THE GENERAL PLAN OR THEORY OF THE PLACE 43 
men trees than to using in composition, — that is, as parts of 
general groups of trees, where their characters serve to break 
the monotony of heavier forms and heavier foliage. The 
poplars are gay trees, as a rule, especially those, like the aspens, 
that have a trembling foliage. Their leaves are bright and 
the tree-tops are thin. The common aspen or ‘‘popple,”’ 
Populus tremuloides, of our woods, is a meritorious little tree 
for certain effects. Its 
dangling catkins (Fig. 
33), light, dancing fo- 
liage, and silver-gray 
limbs, are always 
cheering, and its au- 
tumn color is one of the 
purest golden-yellows 
of our landscape. It 
is good to see a tree 
of it standing out in 
front of a group of 
maples or evergreens. 
OREM AM ae 
Plant-forms. Malic sco 
Before one attains 
to great sensitiveness 
in the appreciation of gardens, he learns to distinguish plants by 
their forms. This is particularly true for trees and shrubs. Each 
species has its own ‘‘expression,’’ which is determined by the 
size that is natural to it, mode of branching, form of top, twig 
characters, bark characters, foliage characters, and to some extent 
its flower and fruit characters. It is a useful practice for one 
to train his eye by learning the difference in expression of the 
trees of different varieties of cherries or pears or apples or other 
fruits, if he has access to a plantation of them. The differences 
in cherries and pears are very marked (Figs. 34-36). He may 
34. Plant-form in cherries. — Reine Hortense. 
