Classifications of Trees

Trees are classified into two types, namely,

1. Endogenous
2. Exogenous

Endogenous

In the endogenous trees, a plant grows by the addition of new cells only at the tip or end, i.e., the trees grow inwards and fibrous mass is seen in their longitudinal section. Such trees show very little branches. The timber from these trees has very limited engineering applications. The examples of endogenous trees are bamboo, cane, palm, etc.

Exogenous

These trees increase in bulk by growing outwards and distinct consecutive rings are formed in the horizontal section of such trees. These rings are known as annual rings, because one such ring is added every year. Such trees grow bigger in diameter as well. The timber, which is mostly used for engineering purposes, belongs to this category.

The exogenous trees are further classified as

1. Conifers
2. Deciduous

Conifers: The conifers are known as evergreen trees. These trees bear cone-shaped fruits. These trees yield soft woods, which are generally light in colour, resinous, light in weight and weak.Deciduous: They are also known as broad leaf trees. The leaves of these trees fall in autumn and new ones appear in spring. Timber for engineering work is mostly derived from deciduous trees.

Trees can also be classified based on hardness into the following categories.

1. Hard wood
2. Soft wood

The soft wood forms a group of evergreen trees while the hard wood forms a group of broad leaf trees. Examples of soft woods are deodar, pine and other conifers. Hard woods include sal, mahogany, teak, oak, etc.