red fir: see pine.

fir, any tree of the genus Abies of the family Pinaceae (pine family), tall pyramidal evergreen conifers characterized by short, flat, stemless needles and erect cylindrical cones that shed their scales rather than dropping off the tree whole. Firs, valued and cultivated for their fragrance and beauty, are found chiefly in alpine regions of the Northern Hemisphere. In North America the balsam fir, or balsam, popular as a Christmas tree and the source of Canada balsam, is native to the Northeast; the Fraser fir, or she-balsam, grows in the Alleghenies and is used as a Christmas tree; and the noble, alpine, and red firs are found at high altitudes and the grand, silver, and white firs on lower mountain slopes in the Northwest. Fir wood is usually light and soft but is sometimes used for interior finishing and for crates and boxes. The Douglas fir, Pseudotsuga menziesii, is not a true fir (see pine). Firs are classified in the division Pinophyta, class Pinopsida, order Coniferales.

balsam fir, common name for the evergreen tree Abies balsamea of NE North American boreal forests. It has small needles and cones and is used for lumber. It is also called Canada balsam, as is the resin it produces, which is used as an adhesive in optical lenses and glass slides. Balsam fir is classified in the division Pinophyta, class Pinopsida, order Coniferales, family Pinaceae.

Douglas fir: see pine.

Properly, any of about 40 species of trees that make up the genus Abies, in the pine family. Many other evergreen conifers (e.g., Douglas fir, hemlock fir) are also commonly called firs. True firs are native to North and Central America, Europe, Asia, and northern Africa. They are distinguished from other genera in the pine family by their needlelike leaves, which grow directly from the branch and have bases, shaped like suction cups, that leave conspicuous circular scars when the leaves fall. North America boasts 10 native species of fir, found chiefly from the Rocky Mountains westward. The wood of most western North American firs is inferior to that of pine or spruce but is used for lumber and pulpwood. Of the two fir species that occur in the eastern U.S. and Canada, the better known is the balsam fir (A. balsamea), a popular ornamental and Christmas tree.

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Any of about six species of coniferous evergreen timber trees (see conifer) that make up the genus Pseudotsuga, in the pine family, native to western North America and eastern Asia. Long, flat, spirally arranged yellow- or blue-green needles grow directly from the branch. The North American tree commonly called Douglas fir is P. menziesii (sometimes P. douglasii). Douglas firs may grow to 250 ft (75 m) tall and 8 ft (2.4 m) in diameter. One of the best timber trees in North America, it is also a popular ornamental and Christmas tree and is used for reforestation along the Pacific Coast.

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