Subalpine larch male fall foliage and cone (strobilus)
Larches are deciduous conifers in the genus Larix, of the family Pinaceae (subfamily Laricoideae). Growing from 20 to 45 metres (65 to 150 feet) tall, they are native to much of the cooler temperate northern hemisphere, on lowlands in the north and high on mountains further south. Larches are among the dominant plants in the boreal forests of Siberia and Canada. Although they are conifers, larches are deciduous trees that lose their needles in the autumn.
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.
Larix lyallii in autumn
Description and distribution-The tallest species, Larix occidentalis, can reach 50 to 60 m (165 to 195 ft). The larch's tree crown is sparse and the branches are brought horizontal to the stem, even if some species have them characteristically pendulous. Larch shoots are dimorphic, with leaves borne singly on long shoots typically 10 to 50 cm (4 to 20 in) long: 47 and bearing several buds, and in dense clusters of 20–50 needles on short shoots only 1–2 mm (1⁄32–3⁄32 in) long with only a single bud. The leaves (light green) are needle-like, 2 to 5 cm (3⁄4 to 2 in) long, slender (under 1 cm or 1⁄2 in wide). Larches are among the few deciduous conifers, which are usually evergreen. Other deciduous conifers include the golden larch Pseudolarix amabilis, the dawn redwood Metasequoia glyptostroboides, the Chinese swamp cypress Glyptostrobus pensilis and the bald cypresses in the genus Taxodium. 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, the root system are 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.
Larix occidentalis (Navaho Ridge, Washington state, USA)
The genus Larix is present in all the temperate-cold zones of the northern hemisphere, from North America to northern Siberia passing through Europe, mountainous China and Japan. The larches are important forest trees of Russia, Central Europe, United States and Canada. 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 ones they are also found in the plain. At gen. Larix belong to the trees that go further north than all, reaching in the North America and Siberia the tundra and polar ice. The larches are pioneer species not very demanding towards the soil and they are very long-lived trees. They live in pure or mixed forests together with other conifers or more rarely broad-leaved trees.
There are eleven (or ten, see L. czekanowskii) accepted species of larch subdivided on the basis of the most recent phylogenetic investigations.
Hybrids-
Most if not all of the species can be hybridised in cultivation. Currently-accepted hybrids are.
Larix × lubarskii Sukaczev
Larix × maritima Sukaczev
Larix × polonica Racib.
A well-known hybrid, the Dunkeld larch Larix × marschlinsii, arose more or less simultaneously in Switzerland and Scotland when L. decidua and L. kaempferi hybridised when planted together, is still treated as unresolved. Larix × stenophylla Sukaczev is another probable hybrid still unresolved.
Larch is used as a food plant by the larvae of a number of Lepidoptera species — see list of Lepidoptera that feed on larches.
Larix laricina in autumn (Vermont)
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.
Diseases Larches are prone to the fungal canker disease Lachnellula 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. In Canada, this disease was first detected in 1980 and is particularly harmful to an indigenous species larch, the tamarack, killing both young and mature trees. Larches are also vulnerable to Phytophthora ramorum. In late 2009 the disease was first found in Japanese larch trees in the English counties of Devon, Cornwall and Somerset, and has since spread to the south-west of Scotland.[8][failed verification] In August 2010 the disease was found in Japanese larch trees in counties Waterford and Tipperary in Ireland[failed verification] and in 2013 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 guest of the gen. Larix. Other diseases are given by mushrooms, fungal rusts, bacteria and insects.
Male (above) and female (below right) cones of Japanese larch emerging in spring
Uses Larch wood is valued for its tough, 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.
The hybrid Dunkeld larch is widely grown as a timber crop in 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.
In Central Europe larch is viewed as one of the best wood materials for the building of residences.[citation needed] Larches are often used in bonsai culture, where their knobby bark, small needles, fresh spring foliage, and – especially – autumn colour are appreciated.[citation needed] European larch, Japanese larch, and Tamarack larch are the species most commonly trained as bonsai. The edible larch boletes grow in symbiotic association with larch trees.
Often, in Eurasian shamanism, the "world tree" is depicted as specifically a larch tree. Planted on borders with birch, both tree species were used in pagan cremations.[citation needed]
