DENDROLOGY

Detailed explanation-1: -trees are those that grow outwards by the addition of one concentric ring every year. These rings are known as annual rings. Since one ring in the stem of a tree indicates its age in years. It is timber obtained from this class of trees that is extensively used in engineering works.

Detailed explanation-2: -Exogenous trees, which comprise the great majority of modern trees (all conifers, and all broadleaf trees), grow by the addition of new wood outwards, immediately under the bark. Endogenous trees, mainly in the monocotyledons (e.g. palms), grow by addition of new material inwards.

Detailed explanation-3: -Trees which grow outwards and increase in bulk by the formation of successive annual rings are known as exogenous trees. Exogenous Trees Structure. Timber which is used for building engineering works, Is Mostly obtained from exogenous trees. Examples : Deodar, Kail, Sal, Teak, Shishum, Chir etc .

Detailed explanation-4: -Exogenous trees: These trees show distinctive annual rings when cross sectioned. Most of the timber that is suitable for engineering purposes is derived from these trees. The timber that is obtained from exogenous trees is further classified as: Soft wood: Soft wood is obtained from ever green trees.