Xxvi BOTANY. 



Rihes lepanthum and Prunus Andersonii. Ephedra antisyphilUica is likewise 

 abundant westward and especially southward. 



Along the fresh water streams there are some other species prominent 

 as shrubs, especially the willows, Salix longifolia and cordata in several 

 strongly marked varieties, less frequently Rosa llanda, and still more rarely 

 8hepherdia argentea and Ribes aureum. The marshes and margins of the 

 lakes may be green with Jancus Balticus and Scirpus validus or maritimus, 

 or sometimes with Equisetum hiemale, and the coarseness of the meadow 

 herbage tempered to some extent by a growth of Vilfa depauperata or Triti- 

 cum repens. The more generally abundant herbaceous plants upon the foot- 

 hills are in their seasons the grasses Poa tenuifolia and Hordemn jubatum, as 

 also the more persistent Eriocoma cuspidata, with Sisymbrium canescens and 

 Lupinus Jlexuosus, replaced eastward by sericeus. In general the minor flora 

 is marked by a prevalence of species of Astragalus, CEnothera, Gilia, 

 Hydrophyllacece, annual Eriogonece and ligulate and senecioid composites. 



The more generally predominant of the above mentioned shrubby species 

 may be thus arranged approximately in the order of their frequency. 



Predotninant Species. 



Artemisia tridentata. Grayia polygaloides. Eurotia lanata. 



Obione confertifolia. Halostachys occidentalis. Purshia tridentata . 



canescens. Linosyris graveolens. Ephedra antisypliilitica. 



Sarcobatus vermiculatus. Artemisia trifida. Tetradymia canescens. 

 Linosyris viscidiflora. spinescens. 



All of these are strictly western species, Obione canescens and Eurotia 

 alone being found east of the Rocky Mountains upon the plains. Most of 

 them cross the line of the Sierras and appear upon the Pacific slope, and all 

 excepting the two species mentioned and Artemisia trifida and spinescens pass 

 southward to Arizona, New Mexico or Western Texas, and Obione confertifolia 

 into Mexico. Tetradymia and Eurotia are the only ones reported from 

 north of latitude 49°, the one from British Columbia, the other from the 

 Saskatchewan. 



The mountains are in a large measure as destitute of trees as the val- 

 leys, or even more naked from the dwarfed character of the shrubs upon 

 the exposed ridges and summits. There is generally, however, upon limited 

 portions of all but the lowest ranges from the Sierras to the Wahsatch a 

 greater or less supply of Pinus monophylla or Juniperus occidentalis. These 

 are usually scattered over the dry slopes, of low compact habit, rarely ex- 



