Larch

Larch
Larix lyallii in autumn near Sprite Lake in Washington State, US
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Gymnospermae
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	Pinaceae
Subfamily:	Laricoideae
Genus:	Larix Mill.
Type species
Larix decidua Mill.
Species
About 10–11; see text

Larches are

Etymology

The English name larch ultimately derives from the Latin "larigna", named after the ancient settlement of Larignum. The story of its naming was preserved by Vitruvius:

It is worth while to know how this wood was discovered. The divine Caesar, being with his army in the neighbourhood of the Alps, and having ordered the towns to furnish supplies, the inhabitants of a fortified stronghold there, called Larignum, trusting in the natural strength of their defences, refused to obey his command. So the general ordered his forces to the assault. In front of the gate of this stronghold there was a tower, made of beams of this wood laid in alternating directions at right angles to each other, like a funeral pyre, and built high, so that they could drive off an attacking party by throwing stakes and stones from the top. When it was observed that they had no other missiles than stakes, and that these could not be hurled very far from the wall on account of the weight, orders were given to approach and to throw bundles of brushwood and lighted torches at this outwork. These the soldiers soon got together.

The flames soon kindled the brushwood which lay about that wooden structure and, rising towards heaven, made everybody think that the whole pile had fallen. But when the fire had burned itself out and subsided, and the tower appeared to view entirely uninjured, Caesar in amazement gave orders that they should be surrounded with a palisade, built beyond the range of missiles. So the townspeople were frightened into surrendering, and were then asked where that wood came from which was not harmed by fire. They pointed to trees of the kind under discussion, of which there are very great numbers in that vicinity. And so, as that stronghold was called Larignum, the wood was called larch.

— "Book II" . Ten Books on Architecture – via Wikisource.

Description and distribution

The tallest species,

The male flowers (small cones) are orange-yellowish and fall after pollination. The female flowers (or cones) of larches are erect, small, 1–9 cm (1⁄2–3+1⁄2 in) long, green or purple, brown in ripening and lignify (called now strobilus) 5–8 months after pollination; in about half the species the bract scales are long and visible, and in the others, short and hidden between the seed scales. Those native to northern regions have small cones (1–3 cm or 1⁄2–1 in) with short bracts, with more southerly species tending to have longer cones (3–9 cm or 1+1⁄4–3+1⁄2 in), often with exserted bracts, with the longest cones and bracts produced by the southernmost species, in the Himalayas. The seeds are winged. The larches are streamlined trees,^{[clarification needed]} the root system is broad and deep and the bark is finely cracked and wrinkled in irregular plaques. The wood is bicolor, with salmon pink heartwood and yellowish white sapwood.

The chromosome number is 2n = 24, similar to that of most of the other trees of the family Pinaceae.

The genus Larix is present in all the temperate-cold zones of the

In the past, the cone bract length was often used to divide the larches into two sections (sect. Larix with short bracts, and sect. Multiserialis with long bracts), but genetic evidence[5] does not support this division, pointing instead to a genetic divide between Old World and New World species, with the cone and bract size being merely adaptations to climatic conditions. More recent genetic studies have 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;^[6][7][8][9] there is some 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. The genus Larix belongs to the subfamily Laricoideae, which also includes the genera Pseudotsuga and Cathaya.

There are ten accepted species of larch and one accepted hybrid, subdivided on the basis of the most recent phylogenetic investigations:^[10]

North American species

• Larix laricina (Du Roi) K. Koch – Tamarack or American larch. Parts of Alaska and throughout Canada and the northern United States from the eastern Rocky Mountains to the Atlantic shore.
• Larix lyallii Parl. – Subalpine larch. Mountains of northwest United States and southwest Canada, at very high altitude.
• Larix occidentalis Nutt. – Western larch. Mountains of northwest United States and southwest Canada, at lower altitudes (Pacific Northwest
  ).

• Larix decidua Mill. (syn. L. europaea D.C.) – European larch; mountains of central Europe
• Larix sibirica Ledeb. – Siberian larch. Plains of western Siberia
• Larix gmelinii (Rupr.) Kuzen. (syn. L. dahurica) – Dahurian larch; Plains of central and eastern Siberia
• Larix kaempferi (Lamb.) Carr. (syn. L. leptolepis) – Japanese larch; Mountains of central Japan
• Larix × czekanowskii Szafer – an accepted hybrid between L. gmelinii and L. sibirica.^[10]

Southern Euroasiatic species with long bracts

• Larix potaninii Batalin – Chinese larch. Mountains of southwestern China (Sichuan, northern Yunnan).
• Larix mastersiana Rehder & E.H.Wilson – Masters' larch. Mountains of western China.
• Larix griffithii Hook.f. (syn. L. griffithiana) – Himalayan larch. Mountains of the eastern Himalayas.

Hybrids

Most if not all of the species can be hybridised in cultivation.^{[citation needed]}

Selected hybrids include:^[10]

• Larix gmelinii var. olgensis syn. Larix lubarskii Sukaczev
• Larix gmelinii var. gmelinii syn. Larix maritima Sukaczev
• Latrix decidua var polonica syn. Larix polonica Racib.
• Larix gmelinii var. principis-rupprechtii (Mayr) Pilg.

The hybrid, Larix × marschlinsii, the Dunkeld larch, is an artificial hybrid L. decidua × L. sibirica^[10] that arose more or less simultaneously in Switzerland and Scotland.^{[citation needed]}

Larix × stenophylla Sukaczev is another probable hybrid still unresolved.^{[citation needed]}

Larch is used as a food plant by the larvae of a number of Lepidoptera species.

Ecology

Larches are associated with a number of mycorrhizal fungal species, including some species which primarily or only associate with larch. One of the most prominent of these species is the larch bolete Suillus grevillei.^[11]

Diseases

Larches are prone to the

Japanese larch trees in the English counties of Devon, Cornwall and Somerset, and has since spread to the south-west of Scotland.^{[13][failed verification}

] In August 2010 the disease was found in

Japanese larch trees in counties Waterford and Tipperary in Ireland^{[14][failed verification]} and in 2013 in the Afan Forest Park in south Wales.^[15]

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

Uses

Larch

waterproof and durable qualities. Top quality knot-free timber is in great demand for building yachts and other small boats, for exterior cladding of buildings, and interior paneling. The timber is somewhat resistant to rot when in contact with the ground, and historically was used as posts and in fencing. However, European Standard EN 350-2 lists larch as slightly to moderately durable; this would make it unsuitable for ground contact use without preservative in temperate climates, and would give it a limited life as external cladding without coatings.^[16]

The hybrid Dunkeld larch is widely grown as a

Northern Europe

, valued for its fast growth and disease resistance.

Larch on oak was the traditional construction method for Scottish fishing boats in the 19th century.^[citation needed]

Larch has also been used in herbal medicine; see Bach flower remedies and Arabinogalactan for details.

Often, in Eurasian shamanism, the "world tree" is depicted as specifically a larch tree.^[17] Planted on borders with birch, both tree species were used in pagan cremations.^{[citation needed]}

Gallery

• 
  Larix laricina in autumn (Vermont)
• 
  Larix occidentalis

  (Navaho Ridge, Washington state, US)
• 
  Male (above) and female (below right) cones of

  Japanese larch

  emerging in spring
• 
  Subalpine larch male fall foliage and cone (strobilus

  )

References

1. ISBN 3-444-70130-6
   .
2. ^
   ISBN 978-0-521-70772-5
   .
3. S2CID 232282918
   .
4. doi:10.6084/m9.figshare.14547354.v1
   .
5. PMID 10330075
   .
6. S2CID 22249365
   .
7. S2CID 39213284
   .
8. S2CID 11329782
   .
9. S2CID 44245647
   .
10. ^ ^{a b c d} "Larix Mill". Plants of the World Online. London: Royal Botanic Gardens, Kew. Retrieved 11 February 2024.
11. doi:10.1016/j.fldmyc.2017.07.010
    .
12. ^ European larch canker Natural Resources Canada, accessed 23 April 2021
13. ^ "Find a specific tree pest or disease". GOV.UK.
14. ^ "Department of Agriculture, Food and the Marine". www.gov.ie.
15. ^ "Thousands of Afan Forest trees planted after infected larch". BBC. 21 February 2015. Retrieved 23 February 2015.
16. ^ European Standard EN 350-2 (1994); Durability of Wood and Wood-based Products – Natural Durability of Solid Wood: Guide to natural durability and treatability of selected wood species of importance in Europe
17. ^ Stutley, Margaret (2003). Shamanism : An Introduction. London: Routledge, 2003.

Further reading

• Earle, Christopher J., ed. (2011). "Larix (larch) description". The Gymnosperm Database.
• Givnish, Thomas J. (2002). "Adaptive significance of evergreen vs. deciduous leaves: solving the triple paradox" (PDF). Silva Fennica. 36 (3): 703–743.
  doi:10.14214/sf.535. Archived
  (PDF) from the original on 7 April 2014. The larch paradox—Finally, let us turn to one last, enduring ecological paradox: the deciduous habit of larches (Larix) at high latitudes in nutrient-poor peatlands in the northern hemisphere, where evergreen plants are expected to dominate and often do. Quote from p. 729.
• Phillips, D. H., & Burdekin, D. A. (1992). Diseases of Forest and Ornamental Trees. Macmillan
  ISBN 0-333-49493-8
  .

External links

Wikimedia Commons has media related to Larix.

• Larix images at the Arnold Arboretum of Harvard University Plant Image Database
• Friedman, William (Ned). "Larch cones in spring". Posts from the Collection, Arnold Arboretum of Harvard University, 2 April 2016. Accessed 26 May 2020.
• Rose, Nancy. "Not All Conifers are Evergreen". Arnold Arboretum of Harvard University website, 6 January 2016. Accessed 26 May 2020.
• "Snow Scenes, winter, larches 1977". Library Featured Images, Arnold Arboretum of Harvard University website, 21 November 2019. Accessed 26 May 2020.
• "Gymnosperm Database - Larix ssp".
• Eichhorn, Markus (August 2011). "The Larch". Test Tube. Brady Haran for the University of Nottingham.
• "Larch" . The New Student's Reference Work . 1914.