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UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



record of native-growing black walnut trees until we reach those at 

 Walnut Creek near Mount Diablo, a distance of about three hundred 

 and fifty miles. We have investigated various reports of indigenous 

 trees in this stretch of country, but thus far have found evidence of all 

 such having been planted since the American occupation. 



The southern California trees are considerably different in aspect 

 from those of the north, although individual specimens of each may be 



FIG. 8. Large southern California black walnut tree near roadside between Ventura 



and Nordhoff. 



found which resemble each other quite closely. The southern tree is 

 much more shrubby, frequently branching directly from the ground, 

 and tending to break up into a much branched, broad, low-spreading 

 head even when a single trunk is formed. It is not, as is popularly 

 supposed, a dwarf or slow-growing tree, except in so far as it is influ- 

 enced to develop in this way by the fact that it is able to and frequently 



