While Nature, in the forms of trees, in the color of their foliage and
the gracefulness of their spray, has displayed a great variety of
outline and tinting, and provided a constant entertainment for the
sight, she has increased their attractions by endowing them with a
different susceptibility to motion from the action of the winds. In
their motions we perceive no less variety than in their forms. The
different species differ like animals; some being graceful and easy,
others stiff and awkward; some calm and intrepid, others nervous and
easily agitated. Perhaps with stricter analogy we might compare them to
human beings; for we find trees that represent the man of quiet and
dignified deportment, also the man of excited manners and rapid
gesticulations. Some trees, like the fir, having stiff branches and
foliage, move awkwardly backward and forward in the wind, without any
separate motions of their leaves. While we admire the symmetrical and
stately forms of such trees, we are reminded of men who present a noble
personal appearance, accompanied with ungainly manners.
Some trees, having stiff branches with flexible leaves, do not bend to a
moderate breeze, but their foliage readily yields to the motion of the
wind. This habit is observed in the oak and the ash, in all trees that
have a pendulous foliage and upright or horizontal branches. The poplars
possess this habit in a remarkable degree, and it is proverbial in the
aspen. It is also conspicuous in the common pear-tree and in the small
white birch. Other trees, like the American elm, wave their branches
gracefully, with but little apparent motion of their leaves. We observe
the same habit in the weeping willow, and indeed in all trees with a
long and flexible spray. The wind produces by its action on these a
general sweeping movement without any rustle. It is easy to observe,
when walking in a grove, that the only graceful motions come from trees
with drooping branches, because these alone are long and slender.
The very rapid motion of the leaves of the aspen has given origin to
some remarkable superstitions. The Highlanders of Scotland believe the
wood of this tree to be that of which the holy cross was made, and that
its leaves are consequently never allowed to rest. Impressed with the
awfulness of the tragedy of the crucifixion, they are constantly
indicating to the winds the terrors that agitate them. The small white
birch displays considerable of the same motion of the leaves; but we
take little notice of it, because they are softer and produce less of a
rustling sound. The flickering lights and shadows observed when walking
under these trees, on a bright noonday, have always been admired. All
these habits awaken our interest in trees and other plants by
assimilating them to animated things.
Much of the beauty of the silver poplar comes from its glittering
lights, when it presents the green upper surface of its foliage,
alternating rapidly with the white silvery surface beneath. This we may
readily perceive even in cloudy weather, but in the bright sunshine the
contrasts are very brilliant. In all trees, however, we observe this
glittering beauty of motion in the sunshine. The under part of leaves
being less glossy than the upper part, there is in the assemblage the
same tremulous lustre that appears on the rippled surface of a lake by
moonlight.
We observe occasionally other motions which I have not described, such
as the uniform bending of the whole tree. In a strong current of wind,
tall and slender trees especially attract our attention by bending over
uniformly like a plume. This habit is often seen in the white birch, a
tree that in its usual assemblages takes a plumelike form. When a whole
grove of white birches is seen thus bending over in one direction from
the action of a brisk wind, they seem like a procession of living forms.
In a storm we watch with peculiar interest the bending forms of certain
tall elms, such as we often see in clearings, with their heads bowed
down almost to the ground by the force of the tempest. It is only the
waves of the ocean and the tossing of its billows that can afford us so
vivid an impression of the sublimity of a tempest as the violent swaying
of a forest and the roaring of the winds among the lofty tree-tops.
The motions of an assemblage of trees cannot be observed except from a
stand that permits us to look down upon the surface formed by their
summits. We should then perceive that pines and firs, with all the
stiffness of their branches, display a great deal of undulating motion.
These undulations or wavy movements are particularly graceful in a grove
of hemlocks, when they are densely assembled without being crowded. It
is remarkable that one of the most graceful of trees belongs to a family
which are distinguished by their stiffness and formality. The hemlock,
unlike other firs and spruces, has a very flexible spray, with leaves
also slightly movable, which are constantly sparkling when agitated by
the wind. If we look down from an opposite point, considerably elevated,
upon a grove of hemlocks when they are exposed to brisk currents of
wind, they display a peculiar undulating movement of the branches and
foliage, made more apparent by the glitter of their leaves.
The surface of any assemblage of trees when in motion bears a close
resemblance to the waves of the sea. But hemlocks represent its
undulations when greatly agitated, without any broken lines upon its
surface. Other firs display in their motions harsher angles and a
somewhat broken surface of the waves. We see the tops of these trees and
their extreme branches awkwardly swaying backwards and forwards, and
forming a surface like that of the sea when it is broken by tumultuous
waves of a moderate height. The one suggests the idea of tumult and
contention; the other, that of life and motion combined with serenity
and peace.