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Topics: Wood, Hardwood / Pages: 4 (817 words) / Published: Mar 25th, 2014
HARDWOOD
Hardwood is wood from angiosperm trees (more strictly speaking non-monocot angiosperm trees). It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.
Hardwood contrasts with softwood (which is from Gymnosperm trees). Hardwoods are not necessarily harder than softwoods. In both groups there is an enormous variation in actual wood hardness, with the range in density in hardwoods completely including that of softwoods; some hardwoods (e.g. balsa) are softer than most softwoods, while yews an example of a hard softwood.

CHARACTERISTICS

Hardwoods have a more complex structure than softwoods. The dominant feature separating "hardwoods" from softwoods is the presence of pores, or vessels. The vessels may show considerable variation in size, shape of perforation plates (simple, scalar form, reticulate, foraminate), and structure of cell wall, such as spiral thickenings.
Hardwoods are produced by angiosperm trees that reproduce by flowers, and have broad leaves. Many species are deciduous. Those of temperate regions lose their leaves every autumn as temperatures fall and are dormant in the winter, but those of tropical regions may shed their leaves in response to seasonal or sporadic periods of drought. Hardwood from deciduous species such as oak normally shows annual growth rings, but these may be absent in some tropical hardwoods.
Hardwoods are employed in a large range of applications including fuel, tools ,construction, boat building, furniture making, musical instruments, flooring, cooking, barrels, and manufacture of charcoal. Solid hardwood joinery tends to be expensive compared to softwood. In the past, tropical hardwoods were easily available but the supply of some species such as Burma teak, and mahogany is now becoming scarce

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