AILANTHUS (more correctly ailantus, from ailanto, an Amboyna word probably meaning "Tree of the Gods," or "Tree of Heaven"), a genus of trees belonging to the natural order Simarubaceae. The best known species, A. glandulosa, Chinese sumach or tree of heaven, is a handsome, quick-growing tree with spreading branches and large compound leaves, resembling those of the ash, and bearing numerous pairs of long pointed leaflets. The small greenish flowers are borne on branched panicles; and the male ones are characterized by having a disgusting odour. The fruits are free in clusters, and each is drawn out into a long wing with the seed in the middle. The wood is fine grained and satiny. The tree, which is a native of China and Japan, was introduced into England in 1751 and is a favourite in parks and gardens. A silk spinning moth, the ailanthus moth (Bombyx or Philosamia cynthia), lives on its leaves, and yields a silk more durable and cheaper than mulberry silk, but inferior to it in fineness and gloss. This moth is common near many towns in the eastern United States; it is about 5 in. across, with angulated wings, and in colour olive brown, with white markings. Other species of ailanthus are: A. imberbifiora and A. punctata, important Australian timber-trees; and A. excelsa, common in India.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)