No 5: The Douglas-fir

Douglas-fir, Pseudotsuga menziesii

Looking up at tall, skinny evergreen trees

Dave Nelson photo

Given the bewildering variety of new plant and animal species before him on the west side of the Rockies, it is all the more remarkable that Lewis was so thorough, orderly, and accurate in his observations, collections, and record-keeping. For instance, he enumerated six different evergreen conifer trees in the neighborhood of Fort Clatsop, which he sought to "discribe as well as my slender botanicall skill will enable me." He enumerated six of them, referring to all as "fir" trees.


"No. 5," he wrote on February 6, 1806:

medium-length pine needlesis a species of fir which arrives to the size of Nos. 2 [later, western hemlock] and 4 [possibly Pacific silver fir], the stem simple, branching, diffuse and proliferous. The bark thin, dark brown, much divided with small longitudinal interstices and sometimes scaleing off in thin rolling flakes. It affords but little rosin [pitch] and the wood is redish white 2/3ds of the diameter in the center, the ballance white, somewhat porus and tough. The twigs are much longer and more slender than in either of the other species. The leaves are acerose [needle-like], 1/20th of an inch in width, and an inch in length, sessile [without a stalk], inserted on all sides of the bough, streight, their extremities pointing obliquely toward the extremities of the bough and more thickly placed than in either of the other species; gibbous [convex] and flexeable but more stif than any except No. 1 [eventually named Sitka spruce, new to science] and more blontly pointed than either of the other species; the upper disk has a small longitudinal channel and is of a deep green tho' not so glossy as the balsam fir. The under disk is of a pale green.


Lewis's "No. 5" has come to own the name "Douglas-fir."1 (Notice the hyphen.)

It didn't come with a name, this giant of the vegetable kingdom, and as a north coast logger might put it, that's where the kerf grabs the blade. Botanists work from the proposition that if one studies the physiognomy, as it were, of a number of look-alikes, each will name itself according to the characteristics that mark it as a unique species, or subspecies. It's seldom been that simple, and it's often been temporary.


Stephen F. Arno, Northwest Trees (Seattle: The Mountaineers, 1977), pp. 67-74.

1. For the whole story, the serious student of botany is referred to Discovery Path Douglas Fir: A Nomenclatural Morass by James Reveal.