176 Landscape Gardening 



Sycamore, Plane-tree or Buttonwood (Platanus occiden- 

 talis). — Were it not for the disease which attacks this tree 

 it would be among the most desirable for ornamenting large 

 places or roadsides. Its most conspicuous features are the 

 white and ohve patches of its very smooth trunk and branches 

 caused by the annual scaling off of the outer bark. A 

 blight, however, attacks the leaves in the early summer, 

 causing many of them to wither and fall off, but followed by 

 perfect foliage again later in the season. As a result of this 

 disease the branches become weakened and are easily broken 

 off by wind and storm. The sycamore requires a moist 

 rich soil and some very beautiful specimens are found grow- 

 ing in river-bottom lands in many sections of the country. 



Poplars. — Very few, if any, of the poplars are of much 

 value for permanent growth. They are very rapid in 

 growth, easily transplanted, possessing many varying forms 

 and colors, and useful where immediate effect is desired. 



Silver Poplar or Abele {Popiilus alba). — This very 

 rapidly growing tree is especially conspicuous when the 

 silvery under-surface of the leaves is turned up by the wind. 

 It has the fault, however, of throwing up suckers from the 

 roots and is sometimes attacked by insects. To prevent the 

 suckers from gaining strength and becoming troublesome, 

 they should be pulled up, when the shoots separate from 

 the root, and not be cut off at the surface. If cut off at the 

 surface of the ground, the whole root system remains 

 perfect and the buds are ready to start again with renewed 

 vigor. Trees of this species are much more hardy along 

 the coast of New England than more inland. 



Bolles' Silver Poplar (P. alba, var. Bolleana). — This 

 tree is of a more close and spiry growth than the last, with 

 leaves of a darker color above and equally silvery beneath, 

 and though not fully tested under all conditions promises 

 to be more valuable than the common Abele. 



