PLANE  . 1 . In

botany, the common name of a handsome tree known botanically as Platanus orientalis, a native of Greece and western Asia, a favourite shade-tree of the ancient Greeks and Romans, and introduced by the latter to south-west Europe . It Plane (Platanus orientalis) . 1, Leaf, nat. size . 2 and 3, Base of leaf-stalk showing bud-protecting cap, about i nat. size . 4, Male, 5, Female inflorescence . 6, Head of fruits, about i nat. size . 7, A fruit with enclosed seed, cut lengthwise . is one of the most successful trees in London and other large towns; the smooth face of the leaf is easily washed by rain; and the periodical peeling of the bark also serves to get rid of impurities . It is a large tree with widely spreading branches and alternate, palmately five-lobed leaves, resembling those of the sycamore in shape, but quite hairless and of a brighter green . The bud in the leaf axil is protected during its development by the hollow base of the leaf-stalk, which lifts off like an extinguisher when the leaf falls in autumn .

The

minute, unisexual flowers are borne in dense pendulous heads, which contain either male or female flowers; the small one-seeded fruits are densely crowded in a ball, from which they gradually separate in drying, and are readily carried by the wind . The wood, which is hard and heavy, though not strong, is used in Persia and other countries of western Asia for house construction and furniture . A variety of forms are known in cultivation, the commonest being the maple-leaved (acerifolia), the London plane, which has usually three-lobed leaves; var. laciniata has very deeply much divided leaves, and var. variegata, variegated foliage . Platanus occidentalis, an allied species, is a native of the United States, being most abundant and growing to its largest size in the bottom lands of the basins of the lower Ohio and the Mississippi rivers . It was introduced into England early in the 17th century, and is occasionally met with in western and central Europe . Professor C . S . Sargent (Silva of North America) refers to it as the most massive if not the tallest, deciduous-leaved tree of the North American forest; it is known in America as sycamore and buttonwood . It differs from P. orientalis in its less deeply lobed, more leathery pubescent leaves and in the usually solitary balls of fruit . 2 . The name of a carpenter's hand-tool, used for levelling and smoothing (Lat. planus, level) the surface of wood . The machine tool used for a similar purpose for metals is generally known as a planing-machine or planer .