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: Sub-Alpine Larch

General Information

Larix lyallii is a deciduous tree with a sparse, conic crown; it can grow up to 25 metres tall with a trunk up to 120cm in diameter[].
Because of its restricted distribution and because it grows at the timberline, this species has no commercial importance. It is harvested from the wild for local use as a food and source of materials.
The extreme habitat for tree growth that Larix lyallii occupies ensures that it will not be exploited for timber. It is naturally resilient against stochastic events causing damage or death and although recruitment is episodic, it appears to be sufficient to maintain the species across its range. 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, Idaho, Montana

Habitat

Talus slopes in the sub-alpine to alpine zones, often on north-facing slopes where snow lies until late in the season; at elevations from 1,800 - 2,400 metres[, ].

Properties

Conservation Status	Least Concern
Edibility Rating
Other Uses Rating
Habit	Deciduous Tree
Height	25.00 m
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

Larix lyallii is a very cold-hardy plant that succeeds up to the tree line and in subalpine regions with their short, cool summers ans long, snowy winters. When fully dormant it can tolerate temperatures down to -45°c or lower, but the trees can be excited into premature growth in mild maritime climates by mild spells during the winter and they are then very subject to damage by late frosts and cold winds[, ].
Prefers an open airy position in a light or gravelly well-drained soil[]. Intolerant of badly drained soils, but tolerates 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[].
Plants are not very successful in mild maritime climates, they have been tried on many occasion in Britains but have failed to make a satisfactory tree[, ]. A specimen at the Hillier Arboretum was 4.5 metres tall in 1970 and suffered frost damage each year[].
This species is impossible to grow in lowland Britain, though it should succeed above a height of 300 metres in the eastern Scottish Highlands[]. Growth is normally slow in Britain with average height increases of less than 30cm per year[].
Hybridizes freely with other members of this genus[].
Closely related to Larix occidentalis[].
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

The shoot-tips are used as a flavouring in soups[].

Medicinal

None known

Agroforestry Uses:

A pioneer species in its native range, it established in avalanche chutes and can minimize the destructive impact of snow avalanches better than most other conifers[].

Other Uses

The bark contains tannin[].

Wood - strong, heavy, hard, coarse-grained and durable[, ]. The wood is of the same high quality as other Larix species, but trees are not commercially exploited because of their remote locations and the fact that they are often stunted by the extreme environmental conditions[].

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.