Parts of a Tree
Trunks- trunks and branched give a tree its shape. The xylem is the woody, center
part of the trunk. It has tiny pipelines that carry water with a
small amount of dissolved minerals from the roots to the leaves.
This water is called sap.
The combine, which surrounds xylem. Its job is to make the the
trunk, and roots grow thicker. The food made by the leaves moves
though the phloem to the other parts of a tree. The cork layer is
the outer back of a tree. It forms a skin of hard, dead tissue
that protects the living inner parts from injury. The outer bark
stretches to let the trunk and branches grow thicker. As the
trunk and branches grow thicker, they push against the bark from
time to time and replace it with a new layer.
Leaves- The main job of the leaves is to make food for the
tree. Every leaf has one or more veins
. The tissue that surrounds the veins contains tiny green bodies
called choloplasts. Water
from the roots passes though the xylem of the trunk, branches,
and leaves to the chloroplasts.
Roots-are long, underground branches of the trunk. The roots
anchor a tree in the ground and absorb water with dissolved
minerals from the soil. The main roots branch out into small
roots, which in turn , branches out into still smaller roots. The
main roots of most trees begin to branch out 1 or 2 feet under
the ground. Some trees have one main root larger than the others.
This root, called a taproot,
extends straight down 15 feet or more.
Seeds- Are the means by which all trees except tree farms
reproduce. Most trees begin life as a seed. The young tree that
develops from this seed is called a seedling. After a tree
reaches height of feet or more and its trunk becomes 1 to 2
inches thick, it is called a sapling. Many trees reach a height
of more than 100 feet. Some old trees have trunks more than 10
feet in diameter.