The Gymnosperm Database
Detail of an
shoot showing leaf structure (white dots are stomata) and leaf attachment to twig [C.J. Earle].
floating on the water. One strategy that many conifers use to defeat seed predators is to produce no cones in most years, with a superabundance produced occasionally during "mast years" [C.J. Earle, 2009.09.26].
Fir [English]; نراد [Arabic]; 冷杉属 [Chinese]; Tanne [German]; sapin [French]; abete [Italian]; モミ属 [Japanese]; Пихта [Russian]; abies [Spanish].
Linnaeus initially (1753) assigned all firs, spruces and pines to the genus
. Miller forthwith (1754) assigned firs to the genus
). Various authors have assigned it to ranks above the level of family: Order Abietales Koehne 1893; Family Abietaceae Bercht. et J. Presl 1820; Subfamily Abietoideae Rich. ex Sweet 1826; Tribe Abieteae Rich. ex Dumort. 1827; and Subtribe Abietinae Eichler 1887. The genus has lately been revised by Rushforth (1987), with a full review of previous classification schemes provided by Farjon and Rushforth (1989). The classification used here is almost verbatim from Farjon (2010). As such, there are 48 species. The infrageneric classification is as follows:
several traditionally accepted species have closely allied sibling species, e.g.,
A. balsamea-A. fraseri, A. bifolia-A. lasiocarpa
A. magnifica-A. procera
. Other species may be more distinct morphologically, but many of these still appear to have evolved in geographic isolation without strong reproductive barriers developing. Thus, when distributions of species overlap, introgression between the taxa is the rule; this may make it difficult to assign certain individuals to a species" (Hunt 1993). Although this opinion was formulated in regard to certain North American firs, it is exceptionally appropriate to the firs of southwest China, particularly those of subsection
. Accurate determination of taxonomic relationships between these species will likely require genetic studies.
Like most other genera of Pinaceae, species of
are typically monoecious evergreen trees with a spire-like or conic crown that often becomes flattened or rounded in old trees. Near the alpine treeline, trees may grow with reduced stature and a contorted growth form, often forming krummholz at the upper limits of tree growth. Their form differs from most genera of Pinaceae in its exceptional uniformity;
typically possess a single straight trunk with regularly spaced branch whorls produced at the rate of one whorl per year, so that it is sometimes possible to determine the age of a tree 50 years old simply by counting branch whorls. The branch pattern is also exceptionally regular, with a single terminal and two lateral shoots produced each year at the tip of most active branches. Thus,
displays a geometric regularity of form that is only a little less common in
, is rather unusual in
, and is not found in
Smooth and thin on young trees, bearing resin blisters, in age often thick and furrowed or flaking in plates. In most species the bark provides little protection against fire, although a few species are fire-tolerant.
Whorled, spreading, flattened into a horizontal plane, with irregular internodal branches occasionally produced by epicormic sprouting.
Short (spur) shoots are absent. Twigs may be grooved or smooth; prominent leaf scars, circular to broadly elliptic, flush with twig surface, are slightly depressed or slightly raised evenly all around.
Borne singly, persisting 5 or more years (maximum 53 years in
), spirally arranged but often proximally twisted so as to appear either 1-ranked (pointing up like toothbrush bristles) or 2-ranked, sessile, typically constricted and often twisted above the somewhat broadened base, sheath absent; linear-lanceolate, flat, with two white stomatal bands beneath, keeled below, rounded or notched at the apex, with two resin ducts. Since many species are early seral and form dense stands, there is often a conspicuous structural difference between shade foliage, just described, and sun foliage, growing near the top of the crown in full sunlight. Sun foliage is more or less erect, incurved to nearly falcate, thickened or quadrangular. When identifying species, reference is made to mature shade foliage, unless otherwise noted. Buds are ovate or oblong with a rounded or pointed apex; terminal buds are surrounded by 4-5 secondary buds. Cotyledons 4-10.
Borne on year-old twigs, maturing in 1 season, erect, ovoid to cylindric, generally resinous, dehiscent (falling apart on maturity), cone axis persisting as an erect 'spike' on branch.
Lacking apophysis and umbo, rounded with a hidden or sometime protruding lobed bract (esp. see
Axillary, densely clustered along undersides of current year's twigs, globular or conic, appearing in the spring, pendant, yellow to red, green, blue, or purple, leaving gall-like protuberances after falling.
Winged, with a resin sac at the wing-seed juncture.
Lacks resin ducts.
Sources: Li (1975), Silba (1986), Rushforth (1987).
=12 (Hunt 1993).
"Notes on the following features, made at the time of collection of specimens, are useful in identification.
"Size and placement of resin canals in the leaves as seen in cross section with a hand lens when a leaf is pulled apart or cut with a sharp knife.
"Stance of the leaves, e.g., whether they are in flat sprays ('2-ranked') or point up like brush bristles ('1-ranked'), and whether some on a twig point in a direction different from others on the same twig.
"Differences in color and glaucousness of the lower and upper leaf surfaces.
"Shape of leaf apex as observed with a hand lens.
"Distribution of stomates - and number of rows of stomates - on the abaxial and adaxial leaf surfaces, particularly midway between base and apex of leaf.
"Leaf-scar periderm color. Pull a leaf from a twig and note, with a hand lens, the color of the scar's periphery.
"Presence or absence of resin on the buds (collect a few extra buds for dissection). If buds are not available (as in the early part of the growing season), collect older branch material bearing old bud scales.
"Cone color of both pollen and seed cones (binoculars are handy to note this feature of the seed cones)" (Hunt 1993).
Distribution and Ecology
N America, C America, Europe, N Africa, Asia (S to Himalaya, S China, and Taiwan), i.e., temperate and boreal regions of the northern hemisphere, chiefly in mountainous regions (Li 1975). Excepting the two boreal species,
(in North America) and
(in Eurasia), the genus is confined to mountainous areas in the subtropical and temperate latitudes of the northern hemisphere. Within this realm, its distribution is confined largely according to its ecological requirements and its paleobotanical history.
For information on ecological requirements, paleobotany and modern distribution, see Farjon (1990).
The greatest diameter and stem volume are found in
, though greater heights have been reported in
. The record trees for both species are found in Washington State, in the northwest United States.
. Again, found in Washington State, though comparably old trees probably occur in Canada: British Columbia.
tend to occur on sites with ample moisture and deep soils, where they grow quickly and do not attain great ages. Such conditions characterize closed forest situations, where competition between individuals tends to obscure the effect of large-scale factors, such as climate, on tree growth. Moreover, the tree rings are often difficult to discern and the wood decays quickly after tree death. Consequently,
has received relatively little attention in comparison with, say,
. What work has been done, has largely focused on ecological problems such as stand age structure and forest regeneration after disturbance.
"North American firs are cut for pulpwood and lumber and, largely from plantations, for Christmas trees. They are also grown as ornamentals. Species of
frequently have a pleasant odor; their foliage has been used as a stuffing material for pillows. Most commercial products with "pine odors" are in fact scented with essential oils distilled from
foliage by Russian farmers" (Hunt 1993).
" was the Latin name for an Old World species (Weber 1987).
Farjon, Aljos. 1990.
Pinaceae: drawings and descriptions of the genera Abies, Cedrus, Pseudolarix, Keteleeria, Nothotsuga, Tsuga, Cathaya, Pseudotsuga, Larix and Picea
. Königstein: Koeltz Scientific Books.
Farjon, Aljos. 2010.
A Handbook of the World's Conifers
. Leiden, Netherlands: Brill Academic Publishers.
Farjon, A. and K. D. Rushforth. 1989. A classification of
Notes of the Royal Botanic Garden Edinburgh
Hunt, Richard S. 1993. Abies. Flora of North America Editorial Committee (eds.): Flora of North America North of Mexico, Vol. 2. Oxford University Press.
Li Hui-Lin. 1975.
Flora of Taiwan
, V.1, parts 1-8. Taipei: Epoch Publishing.
Miller, P. 1754.
The Gardeners Dictionary
, abridged 4th edition. V.1, p.11.
Silba, J. 1986. An international census of the Coniferae.
memoir no. 8. Corvallis, OR: H.N. Moldenke and A.L. Moldenke.
Rushforth, K. D. 1987.
. New York: Facts on File. 232p.
Weber, William A. 1987.
Colorado Flora: Western Slope
. Niwot, Colorado: University Press.
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Edited by Christopher J. Earle
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Last Modified 2017-12-29