Evergreen trees or shrubs with flattened sprays, the leaves very small, scale-like, appressed, overlapping each other, opposite, 4-ranked. Cones ovoid or oblong, mostly spreading, the 6-10 scales opposite, dry, spreading when mature.

Fig. 19. Thuja occidentalis

Fig. 19. Thuja occidentalis.

1. T. occidentalis L. Arborvitae. A conical tree 10-35 m. high, 3-6 dm. in diameter, with pale shreddy bark and light, soft, but durable wood; leaves 2-3 mm. broad, of two sorts, the two lateral rows keeled, the two other rows flat, causing the twig to appear much flattened; cones oblong, 8-12 mm. long, reddish-brown, maturing in early autumn,persisting through the following winter; seeds broadly winged all around. Swamps and rocky banks, Quebec to Saskatchewan, south chiefly on limestone outcrops to Minnesota, Ohio, and the mountains of North Carolina and Tennessee (Fig. 19).