Fir

The firs (Abies) form a plant genus in the pine family (Pinaceae). All fir species are evergreen deep-rooted trees with a straight, columnar trunk. The conical crown is formed of regular tiers of relatively short, horizontal branches. Most species are forest trees in their habitat and are then often among the largest forest tree species.

A tree is generally understood to be a woody plant consisting of a root, a tall trunk rising from it, and a leafy crown. Botany defines trees as perennial and woody seed plants that have a dominant shoot axis that increases in girth through secondary growth of thickness.

These characteristics distinguish a tree from shrubs, ferns, palms, and other woody plants. In contrast to their developmental predecessors, most trees also have much more differentiated leaf organs that arise from multiple branched lateral shoots (long and short shoots). The trunk, branches and twigs elongate every year through the sprouting of terminal and lateral buds, becoming lignified in the process and continuously increasing in girth. In contrast to shrubs, it is a special characteristic of trees that the terminal buds dominate over the lateral buds (apical dominance) and thus a predominant main shoot develops (acrotonia).