PART II. 
EXOTIC TREES AND SHRUBS. 
We have already given descriptions and illustrations of several 
exotic species in Part I., where it seemed more advantageous 
to the reader to include them with British species of the same 
genus ; those now to be dealt with are in all cases members of 
genera not represented in our native Flora. 
The Plane {Platanus orientalis). 
In spite of the fact that the Plane is an exotic of compara- 
tively recent introduction, it seems in a fair way of being asso- 
ciated in the future with London. It has taken with great 
kindness to London life, in spite of the drawbacks of smoke, 
fog, flagstones, and asphalt. Its leaves get thickly coated with 
soot, which also turns its light-grey bark to black ; but as the 
upper surface of the leaves is smooth and firm, a shower of rain 
washes them clean, and the rigid outer layer of bark is thrown 
off by the expansion of the softer bark beneath. This is not 
thrown off all at once, but in large and small flakes, which leave 
a smooth yellow patch behind, temporarily free from soot con- 
tamination. A variety of trees has been tried for street-planting, 
but none has stood the trying conditions of London so well as 
