The Austrian pine (Pinus Austriaca).—Leaves in clusters of two, five or six inches long and somewhat rigid, dark green in color, and persisting for four or five years; cones about three inches long, conical in shape; and scales not beaked or pointed as in the Scotch pine.
The Norway spruce (Picea excelsa).—Leaves borne singly, about one inch long, dark green, four-sided; cones about six inches long, and composed of thin scales, and usually borne on the tips of branchlets. The small branches mostly drooping.
The black spruce (Picea nigra).—In general appearance, this is not very unlike the Norway spruce, but the small branches stand out more horizontally and the cones are only one or one and one-half inches long, recurving on short branches. The cones persist for several years after shedding the seed.
The white spruce (Picea alba).—Leaves about one inch long, having a glaucous or whitish tinge; twigs stout and rigid, of a pale greenish-white color; cones from one to two and one-half inches long, more or less cylindrical or "finger-shaped," and easily crushed when dry.
The red spruce (Picea rubra).—The foliage lacks the whitish tinge of the white spruce and is of a dark or dark yellowish color; twigs stouter than those of the black spruce and not so much inclined to droop; cones about one inch long, obovate, and usually falling by the second summer.
The hemlock (Tsuga Canadensis).—Leaves about one-half inch long, flat with rounded point, green on the upper side, whitish beneath, and borne on short appressed petioles; cones about three-quarters of an inch long, oval or egg-shaped, and borne on the ends of small branchlets and often persisting for some time.
The balsam fir (Abies balsamea).—Leaves narrow, less than one inch long, borne singly, very numerous and standing out from the branchlets in much the way of the spruce; cones about three inches long, cylindrical, composed of thin scales, and standing upright on the branches, or recurved; bark smooth, light green with whitish tinge.
The arbor-vitæ (Thuya occidentalis).—Leaves very small, scale-like, and over-lapping one another in four rows, adhering closely to the branchlets; the cones oblong and small,—a half-inch or less in length,—and composed of but few scales.