This order formerly included the Plane trees and the Liquidambar; but many botanists now put the latter tree in a separate order, which they call Balsamaceæ.
THE GENUS PLATANUS.
In the Oriental Plane (Platanus orientalis) the male and female flowers are both in globular catkins. The male flowers are composed of very small, but rather fleshy bracts, which remain on after the stamens fall; and the female flowers are each furnished with bracts, and have two long stigmas. Both kinds of flowers are so small as not to be seen without a microscope. The fruit is covered with fine hair. The globular catkins retain the bracts, and these remain on after the seed has fallen, giving the tree a very singular appearance even in winter. The Occidental Plane (P. occidentalis) differs principally from the preceding species in the leaves being more downy beneath; the buds are also so downy that the tree in America is called the Cotton-tree. Both kinds are remarkable for the manner in which the bark becomes detached from the main trunk and peels off.
THE GENUS LIQUIDAMBAR.
The common Liquidambar (L. styraciflua) is remarkable for the beautiful crimson which its maple-like leaves take in autumn. The male flowers are on an upright catkin, and the female ones in a globular one, like the Planes. When the fruit is ripe, the numerous capsules that surround the globular catkin burst, and the seeds, which are winged, are scattered by the wind.
THE ORDER MYRICACEÆ.
The principal genera are Myrica, the Sweet Gale; Comptonia, a curious shrub with fern like leaves; and Casuarineæ, a New Holland tree without leaves, but with jointed leaf-like stems.
THE GENUS MYRICA.
The male flowers are produced in rather long erect catkins, each having only one scale, and four stamens. The female catkins are short, and each flower has three scales or bracts; the ovary has two long stigmas, and the fruit is a drupe, the scales becoming fleshy when ripe. The bracts and leaves are covered with glands filled with aromatic oil; and in M. cerifera, the fruit is covered with a waxy secretion, which is used as wax.