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FOREST TEEES OF THE PACIFIC SLOPE. 



Lower California. — Near Mexican line (20 miles southeast of Campo, San Diego 

 County, Cal.), and from point a few miles south of boundary it forms forest about 30 

 miles wide, extending over plateau (at middle elevations) ; on Hanson Laguna Range, 

 and southward on San Pedro Martir Range to south end : generally at 4,500 to 6,000 

 feet elevation above single-leaf piiion pine and below Jeffrey pine, completely covering 



Pinus quadrifolia: a, cone; b, seeds. 



lower parts of range, but in higher parts forming belts on both ocean and desert sides. 

 Locally noted at San Matias Spring, 4.000 feet elevation ; mesas near Mattoni ; Rosarito 

 Divide at 5,000 feet ; El Alamo, at 3,500 feet. 



OCCURRENCE. 



On arid mesas, foothills, and east, west, and south slopes. Xot exacting as to moisture 

 and quality of soil. Commonly on well drained, coarse, dry, shallow soils of decomposed 

 granite or limestone. 



