BLACK POPLAR. 



GENERAL REMARKS. 



N most trees the leaves are massed together into groups. 

 On the Oak the groups are arranged in tufts, on the 

 Beech in layers ; Ash-foliage makes lace-like patterns. 

 Clear-cut patches of sky are visible between the 

 masses of foliage on the Elm : on the Horse Chestnut the layers are 

 so dense as to be impenetrable to the light. Sometimes the whole 

 tree is a mere leaf-tracery against a background of sky, which peers 

 in through countless apertures : the Birch is a notable example. On 

 the Sycamore the foliage groups have sharply defined edges : on the 

 Willow the edges are blurred. But on all these trees alike, the 

 impression made by the individual leaf is lost in the general effect 

 of a mass of foliage. 



On the Black Poplar each separate leaf stands out and draws 

 attention to itself as a distinct object : each leaf holds its own in 

 the foliage picture. This is accounted for by the size of the 

 leaves and the unusually wide distances between them, and also 

 by the unbroken leaf-margin, so different from that of the Mountain 

 Ash. The blade has neither a very light underside like the White- 

 beam, nor a very reflective upper surface like the Holly, to blend 

 it with the sky. And — foremost reason of all — the leaves hang 



vertically, so that many of them show their whole outline, and this 

 in spite of the inevitable overlapping of branches, foreshortening, and 



