The Western Plane was first introduced into England about 1630, and was afterwards so generally planted, in consequence of its easy propagation by cuttings and rapid growth, that it soon became more common than P. orientalis. This tree is now, however, rare in this country, from the greater number having been killed by a severe frost in May 1809, and by the severe winter of 1813-4.
The American Plane, in magnitude and general appearance, closely resembles the oriental plane. The one species, however, can always be distinguished from the other by the following characters:—In the Oriental Plane, the leaves are smaller and much more deeply lobed than in the Western tree, and the petioles of the leaves, which in the Oriental species are green, in the American tree are purplish-red; the fruit, or ball-shaped catkins, also, of the Western Plane, are considerably larger, and not so rough externally as those of the other. The bark is said to scale off in larger pieces, and the wood to be more curiously veined. In all other respects, the descriptive particulars of both trees are the same. According to Michang, the Western Plane is "the loftiest and largest tree of the United States." In 1802, he saw one growing on the banks of the Ohio, whose girth at four feet from the ground, was 47 feet, or nearly 16 feet in diameter. This tree, which showed no symptoms of decay, but on the contrary exhibited a rich foliage and vigorous vegetation, began to ramify at about 20 feet from the ground, a stem of no mean length, but short in comparison to many large trees of this species that he met with, whose boles towered to a height of 60 or 70 feet without a single branch. Even in England, specimens of the Western Plane, of no great age, are to be met with 100 feet in height. The rate of growth of P. occidentalis, when placed near water, is so rapid, that in ten years it will attain the height of forty feet; and a tree in the Palace Garden at Lambeth, near a pond, in twenty years had attained the height of eighty feet, with a trunk eight feet in circumference at three feet from the ground, and the diameter of the head forty-eight feet. This was in 1817.—(See Neill's Hort. Tour, p. 9.)
As a picturesque tree, Gilpin places the Occidental Plane after the oak, the ash, the elm, the beech, and the hornbeam, which he considers as deciduous trees of the first rank; saying of both species of Platanus, that, though neither so beautiful nor so characteristic as the first-named trees, they are yet worth the notice of the eye of the admirer of the picturesque.
Leaves and Flowers of P. occidentalis.
"The Occidental Plane has a very picturesque stem. It is smooth, and of a light ash colour, and has the property of throwing off its bark in scales; thus naturally cleansing itself, at least its larger boughs, from moss, and other parasitical encumbrances." This would be no recommendation of it in a picturesque light, if the removal of these encumbrances did not substitute as great a beauty in their room. These scales are very irregular, falling off sometimes in one part, and sometimes in another; and, as the under bark is, immediately after its excoriation, of a lighter hue than the upper, it offers to the pencil those smart touches which have so much effect in painting. These flakes, however, would be more beautiful if they fell off in a circular form, instead of a perpendicular one: they would correspond and unite better with the round form of the bole. "No tree forms a more pleasing shade than the Occidental Plane. It is full-leafed, and its leaf is large, smooth, of a fine texture, and seldom injured by insects. Its lower branches shooting horizontally, soon take a direction to the ground, and the spray seems more sedulous than that of any tree we have, by twisting about in various forms, to fill up every little vacuity with shade. At the same time, it must be owned that the twisting of its branches is a disadvantage to this tree, as it is to the beech. When it is stripped of its leaves, and reduced to a skeleton, it has not the natural appearance which the spray of the oak, and that of many other trees, discovers in winter; nor, indeed, does its foliage, from the largeness of the leaf and the mode of its growth, make the most picturesque appearance in summer. One of the finest Occidental Planes I am acquainted with stands in my own garden at Vicar's Hill; where its boughs, feathering to the ground, form a canopy of above fifty feet in diameter."
The Occidental Plane is propagated by cuttings, which will hardly fail to succeed if they are taken from strong young wood, and are planted early in the autumn in a moist good mould.