STREET AND HIGHWAY PLANTING. 



57 



THE POPLARS. 



The poplars for street trees are at best makeshifts. They are rapid 

 growing trees, reaching maturity quickly and showing rapid signs of 

 decline. They sucker freely and obnoxiously, and fill all the neighbor- 

 ing top soil with fine roots which quickly impoverish the soil. 



The silver poplar (Populus alba} is a tree of considerable beauty, 

 with whitish bark and tremulous leaves with conspicuous white lower 

 surfaces to the shining dark green leaves. Like the other poplars it is 

 short-lived, has brittle wood, and suckers badly. 



Cotton wood (Populus deltoides) resembles the Lombardy poplar in 

 many ways, but has more slender twigs and a more spreading habit of 

 growth. 



Fremont's poplar (Populus Fremontii) is a native species, somewhat 

 like the silver poplar in color, but differing from it in that it becomes a 

 much larger tree. It is especially desirable in the interior valleys, since 

 it thrives there under adverse conditions. 



The Lombardy poplar (P. nigra var. italica) is too well known to 

 need a detailed description. Its peculiar pyramidal style of growth has 

 undeniable charm when well used in roadside and other plantings, but 

 the tree has so many bad family characteristics that it is questionable 

 if its use is advantageous on the streets. It seems probable that it 

 would do better in private plantings where it could receive the constant 

 attention which is necessary for its well-being. 



Figure 27. 



Figure 28. 



THE FLOWERING PLUM AND THE CATALINA CHERRIES. 



The Catalina cherries (Prunus ilicifolia and Prunus integrifolia) 

 (Fig. 27) are quite different as to the style of growth and the shape of 



