|This article contains content from Wikipedia|
An article on this subject has been nominated
for deletion at Wikipedia:
Wikipedia:Articles for deletion/
Current versions of the GNU FDL article on WP may contain information useful to the improvement of this article
It is estimated that there are approximately 180,000 wood-producing species on earth. Perhaps only 120,000 have been discovered and named. Cactus and palms are sometimes considered trees but do not produce woody tissue. Woods are generally divided into two categories: hardwoods and softwoods. Approximately 90% of the known species are considered are hardwoods and the remaining 10% are softwoods. The term s can be ambiguous, since many hardwoods are relatively soft, and some softwoods can be hard. A wood's relative "hardness" is measure by "Jenka " units, which characterize the density or hardness of a wood. Some of the hardest woods in the world include teak and queen ebony. Queen ebony is extremely rare and only grows on a northern island in the Solomon Island chain. There it is confined to perhaps 10 acres of swampy land. Both woods are used extensively in the shipbuilding industry because of their resistance to marine borers.
Wood colors and characteristics Edit
Virtually every color is represented by some species of wood. The natural coloration being affected by both soil characteristics and genetics. Until recently, most woods were identified by physical characteristics such as specific gravity (does it float in water or sink), smell, taste, weight, and fluorescence. Some woods, when exposed to black light (UV) glow. In recent years DNA testing was adopted and is much more speedy and accurate.
Wood research libraries and collections Edit
Collections of exotic woods for research and reference are kept in xylariums. The word xylum is derived from the Latin, meaning "wood". Two of the largest xylariums in the world are located at the Forest Products Labs, a division of the U.S. Dept of Agriculture on the campus of the University of Wisconsin in Madison, Wisconsin. The collection is the result of an accumulation from private, university and governmental agencies. The other major xylarium is located in Great Britain, outside London in the Kew Gardens.
Wenge and zebrawood are exotic tropical woods that are considered endangered or threatened in their natural ranges. Wenge has a distinctive dark hue and fine, black veins. Zebrawood displays characteristic light and dark variations, giving a pinstriped look. Bamboo is actually a grass, not a wood, and since it is among the fastest-growing plants on the planet, it is naturally self-renewing. American red gum (also called sweetgum) is one of the most common hardwoods in the eastern US, and also occurs naturally in Central America and Mexico. Prized for its uniquely irregular interlocked grain and variable patterns of coloration, it is not considered a threatened species.
Reconstituted wood Edit
Reconstituted woods are an engineered product. They use man- made veneers which are created from less rare (and non-threatened) wood species grown in rapidly-renewable, sustainable plantations; this lessens their environmental impact. 
See also Edit
- ↑ from "Guide to The Useful Woods of the World-Vo. I $ II by Curtis
- ↑ 2.0 2.1 [http://www.showplacewood.com/litlibrary/downloads/About.SWP.exotics.pdf Exotics]