Larches aredeciduousconifers in the genusLarix, of the familyPinaceae (subfamilyLaricoideae). Growing from 20 to 50 metres (65 to 165 feet) tall,[1] they are native to the cooler regions of the northern hemisphere, where they are found in lowland forests in the high latitudes, and high in mountains further south. Larches are among the dominant plants in theboreal forests ofSiberia andCanada. Although they areconifers, larches aredeciduous trees that lose theirneedles in the autumn.
The English name larch ultimately derives from the Latin "larigna", named after the ancient settlement of Larignum[dubious –discuss]. The story of its naming was preserved byVitruvius:
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.
The tallest species,Larix occidentalis, can reach 50 to 60 m (165 to 195 ft). Larch tree crowns are sparse, with the major branches horizontal; the second and third order branchlets are also ± horizontal in some species (e.g.L. gmelinii,L. kaempferi), or characteristicallypendulous in some other species (e.g.L. decidua,L. griffithii). Larch shoots are dimorphic, with leaves borne singly on long shoots typically 10 to 50 cm (4 to 20 in) long[2]: 47 and bearing severalbuds, and in dense clusters of 20–50 needles on short shoots[2] only 1–2 mm (1⁄32–3⁄32 in) long with only a single bud. Theleaves (light green) are needle-like,2 to 5 cm (3⁄4 to 2 in) long, slender (under1 cm or1⁄2 in wide). Larches are among the few deciduous conifers, which are usually evergreen. Other deciduous conifers include the golden larchPseudolarix amabilis, the dawn redwoodMetasequoia glyptostroboides, the Chinese swamp cypressGlyptostrobus pensilis and the bald cypresses in the genusTaxodium.
The male (pollen) cones are greenish-yellow to orange-yellowish and fall soon after pollination. The femalecones) of larches are erect, small,1–9 cm (1⁄2–3+1⁄2 in) long, green, red, or purple, ripening brown and woody- or leathery-textured 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 or1⁄2–1 in) with short bracts, with more southerly species tending to have longer cones (3–9 cm or1+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 root system is broad and deep and the bark is finely cracked and wrinkled in irregular plaques. The wood is bicoloured, with salmon-pinkheartwood and yellowish-whitesapwood.
Thechromosome number is 2n = 24, similar to that of most of the other species of the familyPinaceae.
The genusLarix is present in all the temperate-cold zones of thenorthern hemisphere, fromNorth America to northernSiberia passing throughEurope, mountainousChina andJapan. The larches are important forest trees ofRussia,Central Europe,United States andCanada. They require a cool and fairly humid climate and for this reason they are found in the mountains of the temperate zones, while in the northernmost boreal zones they are also found in the plains. Larch trees go further north than all, reaching in North America and Siberia thetundra and polar ice. The larches arepioneer species not very demanding towards thesoil and they are very long-lived trees. They live in pure or mixed forests together with other conifers or more rarely with broad-leaved trees.
The genusLarix belongs to the subfamilyLaricoideae, which also includes the Douglas-firs, genusPseudotsuga; the genusCathaya was also included in some older studies,[5] but is now considered closer toPinus andPicea.[6][3] 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[7] does not support this division, pointing instead to a genetic divide betweenOld World andNew 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;[8][9][10][11] there is some dispute over the position ofLarix 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.
Ten species and one natural hybrid of larch are accepted byPlants of the World Online (POWO),[12] following theconservative treatment in Farjon (2010);[5] several others are accepted by other authors, notably Rushforth,[1] and theFlora of China.[13] These are subdivided on the basis of the most recentphylogenetic investigations:
Larix gmelinii(Rupr.) Göpp. (syn.L. dahuricaTurcz. ex Trautv.,L. cajanderiMayr) – Dahurian larch. Plains of central and eastern Siberia.
Larix principis-rupprechtiiMayr – Prince Rupprecht's larch. Mountains of northeastern China (disputed; accepted by Rushforth[1] and many Chinese botanists;[14][15] treated as a variety ofL. gmelinii by POWO[12] despite its disjunct distribution and much larger cones).
Larix kaempferi(Lamb.) Carr. (syn.L. leptolepis(Siebold & Zucc.) Gordon & Glend.) – Japanese larch. Mountains of centralJapan.
Larix mastersianaRehder & E.H.Wilson – Masters' larch. Mountains of western China (northern Sichuan).
Larix griffithiiHook.f. (syn.L. griffithiana) – Sikkim larch. Mountains of the easternHimalayas, on the wet (high monsoon) southern slopes.
Larix himalaicaW.C.Cheng & L.K.Fu - Langtang larch. Mountains of the centralHimalayas (disputed; accepted by Rushforth[1] and theFlora of China;[13] treated as a variety ofL. potaninii by POWO[12] despite being geographically distant from it).
Larix kongboensisR.R.Mill - Kongbo larch. Mountains of southeastern Tibet, on the dry northern side of the Himalaya in theYarlung Tsangpo Grand Canyon area (disputed; accepted by theFlora of China;[13] treated as a synonym ofL. griffithii by POWO[12] despite its smaller cones and other distinct characters[13]).
Larix speciosaW.C.Cheng & Y.W.Law - Burmese larch. Mountains of southwesternChina (southwesternYunnan) and northeasternMyanmar (disputed; accepted by Rushforth[1] and theFlora of China;[13] treated as a variety ofL. griffithii by POWO[12] despite being geographically distant from it, and closer toL. potaninii in morphology[1]).
Most if not all of the species can behybridised in cultivation;[16] these hybrids are not discussed by POWO as they are not of natural occurrence. The hybridLarix ×marschlinsiiCoaz (syn.L. ×eurolepis), the Dunkeld larch, a spontaneous artificial hybridL. decidua ×L. kaempferi that arose more or less simultaneously in Switzerland and Scotland in 1901–1904,[17] is by far the best known, being of major importance inforestry in northern Europe.Larix ×pendula(Sol.) Salisb. (L. decidua ×L. laricina),[18] andLarix ×eurokurilensisRohm. (L. decidua ×L. gmelinii)[16] have also been named, but are rarely seen in cultivation.
Larches are associated with a number ofmycorrhizal fungal species, including some species which primarily or only associate with larch. One of the most prominent of these species is thelarch boleteSuillus grevillei.[19]
Larch is used as a food plant by thelarvae of a number ofLepidoptera species.
Larches are prone to thefungalcanker diseaseLachnellula ssp. (larch canker); this is particularly a problem on sites prone to late spring frosts, which cause minor injuries to the tree allowing entry to the fungal spores. InCanada, this disease was first detected in 1980 and is particularly harmful to an indigenous species larch, thetamarack, killing both young and mature trees.[20]Larches are also vulnerable toPhytophthora ramorum. In late 2009 the disease was first found inJapanese larch trees in theEnglish counties ofDevon,Cornwall andSomerset, and has since spread to the south-west of Scotland.[21][failed verification]In August 2010 the disease was found inJapanese larch trees in countiesWaterford andTipperary inIreland[22][failed verification] and in 2013 in theAfan Forest Park in southWales.[23]Laricifomes officinalis is another mushroom found inEurope,North America and northernAsia that causes internal wood rot. It is almost exclusive guest of thegen. Larix. Other diseases are given by mushrooms, fungal rusts, bacteria and insects.
Larchwood is valued for its tough,waterproof and durable qualities. Top qualityknot-free timber is in great demand for buildingyachts and other smallboats, 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.[24]
The hybrid Dunkeld larch is widely grown as atimber crop inNorthern 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]
Often, in Eurasianshamanism, the "world tree" is depicted as specifically a larch tree.[25] Planted on borders withbirch, both tree species were used in pagan cremations.[citation needed]
^Zhang, Jianwei; Xu, Huacheng (1995). Schmidt, Wyman C.; McDonald, Kathy J. (eds.).Silvics ofLarix principis-rupprechtii Mayr. in: Ecology and Management of Larix Forests GTR-INT-319: USDA Forest Service. pp. 227–230.{{cite book}}: CS1 maint: location (link)
^Li, Wenrong; Qi, Liwang; Han, Youzhi; Zhang, Jianwei (1995). Schmidt, Wyman C.; McDonald, Kathy J. (eds.).Distribution and Variation ofLarix principis-rupprechtii forest in Shanxi Province. in: Ecology and Management of Larix Forests GTR-INT-319: USDA Forest Service. pp. 360–364.{{cite book}}: CS1 maint: location (link)
^abVidaković, Mirko (1991).Conifers (English ed.). Croatia: Grafički Zavod Hrvatske. pp. 255–281.
^Candolle, Roger de; Burdet, Hervé M. (1983). "The correct name of the Dunkeld, or Hybrid, Larch".International Dendrology Society Yearbook.1982:67–68.
^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
^Stutley, Margaret (2003).Shamanism : An Introduction. London: Routledge, 2003.
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. MacmillanISBN0-333-49493-8.
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