Three days later, on February 9, 1806, Lewis found more to say.
In the marshy ground frequently overflown by the tides there grows a species of fir which I take to be the same [as] No. 5 which it resembles in every particular except that it is more defusely [irregularly] branched and not so large, being seldom more than 30 feet high and 18 inches or 2 feet in diameter. It's being more defusely branched may proceed from it's open situation, seldom growing very close. The cone is 2-1/2 inches in length and 3-3/4 in it's greatest circumpherence, which is near it's base, and from which it tapers regularly to a point. It is formed of imbricated [overlapping] scales of a bluntly rounded form, thin, not very firm, and smooth. A thin leaf is inserted into the pith of the cone, which overlays the center of and extends 1/2 an inch beyond the point of each scale.
In 1790, Archibald Menzies, a Scottish physician and naturalist, was appointed by the British government to accompany Captain George Vancouver on a global tour in the good ship Discovery. His main responsibility was to observe and describe the plants at the places he visited, record their scientific as well as Indian names, and note whether English settlers might be able to thrive in each place as farmers. On Vancouver Island, now part of the province of British Columbia, he made passing note of a tree that was new to him—the same one Lewis was to examine more closely 16 years later.
The tree still didn't have a name when the Royal Horticultureal Society of London sent another Scotsman, David Douglas, to the American Northwest. Douglas and his party anchored in Baker's Bay on April 17, 1825. It was about to get a name of its own, borrowed from Douglas. It was still viewed as a pine—"Oregon pine," some called it—although its needles grow singly rather than in clusters, and its cones are quite different from a pine's. Moreover, it shares certain characteristics with the species known as fir (in Latin, Abies, AY-beez), as well as with the spruce (Picea, PIE-see-uh) and the yew (Taxus, TAX-us). The Scottish-American naturalist John Muir dubbed it "Douglas spruce," but some of his contemporaries thought it was a hemlock.
In 1867, new discoveries in China and Japan led to a compromise, and the name Pseudotsuga (SOO-doh-TSOO-ga), meaning "false hemlock," plus douglasii in honor of David Douglas. That name was soon replaced by Pseudotsuga taxifolia, meaning "false hemlock with leaves like a yew." Then, appealing to a technicality in botanical naming procedure, another botanist proposed Pseudotsuga menzesii (men-ZEE-see-eye), because Archibald Menzies got there first.
Nearly two hundred years' worth of disagreements notwithstanding, the accepted common name in English today is properly written as Douglas-fir, the hyphen somehow diminishing the responsibility of the second noun, even if only to the eye.1 More common still is the name that brings to mind a living-room-sized pyramidal plant with a dense foliage of green leaves—all right, then, "needles"—and above all a heady, resinous aroma that spells . . . "Christmas tree!"2
Douglas-fir trees on the Northwest coast can live 750 years or more, reach heights of over 200 feet, and diameters of 4 to 8 feet. Its wood is of prime importance for building purposes, and especially for the manufacture of plywood.
Stephen F. Arno, Northwest Trees (Seattle: The Mountaineers, 1977), pp. 67–74.
2. There's one more: Poetically, Tann is the German word for "pine forest." More specifically, it means "fir." Baum is German for "tree." So a Tannenbaum is a "fir tree." No hyphen.