19 



tliis are other sages, most important among whicli is Bnd brush { Arte- 

 misia spiiicscens). Altogether the most valuable plant, however, is 

 Kuttall's Salt-sage {Atriplex nutfalHi). This constitutes a large part 

 of the forage of the region. With the foregoing must be mentioned 

 Winter Vnt [Eurolid lanata), Shad Scale {Atriplex conferti folia), the 

 Ivabbit- brushes, or Green -sages {(Jhri/.sothamnus), and a few other 

 shrubby plants {Tetradymia, etc.). Besides tliis shrubby vegetation 

 there are a number of grasses that form a somewhat scattering growth. 

 Most prominent among these are the Wheat-grasses [Agropyron) and 

 Indian Millet {Eriocoma cuspidaia). 



Alkali division. — ISText in iini)ortance are the i)lants on the strongly 

 alkaline soil, the land immediately bordering the creeks, the low flats 

 adjacent, and the shallow dry lake beds. Here we find sagebrush 

 largely rei)]aced by Grease- wood {Sarcohatus), and with this a great 

 admixture of Salt sages {Atriplex) and a few species of rushes and 

 sedges. 



P(dudal division. — This includes the oc(;asional spring bogs and creek 

 marshes where occurs a dense growth of grasses, sedges, and rushes, 

 including a large number of species. 



Snowdrift division. — This comi)rises the areas of permanent winter 

 snows, that is, the deep "draws" and abrupt slopes where snowdrifts 

 pile upon snowdrifts. Here, besides Sage brush, are found occasional 

 clumps of Choke-cheiTy, Service berry. Mountain mahogany {Ccrco- 

 earpi(.s), etc., besides a great profusion of herbai-eous vegetation, 

 including many valuable grasses and sedges. 



Cedar-Bluffs division. — On some of the higher or at least the more 

 abrupt hills and slopes occurs a scattering and stunted growth of 

 juiiii)er, a scraggy shrub or small much-brancihed tree. Scattered 

 among the junipers are various small shrubs and occasional patches 



of tine grass. 



DISTINCT TYPES OF VEGETATION. 



In the lu'eceding outline no attempt has been nuide to draw attention 

 to any except the more enduring and therefore the vegetation of most 

 economic importance. To understand the Hora of the region one must 

 consider two somewhat distinct types: 



Persistent vegetation. — Those plants which are more or less in evi- 

 dence throughout the year. 



Transient vegetation. — All those plants which s])ring up each year 

 from seed or from such underground parts as bulbs, tubers, or root- 

 stocks. Most of the plants of this character spring up (piickly, blos- 

 som, bear fruit, wither, and disappear for the rest of the year. Tiiese 

 plants far outnumber the persistent type. This transient vegetation 

 follows close upon the retreating snows. The warm sun of the many 

 bright days of spring and the grateful moisture coax out a few forms in 

 Ai)ril, while in May the wild mustards, beans, chickweeds, composites 



