Introduction to Thuja: National third-level protected plant. Small evergreen tree, up to 10 meters tall, with a diameter at breast height of 10-30 cm; the bark of young trees is reddish-brown, smooth, and that of older trees is gray-brown, with strips and longitudinal fissures; branches are flat or slightly drooping; branchlets are alternate and young. Green, flat, arranged on one side, with 3-4 epiphyseal branches red and streaked with sandy reddish brown.