THE POPLAR. 321 
grown in the country, to the extent of about fourteen or six- 
teen sorts; and, after six years’ growth, this tree, the grey 
poplar, is very far ahead of every other sort, both in height 
and girth, and already assumes a timber-tree appearance ; 
showing that a disturbed or loose surface soil in the vicinity 
of water is an element favourable to the most rapid growth of 
this tree, as it is to every other species of poplar. 
P. Tremula, the Trembling-leaved Poplar, or Aspen, is 
indigenous to Britain, and to mountainous situations through- 
out Europe and Asia. Throughout the Highlands of Scotland 
it is frequently associated with the natural birch. It is a 
beautiful tree, of a stately and elegant appearance, round- 
headed, and tall in proportion to its girth, of rapid growth, and 
extremely hardy. It attains a considerable height in almost 
any description of soil, growing luxuriantly when young in a 
soil dry and sandy, as well as in that which is wet and strong. 
The roots of the aspen spread over the surface of the ground, 
and when the vigour of the young tree subsides, the greatest 
objection to its cultivation in many situations is its propensity 
to produce suckers from the roots, which, in neglected grounds, 
form a jungle around the tree. 
In the Highlands, the young shoots are greedily eaten by 
sheep and cattle; and for this purpose, in Germany and 
Sweden, the spray is frequently used both in a green and 
dried state ; and, according to one writer, this is the most 
valuable purpose to which it can be applied. The seeds of 
the tree ripen in summer, and may be immediately sown ; but 
propagation by layers, or suckers, is the more speedy method. 
This species grows freely from cuttings of the roots, but not 
from cuttings of the branches. Plants one or two years trans- 
planted from layers are commonly from five to six feet high, 
when they should be removed from the nursery. In soil of 
ordinary quality, the average growth of the aspen for the first 
ten years is not under three feet annually. One of the loftiest 
trees of the species in Britain is reported to stand at Castle 
Howard, in Yorkshire, 130 feet high, with a trunk three and 
a half feet in diameter. Few trees are more ornamental or 
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