Larix (larch) description - The Gymnosperm Database

Larix

Miller 1754

Common names

Larch [English], mélèze, mélèze laricin [French:]; lärche [German]; larice [Italian]; Лиственница listvenitsa [Russian]; カラマツ karamatsu [Japanese], 落叶松属 [Chinese].

Taxonomic notes

Syn: Pinus Linnaeus p.p.; Abies A. L. de Jussieu (non Miller) (Dallimore et al. 1967).

Larix is the type genus of Pinaceae subfamily Laricoideae, which also includes Cathaya and Pseudotsuga (Frankis 1989, Farjon 1990, Li 1993).

There are 10 species in this treatment:

There is also one naturally-occurring nothospecies, Larix × czekanowskii Szafer (1913), the hybrid of L. gmelinii and L. sibirica. It is discussed under L. sibirica.

The European and North American species and varieties are generally agreed upon, while there is some debate about assigning specific, subspecific or varietal ranks to the Asian taxa. Such debate has principally involved L. sibirica and L. gmelinii, which together have a vast range including a small disjunct region (sometimes segregated from L. gmelinii as L. principis-rupprechtii) and very extensive zones of hybridization with each other and with intraspecific varieties (Milyutin and Vishnevetskaia 1995). The taxonomic uncertainties are partly due to the lack of a recent monographic treatment of Larix: the last were in 1930 (Ostenfeld and Syrach Larsen 1930) and, in a Russian paper not then readily available in the west, 1972 (Bobrov 1972). Moreover, there are political and linguistic problems involved in sorting out taxa native to remote areas of Russia and China.

Bobrov (1972) and LePage and Basinger (1995) suggest the following phylogenetic tree for Larix (modified):

Ancestral Larix
A.	Species with exserted bracts (Sect. Multiseriales Patschke; type L. griffithiana):
	1.	L. occidentalis & L. lyallii
	2.	L. potaninii, L. griffithiana, L. mastersiana
B.	Species with non-exserted bracts (Sect. Larix; type L. decidua):
	1.	L. laricina
	2.	L. decidua
	3.	L. sibirica
	4.	L. gmelinii, L. kaempferi

This was an attractive (and largely traditional) breakdown of the genus until the molecular folks got involved. Currently (2007.10.22) I have assembled five such studies:

Semerikov and Lascoux (1999), using isozymes, find a clear differentiation between New World and Old World larches.

Gernandt and Liston (1999), studying the nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) region in seven species of Larix and five of Pseudotsuga, consistently grouped the three North American species against a Eurasian suite including L. decidua, L. griffithii, L. sibirica and L. kaempferi. They rejected the hypothesis that L. decidua is derived from a short-bracted Eurasian lineage.

Wei and Wang (2003) used pollen cpDNA to split 12 species of Larix into three sister clades, one including North American species, and the other two comprised of the short-bracted and long-bracted species of Eurasia except that L. sibirica was in the long-bracted clade. Follow-up work (Wei and Wang 2004) using the nrDNA ITS confirmed the Eurasian-North American division of the genus.

Gros-Louis et al. (2005) went deeper, using genetic markers from the nuclear, chloroplast, and mitochondrial genomes to study ten species. They delineated three large groups: the North American, North Eurasian, and South Asian taxa. There was one significant ambiguity: L. sibirica was grouped with South Asian species on the cpDNA tree, but with its North Eurasian congeners on the mtDNA tree.

Based on these studies, I propose the following as a conceptual hypothesis of Larix phylogenetics:

phylogenetic tree

There is one noteworthy nothospecies, Larix × czekanowskii Szafer, the natural hybrid of L. gmelinii and L. sibirica.

Description

Deciduous trees with sparse, open crowns. Bark silver-gray to gray-brown on young trees, becoming reddish brown to brown, smooth initially, scaly to thickened and furrowed with age. Branches whorled; shoots strongly dimorphic; short (spur) shoots prominent on twigs 2 years or more old, each bearing leaves (needles), and often pollen cone, or seed cone; lateral long shoots (sylleptic branches) sometimes produced by current-year growth increments; leaf scars many. Buds rounded. Leaves in tufts of 10-60 on short (spur) shoots or borne singly on 1st-year long shoots, deciduous, ± flattened, with abaxial keel, sessile, base decurrent, sheath absent, apex pointed or rounded; resin canals 2. Pollen cones solitary, ovoid-cylindric, yellowish. Seed cones green, red or purple, maturing pale to dark brown in 4-7 months, persisting several years after seed release, erect, globose to ovoid, terminal on short shoots or lateral on 1-year-old long shoots, on a short leafy peduncle; scales persistent, circular to oblong-obovate, thin, tough and leathery, lacking apophysis and umbo; bracts included or exserted. Seeds winged; cotyledons 4-6. x=12" (Parker 1993, M.P. Frankis e-mail 1999.02.26).

Distribution and Ecology

Sect. Larix occurs in boreal circumpolar lowlands in Alaska, Canada and Russia, and at moderate to high altitudes in mountains south to NE USA, the Alps of Europe, Mongolia, NE China, N Korea and C Japan. Sect. Multiseriales occurs at high to very high altitudes in the Sino-Himalayan mountain system and the central Rocky Mts. (LePage and Basinger 1995, Schmidt and McDonald 1995).

Remarkable Specimens

The largest specimens are found in Larix occidentalis, by a wide margin. The oldest are found in Larix lyallii; the second-oldest is Larix decidua.

Ethnobotany

Some species of Larix are economically important for their hard, heavy, and decay-resistant wood (Parker 1993). Top quality knot-free wood ('boatskin larch') is in great demand for yacht building (M.P. Frankis e-mail 1999.02.26). Despite their popularity as garden trees, only a few have received any horticultural attention; some cultivars exist for the most commonly cultivated Old World larches, L. decidua Miller and L. kaempferi (Lambert) Carrière, but almost none for the North American species (Parker 1993). L. kaempferi is a popular bonsai subject in Japan (M.P. Frankis e-mail 1999.02.26).

All species have been used in dendrochronology, principally for dendroclimatic reconstruction, although there has been recent use of the North American and European taxa in ecological and ecophysiological research.

Observations

See the species descriptions.

Remarks

Larix was the Roman name for larch (Parker 1993).

Larches are widely used in forestry in cool-temperate to subarctic zones. L. sibirica has proved the most successful tree for use in Greenland, but L. decidua and L. kaempferi have received the greatest international attention. Most if not all hybrid combinations attempted have been successfully created; the hybrid L. decidua × L. kaempferi (L. × marschlinsii Coaz, syn. L. × eurolepis Henry nom. illeg.) is an important forest tree in Britain.

Citations

Farjon, Aljos. 1990. Pinaceae: drawings and descriptions of the genera Abies, Cedrus, Pseudolarix, Keteleeria, Nothotsuga, Tsuga, Cathaya, Pseudotsuga, Larix and Picea. Königstein: Koeltz Scientific Books.

Gernandt, D. S. and A. Liston (1999). Internal transcribed spacer region evolution in Larix and Pseudotsgua (Pinaceae). American Journal of Botany 86: 711-723.

Gros-Louis, M.-C., J. Bousquet, L. E. Pâques and N.e Isabel. 2005. Species-diagnostic markers in Larix spp. based on RAPDs and nuclear, cpDNA, and mtDNA gene sequences, and their phylogenetic implications. Tree Genetics & Genomes 1(2): 50-63.

Miller, P. 1754. The Gardener's Dictionary, abridged edition 4, vol. 1.

Semerikov, Vladimir L and Martin Lascoux. 1999. Genetic relationship among Eurasian and American Larix species based on allozymes. Heredity 83(1): 62-70. Available: www.nature.com/hdy/journal/v83/n1/full/6885310a.html, accessed 2007.10.22.

Szafer, W. 1913. Larix x czekanowskii hybr. nov. Kosmos 38:1281-1322 (p. 1297). Available: Śląska Biblioteka Cyfrowa (p. 458 of 870), accessed 2024.06.27.

Wei, X.-X. and Wang, X.-Q. 2003. Phylogenetic split of Larix: evidence from paternally inherited cpDNA trnT- trnF region. Plant Systematics and Evolution 239(1-2): 67-77.

Wei, X.-X. and Wang, X.-Q. 2004. Recolonization and radiation in Larix (Pinaceae): evidence from nuclear ribosomal DNA paralogues. Molecular Ecology 13(10): 3115-3123.