The "big, magestic" douglas-fir,
pseudotsuga menziesii

Before the murdered homecoming queen, the cherry pie, or the menacing doppelgängers of the Black Lodge, FBI Special Agent Dale Cooper drove into Twin Peaks, Washington, and fell in love with what he ecstatically called the “big, majestic” Douglas-fir. This beautiful conifer is one of the three tallest trees in North America, after the two species of Sequoia, with some reaching nearly 400’ in height and a life span beyond 750 years. Trees harvested before reaching these impressive heights provide most of the wood for the construction industry, as the wood is noted for its load-bearing strength. Its fast growth rate also makes it valuable to the Christmas tree industry.

Since its discovery, the tree has endured a dizzying taxonomic history. To begin with, Douglas-fir is not a fir tree (the genus Abies), as the hyphen in the name implies. It is in the genus Pseudotsuga, from the Latin “pseudo”, or “false”, and the Japanese “tsuga”, or “hemlock”, so it is not a hemlock, either. The path to its current scientific name has been a winding one. In 1803, it was Pinus taxifolia, “taxifolia” meaning with leaves similar to a yew (genus Taxus). In 1833, it was Abies douglasii; Pseudotsuga douglasii, in 1867; Pseudotsuga taxifolia; in 1889; and finally Pseudotsuga menziesii, in 1950. This is by no means a complete list.1

Two Scottish botanists are commemorated in both the common and scientific names of the Douglas-fir. In 1792, Archibald Menzies (1754–1842) collected the first specimens of the tree, on Vancouver Island, during the HMS Discovery’s five-year exploratory voyage under the command of Captain George Vancouver.2 In 1824, David Douglas (1799–1834), on an expedition for the London Horticultural Society, collected seeds of the tree along the Columbia River for cultivation in England.

Another twist in the Douglas-fir name game is the pronunciation of the species epithet. In Scotland, the name Menzies traditionally has been pronounced MING-iss, to rhyme with “sing”. Thus, the pronunciation of “menziesii” would be “MING-iss-ee-eye,” following the convention of retaining, as far as possible, the original pronunciation of the person’s name.

Two varieties of Douglas-fir grow in the western United States. Coastal Douglas-fir, Pseudotsuga menziesii var. menziesii, grows in the coastal and inland Pacific Northwest, from California to Canada, while Rocky Mountain Douglas-fir, Pseudotsuga menziesii var. glauca, occurs in the dry interior mountains, from the Mexican border to Canada. The coastal variety is by far the largest, with the tallest documented tree measured at 393’, in 1924.

This pen-and-ink illustration of the Douglas-fir shown at top right is one of Lucretia Hamilton’s unpublished drawings held by the University of Arizona Herbarium that was prepared for a planned allergenic plants publication (Desert Breeze Sep. 2016). In the drawing, note that the leaves, or needles, completely encircle the branch and occur singly, not in clusters as with pine trees. The downward-facing cone has distinctive bracts that extend beyond the scales of the cone. To the left of the cone is an enlarged bract attached to a scale. (The zoom tool is useful for viewing these details.)

The second illustration is from the French publication, Traité des arbres et arbrissaux (Treatise of trees and shrubs), by botanist and dendrologist Pierre Mouillefert. This illustration includes a fruiting branch with pendulous cones and their prominent bracts (center) and also a flowering branch (top right) with male flowers at the bottom left of the branch and female flowers at the top right.

The unusual bracts that emerge from beneath the scales of the Douglas-fir cone are said to resemble the hind legs and tail of a mouse, as described in a legend from the Pacific northwest. During a raging wildfire, a mouse ran through the forest asking the tall trees to shelter him from the fire. Only the great Douglas-fir tree took pity on the mouse and invited him to hide beneath the scales of his pine cones to avoid the fire. Zoom in on the bottom illustration at right to see the mice hiding within the pine cone.

Several additional illustrations of the tree can be view in this gallery, which includes an excellent drawing by Charles Edward Faxon and a drawing from William Jackson Hooker's Flora boreali-americana, which somehow manages to invert the cones.— Cindy Hartwell

1  The nomenclatural ins-and-outs of these changes are detailed in Douglas-fir: A Nomenclatural Morass, a fascinating account by the late botanist James Reveal.

2  Captain Vancouver's name graces many locations in New Zealand and Australia as well as the Pacific Northwest. He named several locations in the Pacific Northwest for his associates and countrymen:
Mount St. Helens - named by the Captain for a British diplomat, Baron St. Helens, who had settled a the Nootka crisis, a serious dispute between Britain, Spain, and America over conflicting claims to land in the Pacific Northwest;
Mount Baker - named for Discovery's 3rd Lieutenant Joseph Baker, who had been the first on the ship to spot the mountain;
Puget Sound and Puget Island - named for Discovery's 2nd Lieutenant Peter Puget who did much of the surveying work in the area around present-day Seattle;
Mount Hood - named by Lt. William Broughton, commander of the HMS Chatham, Discovery's sister ship for Admiral Samuel Hood, the British Naval officer who had found in the Battle of the Chesapeake;
Mount Rainier - named by Vancouver for his friend Rear Admiral Peter Rainer, a veteran of many battles in the American Revolutionary War.

An abbreviated version of this article appeared in the December 2019 issue of the Desert Breeze, the monthly newsletter of the Tucson Cactus and Succulent Society.