Nat. Ord. (Natural Order) Xanthoxylaceï¿½. Lin. Syst. (Linnean System) Polygamia, Monï¿½cia. Ailanto is the name of this tree in the Moluccas, and is said to signify Tree of Heaven; an appellation probably bestowed on account of the rapidity of its growth, and the great height which it reaches in the East Indies, its native country. When quite young it is not unlike a sumac in appearance; but the extreme rapidity of its growth and the great size of its pinnated leaves, four or five feet long, soon distinguish it from that shrub. During the first half dozen years it outstrips almost any other deciduous tree in vigor of growth, and we have measured leading stems which had grown twelve or fifteen feet in a single season. In four or five years, therefore, it forms quite a bulky head, but after that period it advances more slowly, and in 20 years would probably be overtopped by the poplar, the plane, or any other fast growing tree. There are, as yet, no specimens in this country more than 70 feet high; but the trunk shoots up in a fine column, and the head is massy and irregular in outline. In this country it is planted purely for ornament, but we learn that in Europe its wood has been applied to cabinet work; for which, from its close grain and bright satin-like lustre, it is well adapted* (* Annales de la Societe d'Horticulture.). The male and female flowers are borne on separate trees, and both sexes are now common, especially in New York. The male forms the finer ornamental tree, the female being rather low, and spreading in its head.