This unrivaled forest is still further enriched by two majestic silver firs, Abies magnifica and Abies concolor, bands of which come down from the main fir belt by cool shady ridges and glens. Abies magnifica is the noblest of its race, growing on moraines, at an elevation of seven thousand to eight thousand five hundred feet above the sea, to a height of two hundred or two hundred and fifty feet, and five to seven in diameter; and with these noble dimensions there is a richness and symmetry and perfection of finish not to be found in any other tree in the Sierra. The branches are whorled, in fives mostly, and stand out from the straight red purple bole in level or, on old trees, in drooping collars, every branch regularly pinnated like fern fronds, and clad with silvery needles, making broad plumes singularly rich and sumptuous.
The flowers are in their prime about the middle of June: the staminate red, growing on the underside of the branchlets in crowded profusion, giving a rich color to nearly all the tree; the pistillate greenish yellow tinged with pink, standing erect on the upper side of the topmost branches; while the tufts of young leaves, about as brightly colored as those of the Douglas spruce, push out their fragrant brown buds a few weeks later, making another grand show.
The cones mature in a single season from the flowers. When full grown they are about six to eight inches long, three or four in diameter, blunt, massive, cylindrical, greenish gray in color, covered with a fine silvery down, and beaded with transparent balsam, very rich and precious-looking, standing erect like casks on the topmost branches. If possible, the inside of the cone is still more beautiful. The scales and bracts are tinged with red, and the seed wings are purple with bright iridescence.
Abies concolor, the white silver fir, grows best about two thousand feet lower than the magnifica. It is nearly as large, but the branches are less regularly pinnated and whorled, the leaves are longer, and instead of standing out around the branchlets or turning up and clasping them they are mostly arranged in two horizontal or ascending rows, and the cones are less than half as large. The bark of the magnifica is reddish purple and closely furrowed, that of the concolor is gray and widely furrowed,—a noble pair, rivaled only by the Abies grandis, amabilis, and nobilis of the forests of Oregon, Washington, and the Northern California Coast Range. But none of these northern species form pure forests that in extent and beauty approach those of the Sierra.
The seeds of the conifers are curiously formed and colored, white, brown, purple, plain or spotted like birds eggs, and expecting the juniper they are all handsomely and ingeniously winged with reference to their distribution. They are a sort of cunningly devised flying machines,—one-winged birds, birds with but one feather,—and they take but one flight, all save those which, after flying from the cone-nest in calm weather, chance to alight on branches where they have to wait for a wind. And though these seed wings are intended for only a moment's use, they are as thoughtfully colored and fashioned as the wings of birds, and require from one to two seasons to grow. Those of the pine, fir, hemlock, and spruce are curved in such manner that, in being dragged through the air by the seeds, they are made to revolve, whirling the seeds in a close spiral, and sustaining them long enough to allow the winds to carry them to considerable distances,—a style of flying full of quick merry motion, strikingly contrasted to the sober dignified sailing of seeds on tufts of feathery pappus. Surely no merrier adventurers ever set out to seek their fortunes. Only in the fir woods are large flocks seen; for, unlike the cones of the pine, spruce, hemlock, etc., which let the seeds escape slowly, one or two at a time, by spreading the scales, the fir cones when ripe fall to pieces, and let nearly all go at once in favorable weather. All along the Sierra for hundreds of miles, on dry breezy autumn days, the sunny spaces in the woods among the colossal spires are in a whirl with these shining purplewinged wanderers, notwithstanding the harvesting squirrels have been working at the top of their speed for weeks trying to cut off every cone before the seeds were ready to swarm and fly. Sequoia seeds have flat wings, and glint and glance in their flight like a boy's kite. The dispersal of juniper seeds is effected by the plum and cherry plan of hiring birds at the cost of their board, and thus obtaining the use of a pair of extra good wings.