Often cultivated as an ornamental tree in western and central Europe, where it grows rapidly and promises to attain a large size; hardy and occasionally planted in the New England and middle Atlantic states. 10. THUJA L. Arbor-vitæ. Resinous aromatic trees, with thin scaly bark, soft durable straight-grained heartwood, thin nearly white sapwood, slender spreading or erect branches, pyramidal heads, flattened lateral pendulous branchlets disposed in one horizontal plane, forming a flat frond-like spray and often finally deciduous, and naked buds. Leaves decussate, scale-like, acute, stomatiferous on the back, on leading shoots appressed or spreading, rounded or slightly keeled on the back, narrowed into long slender points, on lateral branchlets much compressed in the lateral ranks, prominently keeled and nearly covering those of the other ranks; on seedling plants linear-lanceolate, acuminate, spreading or reflexed. Flowers minute, monœcious, from buds formed the previous autumn, terminal, solitary, the two sexes usually on different branchlets; male ovoid, with 4—6 decussate filaments, enlarged into suborbicular peltate connectives bearing on their inner face 2—4 subglobose anther-cells; female oblong, with 8—12 oblong acute scales opposite in pairs, the ovuliferous scales at their base bearing usually 2 erect bottle-shaped ovules. Fruit an ovoid-oblong erect pale cinnamon-brown cone maturing in one season, its scales thin (thick in one species), leathery, oblong, acute, marked near the apex by the thickened free border of the enlarged flower-scales, those of the 2 or 3 middle ranks largest and fertile. Seeds usually 2, erect on the base of the scale, ovoid, acute, compressed, light chestnut-brown; seed-coat membranaceous, produced except in one species into broad lateral wings distinct at the apex; cotyledons 2, longer than the superior radicle. Thuja is confined to northeastern and northwestern America, to Japan, Korea and northern China. Five species are recognized. Of the exotic species the Chinese _Thuja orientalis_, L., with many varieties produced by cultivation, is frequently planted in the United States, especially in the south and west, for the decoration of gardens, and is distinguished from the other species by the thick umbonate scales of the cone, only the 4 lower scales being fertile, and by the thick rounded dark red-purple seeds without wings. _Thuja_ is the classical name of some coniferous tree. CONSPECTUS OF THE NORTH AMERICAN SPECIES. Fruit with usually 4 fertile scales. 1. T. occidentalis (A). Fruit with usually 6 fertile scales. 2. T. plicata (B, F, G). 1. Thuja occidentalis L. White Cedar. Arbor-vitæ. [Illustration: Fig. 66]