Species of ornamental and timber evergreen conifer of the cypress family, native to eastern North America, growing to 20 m (65 feet) tall. It is the most common and probably the hardiest of the arborvitae. Its trunk is sometimes forked near the ground into several main stems covered with reddish brown bark. The cones have 8 to 10 scales, of which only four are usually fertile. Most cultivated varieties are narrow, densely pyramidal shrubs, and many have interesting variations in foliage color.