Which larch is which? Getting to know our golden fall trees

By Brian Baxter

 

Part of the beauty of autumn in northwest Montana is when mother nature weaves her alchemy, and our larch trees’ needles turn to gold. Our awesome local outdoor photographers make this change a focal point of their lenses, that we all can appreciate. As we take to the woods to bow hunt and teach our young hunters to rifle hunt, the beauty of our surroundings is a shared component of our enjoyment and bonding.

For those of us big game hunting the higher elevations roughly above 6,000 feet, we are treated to the amber tones of Larix lyallii, commonly known as subalpine, alpine, or Lyall larch. These larch trees usually occur in the spruce fir zone. Near the timberline, these trees are often stunted, gnarled, and usually max out at about 65 feet in height. The crown is broad, and limbs spread out. The young twigs are covered with dense wooly hair, bark is initially ash gray and smooth, becoming brownish with age, and deeply furrowed. Sub-alpine larch needles are deciduous, have about 35 needles on each short spur, are four angled with visible resin ducts in cross section, and usually drop in early to mid fall. Cones are reddish-yellow and one to two inches long.

The more commonly occurring Western larch, is locally know as Tamarack. This species is generally found at lower elevations than the alpine larch, and the western larch is scientifically named Larix occidentalis. Tamarack is a well preferred timber species, as it grows to over 200 feet tall, has a short, open crown with a long clear bole, and often has a swelling at the butt. The young twigs on this species are hairless. The bark is initially thin and scaly, but as the tree ages, becomes thick and deeply furrowed. Large plates then form, which flake into cinnamon red scales. The needles are deciduous, average about 25 needles to each short spur, are triangular, and have no visible resin ducts in cross section. The tawny needles usually fall in late autumn. Cones are oblong, borne upright, red-brown in color and less than two inches long.

Both of our local larch species are used by wildlife. In higher elevations, alpine larch may be used as perching trees by hawks, owls, and Peregrine falcons. Lower elevation Western larch are used as escape trees for bears, and are often marked as wildlife trees by forest professionals. Tamaracks are also used for hunting and nesting sites by Goshawks, Great Horned, Barred, Saw-whet, and Northern Pygmy owls, as well as a variety of woodpeckers.

Western larch is very fire resistant, due to thick bark up to six inches at the base of the trunk. Also, it is a self pruning tree and this eliminates ladder fuels, the crowns occur higher up in the tree, and these larch have a low resin content. The needles are not very flammable, because they are replaced every year. Tamarack is a choice firewood, and burns hot and clean. Native Americans made a chewing gum from the resin, as well as syrup. Nez Perce peoples made a tea from the bark to treat colds and coughs. Medicinal compounds in larix occidentalis leaves and stems are antirheumatic, antiseptic, appetizers, and blood purifiers. A concoction of Western larch has been used internally and externally to treat some forms of cancer too.