(a) Pith: The innermost central component or middle of the tree is referred to as the pith or medulla. Having different sizes from tree to tree. It mainly represents the decayed part of the wood hence does not give any strength to it. (b) Heartwood: The inner annual rings surrounding the pith is known as heartwood. It is likewise darkish in color as a result does now no longer take an energetic component withinside the increase of the tree. But timber has electricity due to this component.
(c) Sapwood: The outer annual earrings among the heartwood and the cambium layer is called sapwood. Also known as alburnum. It’s color generally light which indicates that through this layer trees take their food and nutrients from the soil. It does not give any strength to it.
(d)Cambium layer: Thin layer of sap between sapwood and the inner bark is known as the cambium layer. We can say it because the beyond of sapwood due to the fact by the point it receives transformed into the sapwood. Hence is liable for the destiny increase of the trees.
(e) Inner bark: The internal pores and skin or layer overlaying the cambium layer are called internal bark.
(f) Outer Bark: The outer skin or cover of the tree is known as outer bark.
(g) Medullary rays: The thin radial fibers extending from pith to cambium layer are known as medullary rays. Its main function is to hold the annual rings of sapwood and heartwood in position and thereby imparts strength to it.