Fir

Firs are evergreen coniferous trees belonging to the genus Abies (Latin: [ˈabieːs]) in the family Pinaceae. There are approximately 48–65 extant species, found on mountains throughout much of North and Central America, Eurasia, and North Africa. The genus is most closely related to Keteleeria, a small genus confined to eastern Asia.

They are tall trees that can be distinguished from other members of the pine family by the way in which their needle-like leaves are attached singly to the branches with a circular base, and by their cones, which, like those of cedars, stand upright on the branches like candles and disintegrate at maturity.

The wood of firs is used for pulp to make paper, for plywood, and for indoor construction. Some species serve as Christmas trees, while others are used as decorative trees with their brightly coloured cones. In art, Lucas Cranach the Elder painted Madonna under the fir tree for Wrocław Cathedral in 1510.

The English name "fir" derives from the Old Norse fyri or the Old Danish fyr. The generic name Abies is the Latin for "fir".

Fir trees are tall, often 40–60 metres and sometimes approaching 100 metres high, usually with a single straight trunk. The crown starts conical, but becomes more varied in shape with age. The primary branches are arranged in whorls around the trunk.

Firs have needle-like leaves, arranged spirally but often appearing to be in two or more rows on opposite sides of the twigs. The base of each leaf is round and attached to a small pit in the twig. Each leaf is normally twisted at its base so that the side with stomata faces downwards. In the upper crown on cone-bearing branches, the leaves are shorter, curved, and sometimes sharp.

Firs differ from other conifers such as spruces in having erect, cylindrical female seed cones 5–25 cm (2–10 in) long that disintegrate at maturity to release the winged seeds. Seed cones take a year to become mature; they start out green or other bright colour, darkening as they develop to dark brown or black. The leaflike seed bracts are visible when young, and in some species remain so. The seeds sit in thin cups; each seed has a triangle-shaped wing. The male cones are pendulous (dangling) and resemble catkins; both pollen and seeds are wind-dispersed.

The oldest pollen assignable to the genus dates to the Late Cretaceous in Siberia, with records of leaves and reproductive organs across the Northern Hemisphere from the Eocene onwards.