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The Douglas fir ( Pseudotsuga menziesii) is an evergreen conifer species in the pine family, Pinaceae. It is the tallest tree in the Pinaceae family. It is native plant to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. (2008). 9780470113691, John Wiley & Sons. ISBN 9780470113691 There are three varieties: coast Douglas-fir ( P. menziesii var. menziesii), Rocky Mountain Douglas-fir ( P. menziesii var. glauca) and Mexican Douglas-fir ( P. menziesii var. lindleyana).
Despite its , it is not a true fir (genus Abies), spruce (genus Picea), or pine (genus Pinus). It is also not a Tsuga (genus Tsuga); the genus name Pseudotsuga means "false hemlock".
There are records of former coast Douglas-firs exceeding in height, which if alive today would make it the tallest tree species on Earth. Particular historical specimens with heights exceeding include the Lynn Valley Tree and the Nooksack Giant.
The leaves are flat, soft, linear needles long, generally resembling those of the firs, occurring singly rather than in fascicles; they completely encircle the branches, which can be useful in recognizing the species. As the trees grow taller in denser forest, they lose their lower branches, such that the foliage may start as high as off the ground. Douglas-firs in environments with more light may have branches much closer to the ground.
The bark on young trees is thin, smooth, gray, and contains numerous resin blisters. On mature trees, usually exceeding 80 years, it is very thick and corky, growing up to thick with distinctive, deep vertical fissures caused by the gradual expansion of the growing tree. Some of the mature bark is brown, while other parts are lighter colored with a cork-like texture; these develop in multiple layers. This thick bark makes the Douglas-fir one of the most fire-resistant tree native to the Pacific Northwest.
The male Conifer cone are yellowish red, long. The female cones are green when young, maturing to reddish-brown or gray, long; they are pendulous, with persistent scales, unlike those of true firs. They have distinctive long, trifid (three-pointed) which protrude prominently above each scale and are said to resemble the back half of a mouse, with two feet and a tail. The seeds are long, with a longer wing.
The massive genome of Douglas-fir was sequenced in 2017 by the large PineRefSeq consortium, revealing a specialized photosynthetic apparatus in the light-harvesting complex of genes.
The specific epithet menziesii is after Archibald Menzies, a Scottish physician and rival Natural history to David Douglas. Menzies first documented the tree on Vancouver Island in 1791. Colloquially, the species is also known simply as Doug fir or Douglas pine (although the latter common name may also refer to Pinus douglasiana). Other names for this tree have included Oregon pine, British Columbian pine, Puget Sound pine, Douglas spruce, false hemlock, red fir, or red pine (although again red pine may refer to a different tree species, Pinus resinosa, and red fir may refer to Abies magnifica).
One Coast Salish name for the tree, used in the Halkomelem language, is italic=yes. In the Lushootseed language, the tree is called italic=yes.
Another variety exists further inland, Pseudotsuga menziesii var. glauca, the Rocky Mountain Douglas-fir or interior Douglas-fir. Interior Douglas-fir intergrades with coast Douglas-fir in the Cascades of northern Washington and southern British Columbia, and from there ranges northward to central British Columbia and southeastward to the Mexican border, becoming increasingly disjunct as latitude decreases and altitude increases. Mexican Douglas-fir ( P. lindleyana), which ranges as far south as Oaxaca, is often considered a variety of P. menziesii.
Fossils (wood, pollen) of Pseudotsuga are recorded from the Miocene and Pliocene of Europe (Siebengebirge, Gleiwitz, Austria).
It is also naturalised throughout Europe, Argentina and Chile (called Pino Oregón). In New Zealand it is considered to be an invasive species, called a wilding conifer, and is subject to control measures. But is also one of the most common lumber trees used in forestry alongside Radiata pine with large plantations throughout the country. The species was introduced in the 20th century for its wood.
The coast Douglas-fir variety is the dominant tree west of the Cascade Mountains in the Pacific Northwest. It occurs in nearly all forest types and competes well on most parent materials, aspects, and slopes. Adapted to a more moist, mild climate than the interior subspecies, it grows larger and faster than Rocky Mountain Douglas-fir. Associated trees include western hemlock, Sitka spruce, sugar pine, western white pine, ponderosa pine, grand fir, coast redwood, western redcedar, incense-cedar, Lawson's cypress, tanoak, bigleaf maple and several others. Pure stands are also common, particularly north of the Umpqua River in Oregon. It is most dominant in areas with a more frequent fire regime that suppresses less fire-resistant conifers.
Mature or "old-growth" Douglas-fir forest is the primary habitat of the red tree vole ( Arborimus longicaudus) and the spotted owl ( Strix occidentalis). Home range requirements for breeding pairs of spotted owls are at least of old growth. Red tree voles may also be found in immature forests if Douglas-fir is a significant component. The red vole nests almost exclusively in the foliage of the trees, typically above the ground, and its diet consists chiefly of Douglas-fir needles.
Douglas-fir needles are generally poor browse for , although in the winter when other food sources are lacking it can become important, and black-tailed deer browse new seedlings and saplings in spring and summer. The spring diet of the Dendragapus features Douglas-fir needles prominently.
The leaves are also used by the Adelgidae Adelges cooleyi; this 0.5 mm-long sap-sucking insect is conspicuous on the undersides of the leaves by the small white "fluff spots" of protective wax that it produces. It is often present in large numbers, and can cause the foliage to turn yellowish from the damage it causes. Exceptionally, trees may be partially defoliated by it, but the damage is rarely this severe. Among Lepidoptera, apart from some that feed on Pseudotsuga in general, the Chionodes abella and C. periculella as well as the cone scale-eating tortrix moth Cydia illutana have been recorded specifically on P. menziesii.
The inner bark is the primary winter food for the North American porcupine.
Poriol is a flavanone, a type of flavonoid, produced by P. menziesii in reaction to infection by Poria weirii.
The species is extensively used in forestry management as a plantation tree for softwood timber. Douglas-fir is one of the world's best timber-producing species and yields more timber than any other species in North America, making the forestlands of western Oregon, Washington, and British Columbia the most productive on the continent. In 2011, Douglas-fir represented 34.2% of US lumber exports, to a total of 1.053 billion board feet (2,484,803,3 cubic meters). Douglas-fir timber is used for timber frame construction and timber trusses using traditional joinery, Wood veneer, and Wood flooring due to its strength, hardness and durability. As of 2024, the only wooden ships still currently in use by the U.S. Navy in conventional naval operations are Avenger-class minesweepers, made of Douglas-fir.
Douglas-fir sees wide use in heavy timber structures, as its wood is strong, available in a number of specifications including kiln dried and grade stamped, and can be supplied in very long lengths to . West coast mills are sophisticated in their processing of timbers, making lead times predictable and availability reliable. adhere well to Douglas-fir. Wood stain perform well on Douglas-fir timbers with the mild caution that the natural color of this species varies and care must be taken to ensure uniformity of color. Pitch pockets that may ooze resin can be present in timbers that have not been kiln dried. Because of the timber sizes available, stamped timber grading, and relatively short lead times, Douglas-fir sees wide use in both public and residential projects.
The species has ornamental value in large parks and gardens. It has been commonly used as a Christmas tree since the 1920s, and the trees are typically grown on plantations.
The buds have been used to flavor eau de vie, a clear, colorless fruit brandy. Douglas-fir pine leaves can be used to make pine needle tea. They possess a tangy citrus flavor and may serve in some recipes as a wild substitute for rosemary.
Living examples in Canada include the Red Creek Fir in the San Juan Valley of Vancouver Island, the largest known Douglas-fir in Canada and one of the largest in the world; the Bonin Giant in the Coquitlam River watershed in British Columbia's Lower Mainland and Big Lonely Doug north of Port Renfrew on Vancouver Island..
American examples include the Lake Quinault Douglas fir in the Olympic National Forest, Washington State, the largest known Douglas fir in the United States; Coast Douglasfir (Pseudotsuga menziesii) champion, American Forests, listed 2018-09-05; accessed 2019-01-05 the Grandma Tree in North Fork Coquille River in Oregon, the second greatest of a living Douglas fir in the United States.; the Queets Fir, in the Olympic National Park in Washington State with the largest known in diameter; The Gymnosperm Database: Pseudotsuga menziesii subsp. menziesii, last modified 2018-12-23; accessed 2019-01-05 and the Doerner Fir fir in Coos County, Oregon.
Outside of North America, the Hermitage Douglas-fir in Dunkeld, Scotland was one of the tallest trees in the United Kingdom until it fell in 2017 and the Waldtraut of the mill forest, in Freiburg im Breisgau is the tallest tree in Germany.
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