Firs (Abies)

Key to North America Species of Abies Individual North American Species Accounts Abies amabilis Pacific Silver Fir Abies balsamea Balsam Fir Abies bracteata Bristle-cone Fir Abies concolor White fir Abies fraseri Fraser's Fir Abies grandis Grand Fir Abies lasiocarpa Subalpine Fir Abies magnifica California Red Fir Abies procera Noble Fir

FIRS (ABIES) The true firs are evergreen, monoecious (both sexes found in the same individual) trees. The trees are commonly tall, thin, and conical although the top may become flattened in older individuals. Firs near the tree line of the subalpine zones of montains are commonly stunted or twisted. The cones of firs are distinctive, occur upright on the branches, and are usually found near the tops of the trees. The cones fall apart on maturity leaving a central core. The genus Abies is found in the temperate and boreal regions of the Northern Hemisphere. There are about 50 species worldwide, although many of the species are closely related and species limits are not completely understood. Almost all of the species, except for two boreal species, are found in montane regions, sometimes very near timberline. There are 9 species of Abies recognized in North America. True Firs are used for both lumber and wood pulp, and are also commonly farmed for Christmas trees.   Identification Features:   Female cones upright on branches (a), usually clustered near the top of the tree. Female cones disintegrating on maturity commonly leaving a central core (b).   Needle scars large, round, and depressed (concave); needles lack a thin neck (petiole) at the base.