PLANTS OF THE SAN BERNARDINO MOUNTAINS 



167 



feet altitude, and the Upper Chaparral thence to the ridge 

 Une. The former subzone is characterized by such shrubs as 

 Adenostoma fasciculatum, along its lower limits, and above by 

 Juglans californica, Ceanothus crassifoUus, and C. divaricatus; 

 the Upper by Pseudotsuga macrocarpa, U mbellularia californica 

 and Ceanothus integerrivius. 



The opposite, or desert slope is also overgrown with shrubs, 

 but of species entirely different from those found on the southern 

 side. It is designated the Piiion Zone, and its altitudinal Umits 



Fig. 2. Forest of yellow pine in the Lower Transition Zone 



are between 3500 or 4000 to 6000 or 7000 feet in various parts. 

 Among its notable plants are Pinus. vionophylla, Fremontia 

 californica and Ceanothus Greggii. The subzones are not well 

 distinguished, but such plants as Salvia pilosa, Purshia glandulosa 

 and Pentstemon Eatoni are found only in the Lower, and Brick- 

 ellia oblongifolia linifvlia, Malvastrum Davidsonii and Caidanthus 

 crassifoUus glaber only in the Upper. The canons of this slope, 

 that of the Mojave River excepted, are without permanent streams, 

 save occasionally for short distances, and even springs are in- 

 frequent; but their flora is more abundant and more varied than 



