Abies balsamea

Balsam fir is a small to medium-size evergreen tree typically 14–20 metres (46–66 ft) tall, occasionally reaching a height of 27 metres (89 ft). The narrow conic crown consists of dense, dark-green leaves. The bark on young trees is smooth, grey, and with resin blisters (which tend to spray when ruptured), becoming rough and fissured or scaly on old trees. The leaves are flat and needle-like, 15 to 30 mm (⁵⁄₈ to 1 ¹⁄₈ in) long, dark green above often with a small patch of stomata near the tip, and two white stomatal bands below, and a slightly notched tip. They are arranged spirally on the shoot, but with the leaf bases twisted so that the leaves appear to be in two more-or-less horizontal rows on either side of the shoot. The needles become shorter and thicker the higher they are on the tree. The seed cones are erect, 40 to 80 mm (1 ¹⁄₂ to 3 ¹⁄₄ in) long, dark purple, ripening brown and disintegrating to release the winged seeds in September.

There are two varieties:

• Abies balsamea var. balsamea (balsam fir) – bracts subtending seed scales short, not visible on the closed cones. Most of the species' range.
• Abies balsamea var. phanerolepis (bracted balsam fir or Canaan fir) – bracts subtending seed scales longer, visible on the closed cone. The southeast of the species' range, from southernmost Quebec to West Virginia. The name Canaan fir derives from one of its native localities, the Canaan Valley in West Virginia. Some botanists regard this variety as a natural hybrid between balsam fir and Fraser fir (Abies fraseri), which occurs further south in the Appalachian mountains.

Balsam fir krummholz on Mount Hight, New Hampshire

Balsam firs tend to grow in cool climates, ideally with a mean annual temperature of 40 °F (4 °C), with consistent moisture at their roots. They typically grow in the following four forest types:

• Swamp – swamp forest types never completely dry out, so balsam firs have constant access to water. The ground is covered in sphagnum and other mosses. In swamps, balsam firs grow densely and slowly, and are slender.
• Flat – sometimes referred to as "dry swamps," these areas are better drained than swamps but still retain moisture well. Fern moss covers the ground and there is a possibility of ground rot. In flat areas balsam fir grows fast, tall, and large, mixed with red spruce.
• Hardwood slope – ground rot is common in this well-drained area, and leaf litter covers the forest floor. Balsam firs grow fast, tall, and large along with big hardwood trees such as yellow birch, sugar maple and beech.
• Mountain top – On mountain tops, stands of balsam fir occasionally develop fir waves. They often grow at an elevation of 760 to 1,520 m (2,500 to 5,000 ft) in pure strands, or in association with black spruce, white spruce, and trembling aspen. The development is similar to that in swamps with slow growth resulting in slender, short trees. Some of the low branches touch the ground, and may grow roots to produce an independent tree.[6]

The foliage is browsed by moose and deer.[7] The seeds are eaten by American red squirrels, grouse, and pine mice;[8] the tree also provides food for crossbills and chickadees, as well as shelter for moose, snowshoe hares, white-tailed deer, ruffed grouse, and other small mammals and songbirds. The needles are eaten by some lepidopteran caterpillars, for example the Io moth (Automeris io).

Abies balsamea is one of the most cold-hardy trees known, surviving at temperatures as low as −45 °C (−49 °F) (USDA Hardiness Zone 2). Specimens even showed no ill effects when immersed in liquid nitrogen at −196 °C (−320.8 °F).[9]

Balsam fir essential oil in clear glass vial

The resin is used to produce Canada balsam, and was traditionally used as a cold remedy and as a glue for glasses, optical instrument components, and for preparing permanent mounts of microscope specimens. Given its use as a traditional remedy and the relatively high ascorbic acid content of its needles, historian Jacques Mathieu has argued that the balsam fir was the "aneda" that cured scurvy during the second expedition into Canada of Jacques Cartier.[16] The wood is milled for framing lumber (part of SPF lumber), siding and pulped for paper manufacture. Balsam fir oil is an EPA approved nontoxic rodent repellent. The balsam fir is also used as an air freshener and as incense.[17]

Prior to the availability of foam rubber and air mattresses, balsam fir boughs were a preferred mattress in places where trees greatly outnumbered campers. Many fir limbs are vertically bowed from alternating periods of downward deformation from snow loading and new growth reaching upward for sunlight. Layers of inverted freshly cut limbs from small trees created a pleasantly fragrant mattress lifting bedding off the wet ground; and the bowed green limbs were springs beneath the soft needles. Upper layers of limbs were placed with the cut ends of the limbs touching the earth to avoid uncomfortably sharp spots and sap.[18]

The Native Americans used it for a variety of medicinal purposes.[19]

Balsam fir is the provincial tree of New Brunswick.

• Balsam of Peru
• Fraser fir

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  Bark
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  Leaves (needles) on symmetrical branchlets
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  Closeup of thickly leaved branchlets
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  Pollen cones
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  Seed cones with resin oozing out in the Mingan Archipelago, Quebec

• Hunt, Richard S. (1993). "Abies balsamea". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). 2. New York and Oxford – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
• Karen Legasy, Shayna LaBelle-Beadman & Brenda Chambers. Forest Plants of Northeastern Ontario. Lone Pine Publishing / Queen's Printer for Ontario, 1995.

Wikimedia Commons has media related to: Abies balsamea (category)

• Gymnosperm Database: Abies balsamea
• Winter ID pictures
• Compiled images
• Interactive Distribution Map of Abies balsamea