The genus name is derived from the Latin "to rise" in reference to the height of its species.[4] The common English name originates with the Old Norse, fyri, or the Old Danish, fyr.[5]
They are large trees, reaching heights of 10–80 metres (33–262 feet) tall with trunk diameters of 0.5–4 m (1 ft 8 in – 13 ft 1 in) when mature. Firs 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 base resembling a suction cup, and by their cones, which, like those of true cedars, stand upright on the branches like candles and disintegrate at maturity.
Identification of the different species is based on the size and arrangement of the leaves, the size and shape of the cones, and whether the bract scales of the cones are long and exserted, or short and hidden inside the cone.
Description
Leaves
A. alba – the underside of leaves have two whitish strips formed by wax-covered stomatal bands; the bases of the needles are shaped like suction cups.
Firs can be distinguished from other members of the pine family by the unique attachment of their needle-like leaves to the twig by a base that resembles a small suction cup.
The leaves are significantly flattened, sometimes even looking like they are pressed, as in A. sibirica.
The leaves have two whitish lines on the bottom, each of which is formed by wax-covered stomatal bands. In most species, the upper surface of the leaves is uniformly green and shiny, without stomata or with a few on the tip, visible as whitish spots. Other species have the upper surface of leaves dull, gray-green or bluish-gray to silvery (glaucous), coated by wax with variable number of stomatal bands, and not always continuous. An example species with shiny green leaves is A. alba, and an example species with dull waxy leaves is A. concolor.
The way they spread from the shoot is very diverse, only in some species comb-shaped, with the leaves arranged on two sides, flat (A. alba) [6][clarification needed]
The upper foliage is different on cone-bearing branches, with the leaves short, curved, and sharp.[7]
Abies produce a variety of terpenoids. The analyses of the Zavarin group – from Smedman et al 1969 to Zavarin et al 1977 – showed variation in terpenoid composition of the bark by genetics, geography, age and size of the tree.[8][9]
Classification
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.[10]
Section Grandis is found in western North America to Mexico, Guatemala, Honduras and El Salvador, in lowlands in the north, moderate altitudes in south.
Wood of most firs is considered unsuitable for general timber use and is often used as pulp or for the manufacture of plywood and rough timber. It is commonly used in Canadian Lumber Standard graded wood.[15] Because this genus has no insect or decay resistance qualities after logging, it is generally recommended in construction purposes for indoor use only (e.g. indoor drywall on framing). Firwood left outside cannot be expected to last more than 12 to 18 months, depending on the type of climate it is exposed to.
Nordmann fir, noble fir, Fraser fir and balsam fir are popular Christmas trees, generally considered to be the best for this purpose, with aromatic foliage that does not shed many needles on drying out. Many are also decorative garden trees, notably Korean fir and Fraser fir, which produce brightly coloured cones even when very young, still only 1–2 m (3 ft 3 in – 6 ft 7 in) tall. Other firs can grow anywhere between 30 and 236 feet (9.1 and 71.9 m) tall. Many fir species are grown in botanic gardens and other specialist tree collections in Europe and North America.[16] Fir Tree Appreciation Day is June 18.
^ abSchorn, Howard; Wehr, Wesley (1986). "Abies milleri, sp. nov., from the Middle Eocene Klondike Mountain Formation, Republic, Ferry County, Washington". Burke Museum Contributions in Anthropology and Natural History. 1: 1–7.
^Debreczy Zsolt Rácz István and Kathy Musial. 2011. Conifers Around the World : Conifers of the Temperate Zones and Adjacent Regions. Budapest: DendroPress.
^ abSeneta, Włodzimierz (1981). Drzewa i krzewy iglaste (Coniferous trees and shrubs) (in Polish) (1st ed.). Warsaw: Państwowe Wydawnictwo Naukowe (PWN). ISBN978-83-01-01663-0.
^Hemingway, R. W. (2018-01-18). "Bark: Its Chemistry and Prospects for Chemical Utilization". Organic Chemicals from Biomass. CRC Press. pp. 189–248. ISBN978-1-351-07525-1.
^Barton, George M. (2018-01-18). "Foliage". Organic Chemicals from Biomass. CRC Press. pp. 249–280. ISBN978-1-351-07525-1.
^Knowlton, F.H. (1923). Fossil plants from the Tertiary lake beds of South-Сentral Colorado (Report). Professional Paper. Vol. 131-G. United States Geological Survey. pp. 183–197. doi:10.3133/pp131G.
^Wolfe, J.A.; Schorn, H.E. (1990). Taxonomic revision of the Spermatopsida of the Oligocene Creede flora, southern Colorado (Report). Bulletin. Vol. 1923. United States Geological Survey. pp. 1–40. doi:10.3133/b1923.