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Pomona College Journal of Economic Botany 



to excel. This tree will turn a barren, sun-beaten street into an inviting, 

 shady lane so effectively and in so short a time tliat we should not bar it 

 from our midst for a few minor faults. 



In close competition with the pepper, probably exceeding it in iiuiiibers, is 

 the Eucalypt in a number of species, tlie most usual of whidi is the blue gum 

 {Eucalyptus globulus). This is a very rapid, tall tirovving tree that adapts 

 itself well to the atmospheric conditions of the sea coa.st. At the same time, 

 it makes an attractive avenue tree where ample space permits its development, 

 and when planted on an avenue of sufficient width to bear well its height. 



In our hot inland valleys, the blue gum is sujjplanted by the manna gum 

 {E. I'imiiialis) wliich grows almost as fast as the former, standing at the 

 same time a much wider range of temperature and thriving where the blue 

 gum will not exist. After a few years, its brandies assume a pendulous 

 position that gives to the tree a very pleasing grace and case of carriage. It 

 is seldom seen as a .street tree, but is well suited for planting along our 

 country roads where it has space for its rugged development. 



Another tree that siiould prove desirable for country road i)hinting, in 

 districts that are not visited by heavy frosts, is the Morcton Hay fig {Firus 

 macrophylla) , a tree that attains an ultimate heiglit of 100 feet with a spread 

 even wider. Due to the buttressing habit of the roots and to its immense size, 

 it is not suitable for general city planting but would make a most majestic 

 avenue tree, where room permitted. The native live oak {Quercus agrifolia) 

 and the cork oak {Q. suher) are quite similar in general appearance, although 

 the cork oak grows more erectly and more rapidly than tiic common live oak. 

 Both of them make admirable avenue trees when matured, but because of their 

 slow- growth are often rejected by planters. It would seem, however, that 

 we are planting trees for the coming generations as well as for the present, 

 so that a mere inatter of slow growth should not bar a tree that is so beautiful 

 and serviceable as the oak. 



A tree that I have never seen on a street, but which would look well on 

 a country road of average width, is the native Island iron-wood, {Lyono- 

 thamnus floribundus, var. asplcnifoUus) . This tree is wonderfully tolerant 

 of drought and the steady cold trade winds of our coast. It has a fernlike 

 foliage and white flower clusters, both drooping gracefully. It produces a 

 hard durable wood that is not easily broken by winds; .so that all in all it 

 seems to fulfill remarkably well the tests of endurance that are levied upon 

 a street tree. 



Although one might need to protect such fruiting trees with the national 

 guards or at least a burglar proof fence, the avocado {Persea gratissima) 

 would make a beautiful, shade-producing street tree. Its foliage is of a bright 

 lustrous green. Its habit of growth is large and spreading. It is a rare 

 fruit tree. But as Germany has made a successful practice of planting fruit 

 trees along her highways, which were thus made to pay for their own upkeep 

 through the harvest and sale of their fruit, why could not Californians show 



