Different Tree Parts And Functions: Parts Of A Tree Lesson For Kids

Uprooted Large Green Leaved Tree
(Image credit: andreusK)

Trees are sometimes depicted in simple form in kids’ books, like a lollipop with a rounded crown and a slender trunk. But these incredible plants are much more complex than one might think and perform water-moving tricks that are beyond the capabilities of humans.

When you are putting together a “parts of a tree” lesson for children, it’s a great opportunity to engage them with the magical world of nature. Read on for some ideas on interesting ways to show how a tree functions and the work the different tree parts accomplish.

How a Tree Functions

Trees are as diverse as humans, different in height, breadth, shape, color and habitat. But all trees function in largely the same way, with a root system, a trunk or trunks, and foliage. What do parts of a tree do? Each of these different tree parts has its own function.

Trees create their own energy using a process called photosynthesis. This is accomplished in the tree’s leaves. The tree mixes air, water and sunshine to make energy which it needs to grow.

Different Tree Parts


Generally, a tree relies on its root system to hold it upright in the soil. But roots also play another important role. They take up the water and nutrients it needs to survive. 

The smallest roots are called feeder roots, and they take in water from beneath the soil by osmosis. The water and nutrients in it are transferred to larger roots, then move slowly up the tree trunk to the branches and leaves in a sort of botanical plumbing system.


The tree trunk is another important part of the tree, although only the outer part of the trunk is alive. The trunk supports the canopy and raises the tree branches off the ground to where they can get better light. The outer bark is armor for the trunk, covering it and protecting it, while the inner bark is where the transport system is located, carrying water up from the roots. 


A third main part of the tree is called the crown. It is the part with the branches and leaves that can offer the tree shade from the hot sun in summer. The main job of the branches is to hold the leaves, while the leaves themselves have vital roles. 


First, they are the food factories of the tree, using the sun’s energy to convert the carbon dioxide in the air into sugar and oxygen. The green material in leaves is called chlorophyll and is essential in photosynthesis. The sugar provides food for the tree, allowing it to grow. 

Leaves release water and oxygen into the atmosphere. As they release water, it creates a difference in water pressure in the tree’s transport system, with less pressure on top and more in the roots. This pressure is what pulls water from the roots up the tree.

Teo Spengler

Teo Spengler has been gardening for 30 years. She is a docent at the San Francisco Botanical Garden. Her passion is trees, 250 of which she has planted on her land in France.