Larch - WikiHQ

Larches are deciduous conifers in the genus Larix, of the family Pinaceae. Growing to as much as tall, they are native to the cooler regions of the Northern Hemisphere. They grow in lowland forests in the far north, and high in mountains further south. Larches are among the dominant plants in the boreal forests of Siberia and Canada, making them the most abundant genus of trees on earth. Larch wood is tough and relatively durable; it is used in boatbuilding, cladding, decking, garden furniture, fencing, and construction. Products extracted from larch include arabinogalactan (larch gum), rosin, turpentine, and an essential oil.

Etymology

The English name larch was recorded in 1548 by the botanist William Turner. It derives from the German , in turn from the Middle High German , which is conjectured to derive from an unrecorded Old High German name for the tree, *larihha. That derives from the Latin name of the tree, Larix. The Latin name probably was borrowed from a Gaulish language spoken in the Alps. Larch wood is resinous. The bark of young trees is smooth; that of older trees is thick and scaly. Larches are among the few deciduous conifers, which are usually evergreen.

File:Larix occidentalis Abies lasiocarpa.jpg|Larix occidentalis can reach in height. Oregon

File:Larix decidua leaf dimorphism singly or in dense clusters on same tree.jpg|Larch shoots (here Larix decidua) are dimorphic, with long shoots with widely spaced needles, and short shoots with dense clusters of leaves.

File:10 31 2008 Stand of Tamarack.jpg|Larches, like this Larix laricina in Vermont, are deciduous, dropping their leaves in autumn.

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Cones

The male (pollen) cones are small, on the ends of shoots that die after pollination.

File:Larch distribution.svg|Worldwide distribution of genus Larix. The circumboreal and Sino-Himalayan groups are clades.

File:Nature in Khanty-Mansiya.jpg|Larix sibirica in Khanty-Mansiya, Russia

File:Raven Ridge - Flickr - brewbooks (2).jpg|Larix lyallii forest in Washington state

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Evolution

External phylogeny

The genus Larix belongs to the subfamily Laricoideae, which includes the Douglas firs, genus Pseudotsuga. The genus Cathaya was included in some older studies, but based on transcriptome analysis, is now considered closer to Pinus and Picea. The split of Larix from Pseudotsuga occurred about 45 million years ago.

Taxonomy and internal phylogeny

thumb|upright=0.6|[[Larix griffithii in Bhutan, a species with long bracts. This attribute had been thought to define a group within the genus. In the 20th century, cone bract length was used to divide the larches into two sections (sect. Larix with short bracts, and sect. Multiserialis with long bracts), but genetic evidence does not support this division, indicating instead that the cone and bract size are merely adaptations to climatic conditions.

Late 20th century and early 21st century genetic studies proposed three groups within the genus, with a primary division into North American and Eurasian species, and a secondary division of the Eurasian into northern short-bracted species and southern long-bracted species; there was dispute over the position of Larix sibirica, a short-bracted species which is placed in the short-bracted group by some of the studies and the long-bracted group by others. following the conservative treatment in Farjon (2010);

However, a 2025 study by Qiu and colleagues cast doubt on the species circumscriptions accepted by Farjon and the POWO; these hybrids are not discussed by POWO as they are not of natural occurrence. Larix × marschlinsii (syn. L. × eurolepis), the Dunkeld larch, a hybrid of L. decidua × L. kaempferi, is by far the best known: it is of major importance in forestry in northern Europe. It arose more or less simultaneously in Switzerland and Scotland in 1901–1904. Other named hybrids include Larix × pendula (L. decidua × L. laricina), and Larix × eurokurilensis (L. decidua × L. gmelinii). Larch is used as a food plant by the larvae of moths such as the larch pug, Eupithecia lariciata.

The large larch bark beetle, Ips cembrae, can be harmful to already-weakened larch trees, but is in general a less serious threat than a related species, the spruce bark beetle Ips typographus, is to spruces.

File:Suill.grev.jpg|The larch bolete Suillus grevillei, a mycorrhizal mushroom, only grows under larches.

File:Lärchenborkenkäfer Draufsicht.png|Adult large larch bark beetle, Ips cembrae

File:Lärchenborkenkäfer Brutbild.JPG|Galleries of Ips cembrae under the bark

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Diseases

Larches are prone to the fungal canker disease Lachnellula spp. (larch canker); this is a problem when late spring frosts cause minor injuries to the tree, allowing entry to the fungal spores. In Canada, this disease was first detected in 1980; it kills Larix laricina of any age.

Larches are vulnerable to Phytophthora ramorum. In 2013 the disease appeared in the Afan Forest Park in south Wales.

Laricifomes officinalis is another mushroom found in Europe, North America and northern Asia that causes internal wood rot. It is almost exclusive to the genus Larix. Other diseases are caused by mushrooms, fungal rusts, and bacteria.

Uses

Larch timber has many uses, including boatbuilding, exterior cladding, and interior panelling. Outdoor uses include fencing, gates, decking, garden furniture, and playground equipment. Since the heartwood is strong, durable, and available in large sizes, it is used for structures such as agricultural buildings. The Savill Building in Windsor Great Park has a timber roof shell made of many relatively thin laths, interlocking to provide strength. The wood is used, too, as fuel in industrial biomass energy plants. The bark used as a mulch in horticulture. Arabinogalactan, used in animal feed, cosmetics, and medicines, is extracted from heartwood. Larch trees can be tapped for liquid to be distilled into Venice turpentine. The tree yields rosin for violin bows and an essential oil used in aromatherapy. European Standard EN 350-2 lists larch as slightly to moderately durable.

Dunkeld larch is widely grown as its timber is durable and strong, and the tree tolerates poor weather better than non-hybrid larches.

File:Concordia molen Ede stijl korbeel.jpg|Larch wood in use to restore the Concordia mill, Netherlands

File:Saville Building roof interior long.jpg|The roof shell of the Savill Building is made of interlocking larch laths.

More recently, the Monty Python comedy troupe filmed a sketch with three schoolboys shown slides of the larch and asked which trees they were able to identify.

File:Larch, from The Park and the Forest James Duffield Harding 1841.jpg|Larch, from The Park and the Forest, James Duffield Harding, 1841

File:James Ward - Larch Tree - Google Art Project.jpg|Larch tree pencil drawing, James Ward, before 1859

File:Franz Marc, Lärchenbäumchen.jpg|Larch sapling, Franz Marc, 1908

File:Berry Lärchen im Schnee.jpeg|Larch in first snow, Peter Robert Berry, 1914

File:Lovis Corinth Lärche am Waldsee 1923.jpg|Larch by forest lake, Lovis Corinth, 1923

File:Lovis Corinth Walchensee mit Lärche 1923.jpg|Walchensee with fountain, Lovis Corinth, 1923

File:Stamp of Russia 2013 No 1684 Larix cajanderi.jpg|Russian 15 rouble stamp, 2013, Larix cajanderi

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References

External links

Friedman, William (Ned). "Larch cones in spring". Posts from the Collection, Arnold Arboretum of Harvard University, 2 April 2016.
Rose, Nancy. "Not All Conifers are Evergreen". Arnold Arboretum of Harvard University, 6 January 2016.
"Snow Scenes, winter, larches 1977". Library Featured Images, Arnold Arboretum of Harvard University, 21 November 2019.

Etymology

Cones

Evolution

External phylogeny

Taxonomy and internal phylogeny

Diseases

Uses

References

Further reading

External links