35 



Sporobolus cryptandrus A. Gray (Sand Dropseed). — A tufted form with spread- 

 ing- stems, 12 to IS incbfs long, occurring on sandy knolls and ridges; usually 

 of very scattering growth, so that, thougli it is a nutritious jjasture grass, it is 

 of small economic importance. Hillsdale, July 7 (3660) ; Laramie, July 20 (3417). 



Sporobolus depauperatus Scribn. (Dkopsekd). — Somewhat tufted, but still form- 

 ing a continuous sod, stems and leaves slender, 6 to 12 inches high. A most 

 excellent pasture giass. Centennial Valley, July 2 (3274); Evanston, July 27 

 (3841); Granger, July 30 (3883); Johnson's Ranch, August 8 (3901); Grand 

 Encampment Creek, August 13 (4002); Wagon Hound Creek, August 21 (4403). 



Sporobolus simplex Scribn. — 

 A tiny alpine form, growing 

 in little tufts, or sometimes 

 as small patches of uniform 

 sod; the fruiting heads slen- 

 der and few-seeded ; the fine 

 root-leaves numerous and 

 nearly as long as the capil- 

 lary stems, which are 2 to 4 

 inches high. It occurs on the 

 uaked slopes in the vicinity 

 of the permanent winter 

 snow banks. Battle Lake 

 Mountain, August 16 (4011). 



Agrostis alba L. (Red top, 

 Herd's-grass). — This well- 

 known grass occurs through- 

 out the valleys of the whole 

 region investigated. In 

 many places it has no doubt 

 been introduced, but in some 

 of the localities where it was 

 secured it must have been in- 

 digenous. It prefers wet 

 ground, and thrives im- 

 mensely under irrigation. In 

 some of the valleys it is con- 

 sidered one of the important 

 meadow grasses, as, for in- 

 stance, at Evanston, in the 

 Bear River Valley. Hills- 

 dale, July 7 (3663); Evans- 

 ton, July 27 (3832 and 4444) ; 

 Granger, July 30 (3888); 

 Grand Eiuampment Creek, 

 August 13 (3995). fig.6.. 



Agrostis asperifolia Trin. 



(ROUGII-LK AFED BeNT- 



GRASS). — An erect grass with long heads and numerous, ample leaves. It prefers 

 wet ground, such as the banks of streams, partially shaded l>ottom lands, and 

 more rarely boggy ground. It is a valuable constituent of the forage in such 

 situations, and forms a part of the hay in wet meadows. Evanston, July 28 

 (3856) ; Woods Creek, August 9 (3964). 

 Agrostis scabra Willd. (Rough Hair-grass). — Erect, with slender leaves and stems 

 and narrow, or, in older specimens, widely spreading panicle, the pedicels 

 extremely long and hair like. It forms a small part of the native grasses on 

 most of the bottom lands; occurring as scattering specimens or small clumps, 

 most frec^uent in the loamy soil of stream banks, probably of little value, but 



-Fine- top Salt-grass (Sporobolus airoides) : a, spike- 

 let; 6, floret. 



