AR'BOR VI/TIE (Let., tree of life), Thuja. A genus of plants of the order Coni fers, allied to the cypress, and consisting of evergreen trees and shrubs with compressed or flattened bra nchlets—small, scale-like, imbricated leaves. Species of arbor vita are found in the north temperate zones of both hemispheres. The common arbor vita (Thu ja occidentalis) is a native of North America, especially between latitude 45° and latitude 45°, but has long been well known in Europe. It is a tree forty to fifty feet high; its branches are horizontally ex panded, and the strobiles (cones) small and obovate. The young leafy twigs have a balsamic smell, and both they and the wood were for merly in great repute as a medicine: the oil obtained by distillation from the twigs, which has a pungent and camphor-like taste, lies been recommended as a vermifuge. The wood of the stem is reddish, soft, and very light, but com pact, tough, and durable, bearing exposure to the weather remarkably well. The tree is com mon in Great Britain, planted chiefly as an ornament. It seldom attains so great a size as in its native country. It flourishes in cool, moist localities. The Chinese arbor vita, Thuja oricntalis, a native of China and Japan, which is immediately distinguishable from the former species by its upright branches and larger, al most globose and rough strobiles, is also, in Great Britain and upon the continent of Europe, a common ornament of pleasure grounds; but it does not attain so great a size as the preced ing, and is more sensible of the cold of severe winters. The balsamic smell is very agree
able. The tree yields a resin with a pleasant odor. to which medicinal virtues were once ascribed; hence the name, arbor vita', given to this species and extended to the genus. There are several other species of Thuja, sonic of which seem well suited to the open air in the climate of Great Britain, and others require the protec tion of Among the former are Thu ja plicata. California to Alaska. and Thuja dolabrata. a native of Japan, a tree of great height and thickness, which will not im probably prove one of the most important of the whole genus. In favorable forest con ditions both Thula oecidentalis and Thuja plieata become rather large trees, the timber of which is very valuable. There are about sixty horticultural varieties of the American species, that vary in habit of growth, color of foliage, or other characteristics. Many of these are popular in landscape gardening. A tree com mon in North America and there known by the name of White Cedar is sometimes included in the geniis Thuja, under the name of Thuja splu•roitica, but is more generally ranked in the genus Cupressns as Cupressus thyoides. See CYPRESS. Closely allied to the genus Thula. is CanitriS. See SANDARAC.