512 PKACTICAL BOTANY 



conifers are the giant cedar, 1 red fir, 2 and Sitka spruce. 3 In 

 the bottom lands of Washington, especially along rivers, there 

 are found, besides some conifers, groves of poplar, maple, and 

 ash. In the wettest of these lands occur dense thickets of 

 willows, Western cornel, crab apple, and vine maple. 



Much of eastern Washington has an annual rainfall of 

 not more than ten inches, and is generally covered with sage- 

 brush and with other semi-desert vegetation, although the soil 

 when irrigated is extremely fertile. Southeastern Oregon is 

 in great part a rocky, sterile plateau of volcanic origin, with 

 vegetation consisting largely of sagebrush, dwarf pine, and 

 juniper. 



From the forty-first to the thirty-fifth parallel (beginning 

 a little to the south of the Oregon line) the southern portion 

 of the Pacific slope is characterized by the California ever- 

 green conifers, the sugar pine 4 of the coast region, the yellow 

 pine, 5 and others. Two redwoods are notable among the moun- 

 tain flora, the smaller 6 a very important source of lumber, 

 the larger 7 (big tree or giant redwood) the greatest and most 

 imposing of all trees (Figs. 250 and 260). 



Among the characteristic members of the California flora 

 are many xerophytic shrubs and small trees, in appearance 

 not unlike the abundant thickets of some parts of the Medi- 

 terranean coast region. The California thickets, known as 

 chaparral, contain many leathery-leaved evergreen dicotyle- 

 dons, among them members of the Oak, the Rose, the Sumach, 

 the Heath, the Buckthorn, and the Composite families. 



On account of the long and severe dry season, southern 

 California abounds in deep-rooted and in bulb-bearing plants, 

 many of the latter belonging to the Lily family ; and in and 

 about the deserts are many cacti and other succulent plants, 

 together with numerous xerophytic shrubs which are not 

 succulent. 



1 Thuja plicata. 2 Pseudotsuga mucronata. 3 Picea sitchensis. * Pinus 

 Lambertiana. b P. ponderosa. 6 Sequoia sempervirens. 7 S. Washingtoniana. 



