Wood Is hard, fibrous, lignified structural tissue produced as secondary yxlem in the stems of woody plants, notably trees but also shrubs. In a living tree it conducts water and nutrients to the leaves and other growing tissues, and acts in a support function, enabling plants to reach large sizes. Wood may also refer to other plant materials and tissues with comparable properties.

Artists can use wood to create delicate sculptures.

People have used wood for millennia for many purposes. One of its primary uses is as fuel. It is also used as for making artworks, furnture,tools and weapons, and as a construction material.

Formation

A tree increases in diameter by the formation, between the old wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. Where there are clear seasons, this can happen in a discrete pattern, leading to what is known as growth rings, as can be seen on the end of a log. If these seasons are annual these growth rings are annual rings. Where there is no seasonal difference growth rings are likely to be indistinct or absent.

Within a growth ring it may be possible to see two parts. The part nearest the center of the tree is more open textured and almost invariably lighter in colour than that near the outer portion of the ring.

The inner portion is formed early in the season, when growth is comparatively rapid; it is known as early wood or spring wood. The outer portion is the late wood or summer wood, being produced in the summer In white pines there is not much contrast in the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work.

In hard pines, on the other hand, the late wood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored early wood. In ring-porous woods each season's growth is always well defined, because the large pores of the spring abut on the denser tissue of the fall before. In the diffuse-porous woods, the demarcation between rings is not always so clear and in some cases is almost (if not entirely) invisible to the unaided eye.