$822 THE POPLAR. 
interesting in the landscape ; standing alone as a lawn tree, it 
assumes a pendulous form. On the outskirts of plantations, 
or when the species is grouped by itself, and seen either on 
the hill top or on the sloping sides of the forest, it forms an 
object of great interest. Its foliage forms a contrast with 
most other trees throughout thé summer, being of a beautiful 
glaucous green, which, after the first frosts of autumn, changes 
into a fine mellow or ripened hue, and ultimately into a bright 
yellow. The trunk of advanced growth is of an ash colour. 
With tasteful arrangement, this tree, being perfectly hardy, 
forms a valuable element in embellishment, at any altitude 
adapted for arborescent vegetation. The trembling of the 
leaves is far more conspicuous in this than in any other species 
of the poplar, arising from the construction of the leaf and 
petiole, or leaf-stalk. The leaves are round and smooth, and 
stand on long slender foot-stalks, which cause them to become 
agitated by the slightest impulse of the air, so that their 
quivering is quite perceptible, and well heard, during weather 
comparatively calm— 
«When zephyrs wake, 
The aspen’s trembling leaves must shake.” 
In the English Flora, Sir J. E. Smith says,—* The colour 
of the upper surface of the leaves is a fine dark glaucous 
shining green, and that of the under surface of a paler shade. 
The disk of the leaf has a small point, and three ribs. It is 
somewhat wavy, and often shorter than the foot-stalk, which, 
being vertically compressed in its upper part in relation to the 
plane of the leaf, counteracts the ordinary waving motion of 
the leaf in the wind, and causes it to quiver with the slightest 
breeze.” 
It is worthy of notice that no tree so interesting, ornamental, 
and hardy, is so sparingly planted throughout Britain, so it is 
not often to be seen in the nurseryman’s catalogue. The wood 
is the strongest, hardest, and heaviest of the poplars; and the 
bark is sometimes used in tanning leather. 
P. Fastigiata, the Fastigiate or Lombardy Poplar, is a well- 
known. tall tree, readily distinguished from every other species 
