PSEUDOTSUGA MENZIESII, commonly known as DOUGLAS FIR or DOUGLAS-FIR,
is an evergreen conifer species native to western
* 1 Naming * 2 Description * 3 Distribution * 4 Ecology * 5 Uses * 6 See also * 7 References * 8 Further reading * 9 External links
The common name honors David Douglas , a Scottish botanist and
collector who first reported the extraordinary nature and potential of
the species. The common name is misleading since it is not a true fir,
i.e., not a member of the genus
Abies . For this reason the name is
often written as DOUGLAS-FIR (a name also used for the genus
The specific epithet, menziesii, is after
Archibald Menzies , a
Scottish physician and rival naturalist to David Douglas . Menzies
first documented the tree on
Douglas firs are medium-size to extremely large evergreen trees , 20–100 metres (70–330 ft) tall (although only coast Douglas firs reach such great height). The leaves are flat, soft, linear, 2–4 centimetres (0.8–1.6 in) 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 high off the ground. Douglas firs in environments with more light may have branches much closer to the ground.
The female cones are pendulous, with persistent scales unlike true firs. They are distinctive in having a long tridentine (three-pointed) bract that protrudes prominently above each scale (it resembles the back half of a mouse, with two feet and a tail).
One variety , coast
Douglas fir (
Further inland, coast Douglas fir is replaced by another variety, Rocky Mountain or interior Douglas fir (P. menziesii var. glauca). 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.
Douglas-fir prefers acidic or neutral soils. However, Douglas fir exhibits considerable morphological plasticity, and on drier sites coast Douglas fir will generate deeper taproots. Interior Douglas fir exhibits even greater plasticity, occurring in stands of interior temperate rainforest in British Columbia, as well as at the edge of semi-arid sagebrush steppe throughout much of its range, where it generates even deeper taproots than coast Douglas fir is capable. A snag provides nest cavities for birds
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 400 ha (4 square kilometres, 990 acres) of old-growth. Red tree voles may also be found in immature forests if Douglas fir is a significant component. This animal nests almost exclusively in the foliage of Douglas fir trees. Nests are located 2–50 metres (5–165 ft) above the ground. The red vole's diet consists chiefly of Douglas fir needles. A parasitic plant sometimes utilizing P. menziesii is Douglas-fir dwarf mistletoe (Arceuthobium douglasii).
The leaves are also used by the woolly conifer aphid 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 in causes.
Exceptionally, trees may be partially defoliated by it, but the damage
is rarely this severe. Among
Lepidoptera , apart from some that feed
Douglas fir variety is the dominant tree west of the
Cascade Mountains in the
Pacific Northwest , occurring in nearly all
forest types, competes well on most parent materials, aspects, and
slopes. Adapted to a moist, mild climate, it grows larger and faster
than Rocky Mountain
Douglas fir . Associated trees include western
This plant has ornamental value in large parks and gardens.
Away from its native area, it is also extensively used in forestry as a plantation tree for timber in Europe, New Zealand, Chile and elsewhere. It is also naturalised throughout Europe, Argentina and Chile (called Pino Oregón), and in New Zealand sometimes to the extent of becoming an invasive species (termed a wilding conifer ) subject to control measures.
The buds have been used to flavor eau de vie , a clear, colorless fruit brandy.
Native Hawaiians built waʻ kaulua (double-hulled canoes ) from coast Douglas fir logs that had drifted ashore.
* Trees portal
* List of Douglas-fir diseases * Tree: A Life Story
* ^ Farjon, A. (2013). "