The Fir, the Pine, and the Larch, says Baxter, constitute a perfectly natural demus or family, and, next to the Oak, are the most valuable of our timber trees; but independent of their nature in this respect, their beautiful foliage and magnificent appearance have at times rendered them objects of admiration and attention "Of the four natural tribes into which the firs resolve themselves, the Silver Fir may be taken as the true representative of the first, the Norway Spruce of the second, the Larch the third, the Cedar the fourth".

All the firs are lofty trees, and are remarkable for the regularity and symmetry of their pyramidal heads. The leaves are solitary, needle-shaped, and rigid. They are distinguished from the other pines by the smoothness of their bark, in which are formed cavities containing their peculiar balsam, by the silvery whiteness of the under surface of the seemingly two-rowed leaves, and by their long, exact cones, formed of woody, deciduous scales, with a smooth thin edge.