Cone Bearing Evergreens - Firs
( Originally Published 1927 )
In a forest of evergreens the spire form, needle leaves, and some other traits belong to several families. To distinguish the firs from the spruces, which they closely resemble in form and foliage, notice the position of the cones. All fir trees hold their ripe cones erect. No other family with large cones has this striking characteristic. All the rest of the conifers have pendent cones, except the small-fruited cypresses and arbor-vitaes.
All fir trees belong to the genus abies, whose twenty-five species are distributed from the Far North to the highlands of tropical regions in both the Eastern and Western Hemispheres. All are tall pyramidal trees, with wide-spreading horizontal limbs bearing thick foliage masses, and with bark that contains vesicles full of resinous balsam. The branches grow in whorls and spread like fern fronds, covered for eight or nine years with the persistent leaves. Circular scars are left on the smooth branches when they fall.
The leaves are the distinguishing character of the genus when cones are lacking. They are usually flat, two-ranked on the twig, without stems, and blunt, or even notched at the tip. For these typical leaves one must look on the lower sterile branches of the tree, and back of the growing shoots, where leaves are apt to be crowded and immature. The cones are borne near the tops of the trees, and on these branches the leaves are often crowded and not two-ranked as they are below. The flowers of fir trees are abundant and showy, the staminate clusters appearing on the under sides of the platforms of foliage; the pistillate held erect on platforms higher up on the tree's spire. Al-ways the flowers are borne on the shoots of the previous season. The cone fruits are cylindrical or ovoid, ripening in a single season and discharging their seeds at maturity. The stout tapering axis of the cone persists after seeds and scales have fallen.
The bark of fir trees is thin, smooth, and pale, with abundant resin vesicles, until the trees are well grown. As age advances the bark thickens and becomes deeply fur-rowed. The wood is generally pale, coarse-grained, and brittle.
The Balsam Fir
Ab´es balsamea, Mill.
The balsam fir is probably best known as the typical Christmas tree of the Northeastern states and the source of Canada balsam, used in laboratories and in medicine. Fresh leaves stuff the balsam pillows of summer visitors to the North Woods. In the lumber trade and in horticulture this fir tree cuts a sorry figure, for its wood is weak, coarse, and not durable, and in cultivation it is short-lived, and early loses its lower limbs.
Throughout New England, northward to Labrador, and southward along the mountains to southwestern Virginia, this tree may be known at a glance by its two-ranked, pale-lined leaves, lustrous and dark green above, one half to one and one half inches long, sometimes notched on twigs near the top of the tree. Rich dark purple cones, two to four inches long, with thin plain-margined, broad scales, stand erect, glistening with drops of balsam, on branches near the top of the tree. The same balsam exudes from bruises in the smooth bark. By piercing the white blisters and systematically wounding branch and trunk, the limpid balsam is made to flow freely, and is collected as a commercial enterprise in some parts of Canada. "Oil of fir" also is obtained from the bark.
The Balsam Fir
A. Fraseri, Poir.
This balsam fir, much more luxuriant in foliage, and worthier of cultivation as an ornamental tree, is native to the Appalachian Mountains of southwestern Virginia, Tennessee and North Carolina. The purple cones are ornamented by pale yellow cut-toothed bracts that turn back over the edge of the plain scale. Limited in range, but forming forests between the limits of four and six thousand feet in altitude, this tree is confined to local uses as lumber and fuel.
All the other firs of America are Western, and among these are some of the tree giants of the world.
The Red Fir
A. magnifica, A. Murr.
The magnificent red fir is called by John Muir "the noblest of its race." In its splendid shaft that reaches two hundred and fifty feet in height, and a trunk diameter of seven feet, there is a symmetry and perfection of finish throughout that is achieved by no other tree. One above another in graduated lengths the branches spread in level collars, the oldest drooping on the ground, the rest horizontal, their framework always five main branches that carry luxuriant flat plumes of silvery needles. Each leaf is almost equally four-sided, ribbed above and below, with pale lines on all sides, so wide as to make the new growth silvery throughout the season. Later these leaves become blue-green, and persist for about ten years. Only on the lower side of the branch are the Ieaves two-ranked.
The bark of this fir tree is covered with dark brown scales, deeply divided into broad rounded ridges, broken by cross fissures when old. Out toward the tips of the branches the bark is silvery white. In mid-June the flowers appear, the staminate in profuse clusters against the silvery leaf-linings, bright red, on the under sides of the platforms. It is a blind or stupid person who can travel in fir woods and fail to notice this wonderful flower pageant, that may be viewed by merely looking upward. The pistillate flowers, greenish yellow, tipped with pink, are out of sight as a rule, among the needles in the tree-tops. They ripen into tall cylindrical cones, six to eight inches long and half as wide, that fall to pieces at maturity, discharging their broad thin scales with the purple irides-cent winged seeds.
Pure forests of this splendid fir tree are found in southern Oregon among the Cascade Mountains, between five and seven thousand feet above the sea. It is the commonest species in the forest belt of the Sierra Nevada, between elevations of six thousand and nine thousand feet. From northern California, it follows the western slope of the Sierra Nevada, climbing to ten thousand feet in its southernmost range. A variety, Shastensis, Lemm., is the red fir with bright yellow fringed bracts on its stout cones. This ornament upon its fruits seems to be the chief distinguishing character of the form which occurs with the parent species on the mountains in Oregon and northern California, and recurs in the southern Sierra Nevada.
The best defense of this superb red fir is the comparative worthlessness of its soft, weak wood. Coarse lumber for cheap buildings, packing cases and fuel makes the only demands upon it. In European parks it is successfully grown as an ornamental tree, and has proved hardy in eastern Massachusetts.
The Noble Fir
A. nobilis, Lindl.
The noble fir or red fir is another giant of the Northwest. On the western slopes of the Cascade Mountains of Washington and Oregon it reaches occasionally two hundred and fifty feet in height, differing from magnifica in being round-topped instead of pyramidal before maturity. Its red-brown wood, furrowed lark and the red staminate flowers justify its name. The twigs are red and velvety for four or five years. The leaves are deeply grooved above, rounded and obscurely ribbed on the lower surface, blue-green, often silvery through their first season, crowded and curved so that the tips point away from the end of the branch.
The oblong cylindrical cones, four to five inches long, are velvety, their scales covered by bracts, shaped and notched like a scallop shell, with a forward-pointing spine, exceeding the bract in length. Forests of this tree at elevations of twenty-five hundred to five thousand feet are found in Washington and northern Oregon, from which limited quantities of the brownish-red wood enter the lumber trade under the name of "larch."
The White Fir
A. grandis, Lindl.
The white fir is a striking figure, from its silvery lined, dark green foliage, its slender pyramidal form that reaches three hundred feet in height, and the vivid green of its mature cones that are destitute of ornament and slenderly cylindrical. From Vancouver Island southward to Mendocino County in California, this tree is common from the sea level to an elevation of four thousand feet. Eastward it extends into Idaho, climbing to seven thous-and feet, but choosing always moist soil in the neighbor-hood of streams. Various uses, woodenwares, packing cases, and fuel consume its soft, coarse wood to a limited extent. The delicate grace of its sweeping down-curving branches makes it one of the most beautiful of our Western firs. It grows rapidly, and is a favorite in European parks.
The White Fir
A. concolor, Lindl. and Gord.
This white fir is a giant of the Sierras, but a tree of medium height in the Rocky Mountains. Its leaves are often two to three inches long, very unusual for a fir tree, curving to an erect position, pale blue or silvery at first, becoming dull green at the end of two or three years.
On the California Sierras, this silver fir tree lifts its narrow spire two hundred and fifty feet toward the sky and waves great frondlike masses of foliage on pale gray branches. As a much smaller tree, it is found in the arid regions of the Great Basin and of southern New Mexico and Arizona, territory which no other fir tree invades. In gardens of Europe and of our Eastern states this is a favorite fir tree, often known as the "blue fir" and the "silver fir" from its pale bark and foliage, whose blue cast is not always permanent. Eastern nurseries obtain their best trees from seeds gathered in the Rocky Mountains.