brit. Columbia, New Brunswick and North Carolina: also in 

 Europe. 



A. tenerum Vasey Bot. Gaz. x, 253. Stems 1-3 feet high, erect, often 

 slender, glabrous : sheaths usually shorter than the internodes, glabrous : 

 ligules very short: leaves 3-10 inches long 1-2 lines wide, flat, or involute, 

 rough: spike 3-7 inches long, usually narrow and slender: spikelets 3-5- 

 flowered : empty glumes 4-6 lines long: acuminate or short-awned, 3-5- 

 nerved, scabrous, on the margins: flowering glumes 5-6 lines long, 5- 

 nerved, awn-pointed or short-awned, scarious-margined, often rough toward 

 the apex. On dry plains, easieiu Oregon to Brit. Columbia and 

 Min nesota. 



Var. longifolinm Scribn. & Smith 1. c. 30. Stems 3-4 feet high, 

 smooth, and shining, rigid: leaves involute, nearly as long as the stems, 

 long attenuate- pointed : spike slender, cylindrical, 9-10 inches long: 

 glumes all short-awned. Northwestern California to Brit. Columbia. 



A. brevifolium Scribn. U. S. Dept. Agr. Div. Agrost. Bull, 11, 55. 

 Stems slender, densely cespitose, 12-16 inches high, usually geniculate at 

 the lower nodes, smooth: lower sheaths scabrous and somewhat purplish, 

 smooth: ligules short: leaves l^-3j^ inches long, 1-2 lines wide, 

 very acute, strigose, scabrous above, very smooth beneath: spikelets approx- 

 imate .usually 3-flowered, empty glumes narrowly lanceolate, 2-3-nerved, 

 scabrous on the keel, short-awned; flowering glumes 6 lineslong, 5-nerved, 

 scabrous on the back, short-awned. On mountain sides, eastern Wash. 



A. riolacenm Vasey Spec. Rep. U. S. Dept. Agr. 45. Stems 6-24 

 inches high, erect, smooth : sheaths usually shorter than the internodes : 

 ligules very short: leaves 2-6 inches long, 1-3 lines wide, flat or involute, 

 rough, or sometimes smooth beneath, spikes I-fl inches long, 2-3 lines 

 broad: spikelets 3-6-flowered: empty glumes broad: usually purplish, 

 scabrous-margined, 5-7-nerved, 4-6 lines long, acute, or acuminate, some- 

 times awn-pointed or long-awned: flowering glumes often purplish, 5-7- 

 nerved, scabrous-margined, 4-6 lines long, acuminate or short-awned. 

 Idaho to Alaska and Ontario : also in Europe and Asia. 



A. Scribnerl Vasey Bull. Torr. Bot. Club x, 128. Stems densely 

 tufted, geniculate near the base, slender, 16-30 inches high, sheaths longer 

 than the internodes: ligules obsolete: leaves 1-3 inches long, involute, 

 narrow and rigid : spikes 2-4 inches long: spikelets 3-6-flowered: empty 

 glumes 3-4 lines long, linear-lanceolate, 3-5-nerved, acuminate into a long 

 point: flowering glumes oblong-lanceolate, 4 lines long, smooth, the mid- 

 nerve extended into a strong spreading or recurved awn. On high moun- 

 tains Washington to California and the Rocky Mountains. 



A. Smithii Rydb. A. glaucum of American Authors, not of R. & S. 

 Glabrous: stems rigid, erect, 1-4 feet high: sheathe smooth, shorter than 

 the internodes : ligules very short: leaves rigid, bluish-green, smooth or 

 slightly scabrous beneath, rough-scabrous on the margins, becoming in- 



