Trees to 23m; trunk to 0.6m diam.; crown spirelike. Bark gray, thin, smooth, in age often becoming broken into irregular brownish scales. Branches diverging from trunk at right angles, the lower often spreading and drooping; twigs mostly opposite, greenish brown, pubescence sparse. Buds hidden by leaves or exposed, brown, conic, small, resinous, apex acute; basal scales short, broad, nearly equilaterally triangular, glabrous, resinous, margins entire, apex sharp-pointed. Leaves 1.2--2.5cm ´ 1.5--2mm, 1-ranked (particularly on lower branches) to spiraled, flexible; cross section flat, grooved adaxially; odor pinelike (copious ß-pinene); abaxial surface with (4--)6--7(--8) stomatal rows on each side of midrib; adaxial surface dark green, slightly or not glaucous, with 0--3 stomatal rows at midleaf, these more numerous toward leaf apex; apex slightly notched to rounded; resin canals large, ± median, away from margins, midway between abaxial and adaxial epidermal layers. Pollen cones at pollination red, purplish, bluish, greenish, or orange. Seed cones cylindric, 4--7 ´ 1.5--3cm, gray-purple, turning brown before scale shed, sessile, apex round to obtuse; scales ca. 1--l.5 ´ 0.7--1.7cm (relationship reversed in more western collections), pubescent; bracts included or exserted and reflexed over scales. Seeds 3--6 ´ 2--3mm, body brown; wing about twice as long as body, brown-purple; cotyledons ca. 4. 2 n =24. Boreal and northern forests; 0--1700m; St. Pierre and Miquelon; Alta., Man., N.B., Nfld., N.S., Ont., P.E.I., Que., Sask.; Conn., Iowa, Maine, Mass., Mich., Minn., N.H., N.Y., Pa., Vt., Va., W.Va., Wis. Balsam fir is frequently segregated into two varieties (e.g., H.J. Scoggan 1978--1979) based on whether the bracts are included (var. balsamea ) or exserted (var. phanerolepis Fernald), the latter considered by Liu T. S. (1971) to be a hybrid between Abies balsamea and A . fraseri . D.T. Lester (1968) demonstrated, however, that bract length may vary within a cone, annually, and from tree to tree. Nevertheless, a tendency exists for the exserted variety to be found most commonly from Newfoundland south through New England (R.C. Hosie 1969; B.F. Jacobs et al. 1984); it is not found west of Ontario. Western populations lack 3-carene and have other minor chemical differences separating them from eastern balsam fir (E.Zavarin and K.Snajberk 1972; R.S. Hunt and E.von Rudloff 1974). Morphologic variation in balsam fir has been studied mainly east of Ontario; the populations to the west have been ignored for the most part, although they may yield stronger evidence for species subdivision. In Alberta, populations intermediate between western Abies balsamea and A . bifolia (E.H. Moss 1953; R.S. Hunt and E.von Rudloff 1974, 1979) may be classified as A . balsamea ´ bifolia . In West Virginia and Virginia, populations of balsam fir tend to be more similar to A . fraseri than are more northern populations (B.F. Jacobs et al. 1984).

Balsam fir ( Abies balsamea ) is the provincial tree of New Brunswick.