Fir

"Fir Tree" redirects here. For the County Durham town, see Fir Tree, County Durham.
Firs
Temporal range: 49–0Ma

[1]

Korean fir (Abies koreana) cone and foliage
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Pinaceae
Genus: Abies
Mill.
Species

See text

Firs (Abies) are a genus of 48–55 species of evergreen coniferous trees in the family Pinaceae. They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range. Firs are most closely related to the genus Cedrus (cedar). Douglas firs are not true firs, being of the genus Pseudotsuga.

They are large trees, reaching heights of 10–80 m (33–262 ft) tall and 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 unique attachment of their needle-like leaves and by their different cones.

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.

Leaves

A. alba - the underside of leaves with 2 whitish strips formed by wax-covered stomatal bands
A. grandis foliage - upper side of the leaves
Atypical A. alba foliage from Dinaric calcareous fir forests on Mt. Orjen

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 strips on the bottom, each of which is formed by wax-covered stomatal bands. The upper surface of the leaves usually is uniformly green and shiny, without stomata or only with few at their tips, visible as whitish spots. Some of the species however have the upper surface of leaves dull, gray-green, bluish-gray to silvery, 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 tips of leaves are usually more or less notched (as in A. firma), but sometimes rounded or dull (as in A. concolor, A. magnifica) or sharp and prickly (as in A. bracteata, A. cephalonica, A. holophylla). The leaves of young plants are usually sharper.

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) [2]

Cones

Intact and disintegrated Bulgarian fir cones
Immature cones of some of species or races are green, not purple-bluish. Manchurian fir.
Disintegrating cones of Manchurian fir

Firs differ from other conifers in having erect, cylindrical cones 5–25 cm (2.0–9.8 in) long that disintegrate at maturity to release the winged seeds.

In contrast to spruces, even large fir cones do not hang, but are raised like candles.

Mature cones are usually brown, young in summer can be green, for example:

A. grandis, A. holophylla, A. nordmanniana

or purple and blue, sometimes very dark:

A. fraseri, A. homolepis (var. umbellata green), A. koreana ('Flava' green), A. lasiocarpa, A. nephrolepis (f. chlorocarpa green), A. sibirica, A. veitchii (var. olivacea green). [2]

Classification

A. fabri, Sichuan, China
A. magnifica, California, USA

Uses and ecology

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. Because this genus has no insect or decay resistance qualities after logging, it is generally recommended for construction purposes as indoor use only (e.g. indoor drywall on framing). This wood left outside cannot be expected to last more than 12 to 18 months, depending on the type of climate it is exposed to. It is commonly referred to by several different names, including North American timber, SPF (spruce, pine, fir) and whitewood.

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 (3.3–6.6 ft) tall. Other firs can grow anywhere between 30 and 236 feet (9.1 and 71.9 m) tall. Fir Tree Appreciation Day is June 18.

Firs are used as food plants by the caterpillars of some Lepidoptera species, including Chionodes abella (recorded on white fir), autumnal moth, conifer swift (a pest of balsam fir), the engrailed, grey pug, mottled umber, pine beauty and the tortrix moths Cydia illutana (whose caterpillars are recorded to feed on European silver fir cone scales) and C. duplicana (on European silver fir bark around injuries or canker).

Abies spectabilis or Talispatra is used in Ayurveda as an antitussive drug.

References

  1. 1.0 1.1 Schorn, 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.
  2. 2.0 2.1 Seneta, Włodzimierz (1981). Drzewa i krzewy iglaste (Coniferous trees and shrubs) (in Polish) (1st ed.). Warsaw: Państwowe Wydawnictwo Naukowe (PWN). ISBN 83-01-01663-9.

Bibliography

Philips, Roger. Trees of North America and Europe, Random House, Inc., New York ISBN 0-394-50259-0, 1979.

External links

Wikimedia Commons has media related to Abies.

[1]

  1. Platt, Karen "Gold Fever" provides descriptions of golden or yellow-leaved Abies cultivars http://www.karenplatt.co.uk