On the mountains the trees are chiefly pines, firs, spruce and hemlock.
Thus, the cones of firs and the stroboli of the hop are composed of a series of spirally arranged bracts covering fertile flowers; and the scales on the fruit of the pine-apple are of the same nature.
Above this belt of mahogany, pines and firs are sometimes found.
Oaks, elms, firs, ashes and beeches are the principal forest trees.
The best known and by far the largest division of the Gymnosperms is that of the cone-bearing trees (pines, firs, cedars, larches, &c.), which play a prominent part in the vegetation of the present day, especially in the higher latitudes of the northern hemisphere; certain members of this class are of considerable antiquity, but the conifers as a whole are still vigorous and show but little sign of decadence.