Larix occidentalis

Sherrard, E. C., Ethyl alcohol from western larch—larix occidentalis, nuttal. Industrial Engineering Chemistry 1922, 14(10), 948-949. 

Arabinogalactan occurs as a white to yellow-white, coarse or fine powder. It is the dried water extract from the wood of the larch trees Larix occidentalis and Larix laricina (Fam. Pinaceae). It is a highly branched polysaccharide that has a molecular weight of 15,000 to 60,000 daltons and is composed of galactose units and arabinose units in the approximate ratio of 6 1. It is freely dispersible in hot or cold water. It is insoluble in alcohol. 

Koch/Tamarack Larix occidentalis Nutt./ Western larch Libocedrus decurrens Torn/ Incense cedar Picea engelmanni Parry ex Engelm./Engelman spruce Picea glauca (Moench) Voss/ White spruce... 

Larch wood Larix occidentalis) Decomposed Douglas-fir Pseudotsuga menzeisii) Ponderosa pine Pinus ponderosa) Aspen... 

Yellow birch (Betula allerghaniensis Britton) 21 Western larch (Larix occidentalis Nutt.) 27... 

The water-extractable arabinogalactans are most abundant in the larches (Larix spp.). The most extensively studied has been that of the heartwood of the western larch Larix occidentalis). The source, production, properties, and potential uses of this polysaccharide are reviewed in Chap. 10.2.2. 

It has been reported that the ratio of galatose to arabinose in the arabinogalactan of Larix occidentalis increases and that the number-average molecular weight of the polymer decreases with increasing age of the wood (67, 154). 

Churms S C, Merrifield E H, Stephen A M 1978 Regularity within the molecular structure of arabinogalactan from Western larch (Larix occidentalis). Carbohyd Res 64 C1-C2... 

One way to assure low raw material costs is to have multiple use of the material. If wood chips, sawdust, or bark is to be extracted, the residue should be useful for another purpose. Examples of this approach are 1) Isolation of arabinogalac-tan gum from western larch Larix occidentalis) heartwood chips followed by kraft pulping of the extracted chips 2) isolation of mimosa tannins from bark of trees in which the peeled wood Acacia sp.) serves as raw material for chemical cellulose production (South Africa) and 3) tall oil separation from the concentrated black liquor derived from kraft pulping of southern pines. In each of these cases the brunt of the raw material cost is carried by some product other than the extractive. Assurance of low raw material costs virtually dictates extractive isolation and processing ancillary to a forest products processing plant. 

An industrial source of larch gum is the western larch Larix occidentalis, Pinaceae), native to the mountains of western North America, whose wood contains up to 35% galactoarabans these are... 

Carlson, C.E. 1994. Germination and early growth of western larch (Larix occidentalis), alpine larch (Larix lyallii), and their reciprocal hybrids. Can. J. For. Res. 24 911-916. 

Carlson, C.E., R.G. Gates and S.G. Spencer. 1991. Foliar terpenes of a putative hybrid swarm (Larix occidentalis Nutt. X L. lyallii Pari.) in western Montana. Can. J. For. Res. 21 876-881. 

Owens, J.N. and M. Molder. 1979a. Bud development in Larix occidentalis. II. Cone differentiation and early development. Can. J. Bot. 57 1557-1572. 

Owens, J.N., S.J. Morris and G.L. Catalano. 1994. How the pollination mechanism and prezygotic and postzygotic events affect seed production in Larix occidentalis. Can. J. For. Res. 24 917-927. 

Rehfeldt, G.E. 1982. Differentiation of Larix occidentalis populations from the Northern Rocky Mountains. Silvae Genet. 31 13-19. 

Rehfeldt, G.E. 1992. Breeding strategies for Larix occidentalis adaptations to the biotic and abiotic environment in relation to improving growth. Can. J. For. Res. 22 5-13. 

Rehfeldt, G.E. 1995b. Genetic variation, climate models and the ecological genetics of Larix occidentalis. For. Ecol. Manag. 78 21-37. 

Schmidt, W.C. and R.C. Shearer. 1990. Larix occidentalis Nutt. - western larch. Pp. 160-172 in R.M. Burns and B.H. Honkala (technical coordinators), Silvics of North America, Vol. 1. USDA Agriculture Handbook 654. 

Shearer, R.C. and C.E. Carlson. 1993. Barriers to germination of Larix occidentalis and Larix lyallii seeds. Pp. 127-132 in Edwards DGW, (ed.) Dormancy and barriers to germination. Proceedings. International Symposium of lUFRO Project Group P2.04-00 (Seed Problems) 1991 April 23-26 Victoria, BC Forestry Canada, Pacific Forestry Centre. 

Shearer, R.C., M.U. Stoehr, J.E. Webber and S.D. Ross. 1999. Seed cone production enhanced by injecting 38-year-old Larix occidentalis Nutt, with GA4/7. New For. 18 289-300. 

Wang, C.W. 1971. The early growth of Larix occidentalis x L. leptolepis hybrids. University of Idaho College of Forestry, Wildlife and Range Sciences Station Note No. 17.4 pp. 

North american larches (Larix lyalli, Larix occidentalis, Larix laricind) Douglas-Fir (Pseudotsuga menziesii Lodgepole pine (Pinus contortd)... 

Definition Poiysaccharide extracted from Western iarch wood, Larix occidentalis, having gaiactose and arabinose units in approx, ratio 6 1 Properties Lt. yei. to amber very vise, iiq. baisam pine odor soi. in water m.p. > 200 C (dec.)... 

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