80 GRAMINEAE (GRASS FAMILY) 



8-25 cm. long, 2-8 mm. wide: spikes erect or nodding at the top, often one- 

 sided, 8-20 cm. long, light green or the empty glumes and awns often pur- 

 plish: spikelets 4-8 mm. distant, 3-6-flowered: glumes about as long as the 

 spikelet, linear-lanceolate, acuminate, tipped with an awn 2-8 mm. long, 

 3-5-nerved, scarious on the margins, scabrous or nearly smooth, 7-9 mm. 

 long; lemma smooth on the back below, scabrous and 5-nerved above, ex- 

 tended into a slender awn 2-3.5 mm. long, often bidentate below the origin 

 of the awn. Throughout our range. 



4. Agropyron violaceum (Hornem.) Lange, Consp. Fl. Greenland 154. 

 1880. Erect, tufted, 3-9 dm. high: leaves scabrous or sometimes smooth be- 

 neath, 5-20 cm. long, 2-6 mm. wide: spikes comparatively stout, 3-10 cm. 

 long: spikelets 3-8 mm. distant, 3-5-flowered: glumes usually purplish, nar- 

 rowly oblong to oblong-linear, acute, rather thin, usually broadest above the 

 middle, obtuse and toothed at apex, scarious on the margins, 3-7-nerved, sca- 

 brous, 8-13 mm. long; lemmas acuminate or tipped with a short weak awn, 

 the awn rarely as long as the body, often purplish. Throughout our range and 

 northward. 



4a. Agropyron violaceum andinum Scribn. & Smith, U. S. Dept. Agr. Div. 

 Agrost. Bull. 4: 30. 1897. Densely tufted, 20-45 cm. high: spikes short and 

 compact: the awns as long or longer than the flowering glumes. High moun- 

 tains of Colorado. 



5. Agropyron Bakeri E. Nels. Bot. Gaz. 38: 378. 1904. Smooth, tufted, the 

 culms stout, 3-5 dm. high: leaves flat, rigid, prominently striate-nerved; those 

 of the culms 12-20 cm. long, 2-4 mm. wide, those of the innovations some- 

 what longer: spikes scarcely exserted, equaled or exceeded by the uppermost 

 leaf, 9-12 cm. long: spikelets terete, 5-9 mm. distant, 5-flowered, 15-19 mm. 

 long: glumes two thirds as long as the spikelets, narrowly oblong, somewhat 

 abruptly narrowed into an awn 2-8 mm. long and with or without a tooth at 

 the base of the awn, 5-nerved, scabrous, 11-12 mm. long; lemma scabrous, or 

 nearly smooth, the strong mid-nerve extended into a rigid widely spreading 

 awn 10-35 mm. long, often bidentate below the origin of the awn. Southern 

 Colorado. 



6. Agropyron Gmelini (Griseb.) Scribn. & Smith, U. S. Dept. Agr. Div. 

 Agros. Bull. 4. 30. 1897. A rather slender, glabrous, tufted perennial 6-12 

 dm. high: leaves flat, glabrous below, scabrous above; the basal ones 2-8 cm. 

 long, 4-6 mm. wide; those of the culm much longer: spikes slender, 10-25 cm. 

 long: spikelets 6-20, somewhat crowded, subterete or compressed, 5-9- 

 flowered: glumes two thirds as long as the spikelet, oblong-lanceolate, acumi- 

 nate and short awned, 10-14 mm. long; lemma acuminate, awned from or 

 just below the apex with a slender, divergent scabrous awn 16-30 mm. long. 

 Moist soil, mountains; Washington to western Wyoming. 



6a. Agropyron Gmelini Pringlei Scribn. & Smith, 1. c. 31. Low and tufted, 

 2-3 dm. high: leaves rigid, glaucous below, strigose above, 5-10 cm. long: 

 spikes loose, few-flowered. High mountains; Wyoming and California. 



7. Agropyron tenerum Vasey, Bot. Gaz. 10: 258. 1885. A slender, tufted, 

 glabrous perennial, 6-9 dm. high: sheaths glabrous; leaf -blades narrow, flat or 

 involute, scabrous, 7-25 cm. long, 2-5 mm. wide: spikes slender, cylindrical, 

 8-18 cm. long: spikelets usually erect and appressed to the rachis, 5-10 mm. 

 distant, 3-5-flowered. glumes from about as long as the spikelets to two 

 thirds their length, usually broader below the middle, linear-lanceolate or 

 narrowly oblong, acute or acuminate, often awn-pointed, scarious on the 

 margins, 3-5-nerved and scabrous on the back, 8-12 mm. long; lemma smooth 

 or smoothish on the back below, scabrous and 5-nerved above, muticous or 

 tipped with a stiff straight awn 1-4 mm. long. Sandy soil, throughout our 

 range. 



7a. Agropyron tenerum ciliatum Scribn. & Smith, U. S. Dept. Agr. Div. 

 Agros. Bull. 4: 30. 1897. Sheaths pubescent or the lower ones densely 

 hairy. Minnesota to Utah. 



8. Agropyron pseudorepens Scribn. & Smith, U. S. Dept. Agr. Div. Agrost. 

 Bull. 4: 34. 1897. Erect and rather stout, light green, with or without creep- 



