The western larch (''Larix occidentalis'') is a species of

larch Larches are deciduous conifers in the genus ''Larix'', of the family Pinaceae (subfamily Laricoideae). Growing from tall, they are native to much of the cooler temperate northern hemisphere, on lowlands in the north and high on mountains furt ...

native to the mountains of western

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

(

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

Inland Northwest The Inland Northwest, historically and alternatively known as the Inland Empire, is a region of the American Northwest centered on the Greater Spokane, Washington Area, encompassing all of Eastern Washington and North Idaho. Under broader def ...

); in

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

in southeastern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

and southwestern

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

, and in the

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in eastern

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

, eastern

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

, northern

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

, and western

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

. It is the most productive of the three species of larch native to North America.

Description

The tree is a large

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...

reaching tall, with a trunk up to diameter; the bark ranges from orangish to purplish brown. The crown is narrow conic; the main branches are level to upswept, with the side branches often drooping. The shoots are dimorphic, with growth divided into long shoots (typically long) and bearing several

bud In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of a stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be spec ...

s, and short shoots only long with only a single bud. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are needle-like, light green, long, soft and very slender; they turn bright yellow in the fall, leaving the pale orange-brown shoots bare until the next spring. The seed

cones A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines conn ...

are ovoid-cylindric, long, with 40 to 80 seed scales; each scale bearing an

exserted This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

. The cones are green to reddish purple when immature, turning brown and the scales opening flat or reflexed to release the

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s when mature, four to six months after pollination. The old cones commonly remain on the tree for many years, turning dull gray-black. Individual specimens can live centuries, even up to a millennium. The largest known specimen is about 1,000 years old, tall and over in diameter with a crown, located at

Seeley Lake, Montana Seeley Lake is a census-designated place (CDP) in Missoula County, Montana, United States. It is part of the 'Missoula, Montana Metropolitan Statistical Area'. The town sits beside the 1,031.5 acres lake Seeley Lake. The population was 1,659 at ...

Distribution

Western larch grows almost exclusively in the drainage of the

Columbia River The Columbia River (Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, C ...

, from the east of the

Cascade Range The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

to the west of the

Continental Divide A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not ...

. It covers the regions from around

Kamloops Kamloops ( ) is a city in south-central British Columbia, Canada, at the confluence of the South flowing North Thompson River and the West flowing Thompson River, east of Kamloops Lake. It is located in the Thompson-Nicola Regional District, w ...

, to

Weiser, Idaho Weiser ( ) is a city in the rural western part of the U.S. state of Idaho and the county seat of Washington County. With its mild climate, the city supports farm, orchard, and livestock endeavors in the vicinity. The city sits at the confluence o ...

, and

Central Oregon Central Oregon is a geographic region in the U.S. state of Oregon and is traditionally considered to be made up of Deschutes, Jefferson, and Crook counties. Other definitions include larger areas, often encompassing areas to the north towards the ...

. It appears on ranges including the Blue Mountains and others in southeast BC and northwest

, usually on moist slopes up to above sea level. It can grow from elevations between and is very cold tolerant, able to survive winter temperatures down to about . It only grows on well-drained soils, unable to thrive on waterlogged ground.

Ecology

Western larch grows more quickly than many associated trees, as it needs to because larch is shade intolerant. With its thick bark, nonflammable foliage and protective cones, the species is very fire resistant. In the late 20th century, after wildfires had been suppressed for almost a century, larches at Seeley Lake and Glacier National Park were endangered by major fires enabled by

fuel ladder A fuel ladder or ladder fuel is a firefighting term for live or dead vegetation that allows a fire to climb up from the landscape or forest floor into the tree canopy. In more recent years, many smaller fires have been allowed to take their course. Grouse browse the tree's leaves and buds. The seeds are an important substitute winter food for some birds, notably the

pine siskin The pine siskin (''Spinus pinus'') is a North American bird in the finch family. It is a migratory bird with an extremely sporadic winter range. Taxonomy The pine siskin was formally described in 1810 by the American ornithologist Alexander ...

but also the

redpoll The redpolls (genus ''Acanthis'') (in Great Britain also historically known as redpoles) are a group of small passerine birds in the finch family Fringillidae, which have characteristic red markings on their heads. They are placed in the genus ' ...

, and white-winged crossbill. This is frequently during times when other conifer cones that are a more preferred diet are in short supply. Woodpeckers utilize the

heart rot 300px, The bracket fungus '' Fistulina hepatica'' is one of many that cause heart rot. In trees, heart rot is a fungal disease that causes the decay of wood at the center of the trunk and branches. Fungi enter the tree through wounds in the bark ...

of older specimens to make openings, which are used by various small animals.

Assisted migration

In 2010, the

Government of British Columbia The Government of British Columbia (french: Gouvernement de la Colombie-Britannique) is the body responsible for the administration of the Canadian province of British Columbia. A constitutional monarchy, the Crown is the corporation sole, assumi ...

implemented an

assisted migration According to ''A Dictionary of Ecology'', assisted migration is "the intentional establishment of populations or meta-populations beyond the boundary of a species' historic range for the purpose of tracking suitable habitats through a period of c ...

program of western larch to a new habitat in northern British Columbia, about 1000 kilometers north of its current range. Assisted migration of Canadian forests had been proposed as an adaptation measure in response to

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

. Indeed, as average temperatures rise, the optimal climate conditions for trees species are also moving North. Research had shown that western larch trees have no trouble growing in northern BC, an area whose climatic conditions are predicted to match the western larch's historical range by 2030. British Columbia started seeding western larch trees in northern BC in the early 2010s. This was the first assisted migration program for a North American tree. The western larch was selected for because of its significant commercial importance and the fear that

and parasites such as the

mountain pine beetle The mountain pine beetle (''Dendroctonus ponderosae'') is a species of bark beetle native to the forests of western North America from Mexico to central British Columbia. It has a hard black exoskeleton, and measures approximately , about the siz ...

would considerably diminish its supply. To pre-empt opposition from biologists and other groups, the government avoided making public consultation on the program. Instead, they framed the policy as an introduction of a non-exotic species to a similar environment, and implemented the program through the province's existing legal and regulatory framework. Foresters in the United States have also initiated "experimental treatments" of larch-dominated national forests in Montana. However, if some "aggressively warming climate scenarios" actually unfold, foresters will need to let go of any expectations of helping this species maintain a presence south of the Canadian border.

Uses

Indigenous peoples applied the resinous gum to injuries and chewed it to treat sore throat. Some also ate the

cambium A cambium (plural cambia or cambiums), in plants, is a tissue layer that provides partially undifferentiated cells for plant growth. It is found in the area between xylem and phloem. A cambium can also be defined as a cellular plant tissue from w ...

and sap; the

Kutenai The Kutenai ( ), also known as the Ktunaxa ( ; ), Ksanka ( ), Kootenay (in Canada) and Kootenai (in the United States), are an indigenous people of Canada and the United States. Kutenai bands live in southeastern British Columbia, northern ...

and

Salish peoples The Salish peoples are indigenous peoples of the American and Canadian Pacific Northwest, identified by their use of the Salish languages which diversified out of Proto-Salish between 3,000 and 6,000 years ago. The term “Salish” originated i ...

of Montana in particular collected the sap. A medicinal tea was made from the bark or foliage. Some

Plateau Indian Indigenous peoples of the Northwest Plateau, also referred to by the phrase Indigenous peoples of the Plateau, and historically called the Plateau Indians (though comprising many groups) are indigenous peoples of the Interior of British Columbia ...

tribes drank an infusion from the young shoots to treat

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...

and

laryngitis Laryngitis is inflammation of the larynx (voice box). Symptoms often include a hoarse voice and may include fever, cough, pain in the front of the neck, and trouble swallowing. Typically, these last under two weeks. Laryngitis is categorised ...

. The sweetish

galactan Galactan (galactosan) is a polysaccharide consisting of polymerized galactose. In general, galactans in natural sources contain a core of galactose units connected by α(1→3) or α(1→6), with structures containing other monosaccharides M ...

of the sap can be made into baking powder and medicine. An extract of the tree is sold as a health supplement. The water-soluble

arabinogalactan Arabinogalactan, also known as galactoarabinan, larch arabinogalactan, and larch gum, is a biopolymer consisting of arabinose and galactose monosaccharides. Two classes of arabinogalactans are found in nature: plant arabinogalactan and microbial a ...

is used in food, medicine, ink, and paint. The

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...

is tough and durable, but also flexible in thin strips, and is particularly valued for

yacht A yacht is a sailing or power vessel used for pleasure, cruising, or racing. There is no standard definition, though the term generally applies to vessels with a cabin intended for overnight use. To be termed a , as opposed to a , such a pleasu ...

building; wood used for this must be free of knots, and can only be obtained from old trees that were pruned when young to remove side branches. Small larch poles are widely used for rustic fencing. The wood is highly prized as

firewood Firewood is any wooden material that is gathered and used for fuel. Generally, firewood is not highly processed and is in some sort of recognizable log or branch form, compared to other forms of wood fuel like pellets or chips. Firewood can ...

in the

where it is often called "tamarack," although it is a different species than the

tamarack larch ''Larix laricina'', commonly known as the tamarack, hackmatack, eastern larch, black larch, red larch, or American larch, is a species of larch native to Canada, from eastern Yukon and Inuvik, Northwest Territories east to Newfoundland, and als ...

. The wood burns with a sweet fragrance and a distinctive popping noise. Western larch is used for the production of

Venice turpentine Turpentine (which is also called spirit of turpentine, oil of turpentine, terebenthene, terebinthine and (colloquially) turps) is a fluid obtained by the distillation of resin harvested from living trees, mainly pines. Mainly used as a special ...

Gallery

References

External links

''Larix occidentalis'' images at the Arnold Arboretum of Harvard University Plant Image DatabaseCatalog of Life - Conifer Database - Larix occidentalis Nutt.
{{Taxonbar, from=Q576585 Trees of the Northwestern United States Trees of British Columbia Trees of Alberta occidentalis Least concern plants Deciduous conifers