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Pseudotsuga taxifolia

Pseudotsuga menziesii is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is known as Douglas fir, Douglas-fir, Oregon pine, and Columbian pine. There are two varieties: coast Douglas-fir (P. menziesii var. menziesii), and Rocky Mountain Douglas-fir (P. menziesii var. glauca). 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 Pseudotsuga as a whole). The specific epithet menziesii is after Archibald Menzies, a Scottish physician and rival naturalist 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 the latter may refer to a different tree species—Pinus resinosa). One Coast Salish name for the tree, used in the Halkomelem language, is lá:yelhp. 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 heights). The leaves are flat, soft, linear, 2–4 centimetres (3⁄4–1 1⁄2 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 those of 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). Pseudotsuga menziesii var. menziesii, the coast Douglas-fir, grows in the coastal regions from west-central British Columbia southward to central California. In Oregon and Washington, its range is continuous from the eastern edge of the Cascades west to the Pacific Coast Ranges and Pacific Ocean. In California, it is found in the Klamath and California Coast Ranges as far south as the Santa Lucia Range, with a small stand as far south as the Purisima Hills in Santa Barbara County. One of the last remaining old growth stands of conifers is in the Mattole Watershed, and is under threat of logging. In the Sierra Nevada, it ranges as far south as the Yosemite region. It occurs from near sea level along the coast to 1,800 m (5,900 ft) above sea level in the mountains of California. 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.

[ "Ecology", "Botany", "douglas fir" ]
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