According to Indo-Europeanists Gamkrelidze and Ivanov, "The semantics of the term clearly points to a connection between 'oak' and mountainous regions, which is the basis for the ancient European term applied to forested mountains" (such as Gothic fairgunni "mountainous region," Old English firgen "mountain forest," Middle High German Virgunt "mountain forest; Sudetes"). In the period 3300 B.C.E. to 400 B.C.E., conifers and birches gradually displaced oaks in northern European forests. "Hence it is no surprise that in the early history of the Germanic languages the ancient term for mountain oak and oak forest shifts to denote conifers and coniferous forests." [Thomas V. Gamkrelidze, Vjaceslav V. Ivanov, "Indo-European and the Indo-Europeans," Berlin, 1994]
tree genus, Latin quercus "oak," from PIE *kwerkwu-, assimilated form of *perkwu- "oak" (see fir). Related: Quercine (adj.).
"coniferous tree, tree of the genus Pinus," Old English pin (in compounds), from Old French pin and directly from Latin pinus "pine, pine-tree, fir-tree," which is perhaps from a PIE *pi-nu-, from root *peie- "to be fat, swell" (see fat (adj.)).
If so, the tree's name would be a reference to its sap or pitch. Compare Sanskrit pituh "juice, sap, resin," pitudaruh "pine tree," Greek pitys "pine tree." Also see pitch (n.1). The native Old English word was furh (see fir). Pine-top "cheap illicit whiskey," is attested by 1858, Southern U.S. slang.
Most of us have wished vaguely & vainly at times that they knew a fir from a pine. As the Scotch fir is not a fir strictly speaking, but a pine, & as we shall continue to ignore this fact, it is plain that the matter concerns the botanist more than the man in the street. [Fowler]
Spruce seems to have been a generic term for commodities brought to England by Hanseatic merchants (especially beer, boards and wooden chests, and leather), and the tree thus was believed to be particular to Prussia, which for a time was figurative in England as a land of luxuries. Compare spruce (adj.).
As a distinct species of evergreen tree from 1731. Nearly all pines have long, soft needles growing in groups of two (Scotch) to five (white); spruce and fir needles grow singly. Spruce needles are squarish and sharp; fir needles are short and flat. Cones of the fir stand upright; cones of a spruce hang before falling.
"plank or board," especially of fir or pine, late 14c., dele, from Low German (compare Middle Low German dele), from Proto-Germanic *theljon." From late 13c. in surnames. An Old English derivative was þelu"hewn wood, board, flooring."