Larix lyallii and Larix. occidentalis ( Larix sect. Multiseriales ) are similar morphologically and have similar geographic ranges. Just how closely the two species are related has not been determined, but they probably originated from a ommon ancestor resembling Larix. potaninii Batalin. Although the geographic ranges of the two species overlap considerably, elevational differences of 150 - 300 metres usually separate them. Some morphologically intermediate specimens have been collected from Washington and Montana[].

Common Name: Western Larch

General Information

Larix occidentalis is a deciduous tree with a short, conic crown; it can grow around 45 - 55 metres tall, exceptionally to 65 metres, with a trunk up to 200cm in diameter. Especially when growing in a forest, the trunk is usually branch-free over most of the tree's height[].
Larix occidentalis is one of the most valuable timber-producing species in western North America and is harvested in large quantities from the wild. It is also used locally as a source of food, medicine and materials.
Larix occidentalis is a widespread and common species with a broad distribution, ready recruitment of seedlings and regeneration power after disturbance. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

, ,

Range

Western N. America - British Columbia, Alberta, Washington, Oregon, Idaho, Montana

Habitat

Mountain valleys and lower slopes, often in swampy areas, usually on grey brown, well drained podzolic mountain soils, which are moderately acid and usually in mixed stands; at elevations from 500 - 2,100 metres[, , ].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	45.00 m
Growth Rate	Fast
Pollinators	Wind
Cultivation Status	Cultivated, Wild

Cultivation Details

Larix occidentalis is a very cold-hardy species, tolerating temperatures down to -30°c or lower when fully dormant. It is found in cold climates with cool summers and moist winters, the annual precipitation ranges from 450 - 875mm, much of which falls as snow[]
Prefers an open airy position in a light or gravelly well-drained soil[]. Plants are intolerant of badly drained soils, but they tolerate acid and infertile soils[]. Succeeds on rocky hill or mountain sides and slopes[]. A north or east aspect is more suitable than west or south[].
This is a very cold-hardy species when fully dormant, but on the whole the trees are a disappointment in mild maritime climates. They are often excited into premature growth by periods of mild weather in the winter and are then subject to damage by late frosts and cold winds. They also often suffer from canker and die-back[]. Good trees, however, can be very good and fast growing, often putting on new annual growth of 1 metre when young[].
Older trees develop a very thick bark, which protects them from forest fires[].
Hybridizes freely with other members of this genus[].
Open ground plants, 1 year x 1 year are the best for planting out, do not use container grown plants with spiralled roots[]. Plants transplant well, even when coming into growth in the spring[].
Plants in this genus are notably resistant to honey fungus[].

Edible Uses

A gum, or resin, is produced under the bark. It is a gum arabic substitute, very soluble in water, and is used as a thickening agent, stabilizer, emulsifier and for chewing[, ]. It exudes from the trunk and branches but commercially it is usually obtained by extraction from wood chips as a by-product of the lumber industry[, ].
The sap can be harvested in the spring and, when concentrated by boiling off much of the water, is made into a sweet syrup[, ].
A source of an edible manna[]. No further details are given, but this report probably refers to the gum mentioned above[].

Medicinal

The gum obtained from under the bark is used as a dressing in the treatment of cuts and bruises[].

An infusion of the bark has been used in the treatment of coughs, colds and tuberculosis[]. A decoction has been used as a wash on wounds and sores[].

The sap has been chewed in the treatment of a sore throat[].

The leaves and stems are antirheumatic, antiseptic, appetizer and blood purifier[]. A decoction has been used both internally and externally in the treatment of cancer, and is said to help an emaciated patient get better and gain weight[]. A decoction of the stem tips has been taken internally and also used as a soak on arthritic limbs and as a wash for cuts and sores[].

Agroforestry Uses:

An important natural pioneer species, it can be used in appropriate climates to restore woodland cover to degraded sites. It is a seral species readily colonizing open ground after disturbance, its initial numbers on a site can be
ery high, later to diminish as forest succession progressesp2124].

Other Uses

The resin from the wood has useful water soluble properties, and can be used for a variety of industrial products. It is especially applied in ink, paint and offset lithographic printing[].
A red powder can be made by heating the resin and then grinding it. This powder was mixed with fat and used as a cosmetic, or mixed with balsam poplar buds (Populus spp.) and used as a paint[, ].

The bark contains tannin[].

Wood - hard, strong, very heavy, very durable in the soil[, , ]. This is one of the most valuable timber-producing species in western North America, producing long straight knotless trunks; it a very important commercial crop in its native range[]. It is used for framing, cabinet making, construction, exterior and interior finishing work, railway ties, pilings, posts, fine veneer, pulp for the paper industry etc[, , , ].
A very good fuel, it is the preferred firewood.in parts of its range[].

Propagation

Seed - sow late winter in pots in a cold frame. One months cold stratification helps germination[]. It is best to give the seedlings light shade for the first year[]. As soon as they are large enough to handle, prick out the seedlings into individual pots. Although only a few centimetres tall, they can be planted out into their permanent positions in the summer providing you give them an effective weed-excluding mulch and preferably some winter protection for their first year. Otherwise grow them on in the cold frame for their first winter and plant them out in early summer of the following year. The seed remains viable for 3 years[]
If you are growing larger quantities of plants, you can sow the seed in an outdoor seedbed in late winter. Grow on the seedlings in the seedbed for a couple of years until they are ready to go into their permanent positions then plant them out during the winter.