THE NORTH TEMPERATE ZONE 123 



spiraea, etc., and herbaceous plants, like asters, golden-rod, willow- 

 herb, and others. 



Along the railway in Utah and Nevada as far as one can see, is 

 a monotonous landscape of barren plains and low hills sometimes 

 almost destitute of vegetation, but usually covered with a dull- 

 green mantle of sage-brush which is the predominant plant of this 

 region. Between the clumps of sage-brush, there are often scat- 

 tered tufts of grass, and sometimes after spring rains, various 

 flowers appear for a brief season. Among these may be mentioned 

 the "sego lily" of Utah, a pretty lily of the genus Calochortus; 

 evening primrose, lupins, and various other showy annuals. 



When the soil is strongly alkaline, grease-wood (Sarcobatus 

 vermicularis) takes the place of the common sage-brush, and with 

 it occur other plants characteristic of alkaline soils, e. g., Atriplex, 

 Bigelovia, Suaeda and others. 



This dreary landscape continues almost to the foot of the 

 Sierras, where the effect of the coastal moisture begins to make 

 itself manifest. 



This arid region extends northward into Oregon and Washington, 

 where desert conditions are less extreme, and the northern portion 

 of the Great Basin is traversed by the Columbia which breaks 

 through the Cascade mountains and reaches the sea. A con- 

 siderable portion of the Columbia basin lies in this arid region, and 

 although much of it is very dry, there is a true forest growth in 

 many places, and even at the lower elevations the yellow pine may 

 form open forests. Only a small area in eastern Washington is 

 comparable to the deserts of Nevada and Utah. 



The desert of the Great Basin has a much more monotonous 

 vegetation than the regions to the south. The Cacti, Yuccas, 

 and other striking forms of the deserts of Arizona and southern 

 California, are almost entirely absent. These are of Mexican 

 origin, and apparently not fitted for the severe winters of the 

 northern desert. 



Of course, even in a true desert region, the sheltered valleys, 

 watered by mountain streams, may develop a relatively luxuri- 

 ant vegetation, and if sufficiently open are available for cultiva- 

 tion. Before reaching Ogden, the railway passes through the can- 

 yon of the Webber River, which furnishes water for irrigation, and 

 where the floor of the valley expands there are prosperous looking 



