Parts of a Stem, Its Structure and Functions

This botany lesson is designed for 6 to 12-year-old children. It demonstrates the basic structure of a stem, its parts, and its functions.

This video lesson provides a practical life experience of learning about the stems of different plants by taking a nature walk along with the child. It also introduces the child to the various parts of the stem, such as the nodes, petiole, axillary bud, etc.

What is a Stem of the Plant?

The term ’stem’ refers to the plant structure supporting the plant and connecting the roots to the leaves and flowers. It is also called the central axis of the plant because it is found above the ground. The stem is one of the most important parts of a plant. It supports the leaves, flowers, and fruits, and is responsible for transporting water, nutrients, and sugars throughout the plant.

Stems are of two types:

unbranched like the palm tree
branched like rose plants.

Note: stems of some plants grow underground, such as the potato. It can be herbaceous (soft) or woody in nature (trunk).

Functions of a Stem

Understanding the functions of the stem is essential for anyone interested in plant biology and horticulture. The stem of a plant has several important functions, including:

The primary function of the stem is to provide mechanical support to the plant.
It helps to transport absorbed water and minerals from roots to different parts of the plant.
It provides a location for leaves to grow and carry out photosynthesis.
It stores food and water for later use.
It helps transport the food prepared by leaves using photosynthesis (i.e., sugars) to the rest of the plant.
It helps in producing new growth to extend the length of the plant.
It helps in hosting buds that can grow into new branches or flowers.

What Are the Five Different Parts of a Stem?

A stem consists of five distinct parts:

Nodes,
Internodes,
Terminal or apical bud,
Lateral or axillary bud,
Petiole

Nodes

The stem is made up of a series of nodes and internodes. Nodes are the point of attachment where the buds, leaves, aerial roots, and branches originate. A stem can support several leaves and buds.

Functions of Nodes

It helps the plant to form buds, leaves, and branches.
It provides structural support to the plant.

Internodes

Internode is the region between two nodes. It is also known as the ‘internodal’ zone.

Functions of Internodes

It acts like branches or blood vessels that carry and distributes food, water, and minerals to each part of the plant
It is responsible for the growth in the length of the plant.

Terminal or Apical Bud

Buds are small, undeveloped shoots that can grow into new branches or flowers. They are found in the axils of the leaves and at the tip of the stem. Buds are essential for the growth and development of the plant. The apical bud is the small extension found at the tip of the plant (Apex of the plant).

Functions of Apical Bud

It acts as the primary growing point in the stem.
It produces growth hormones called auxin, which stimulates cell growth and division. It further helps the plant to grow vertically upwards.

Lateral Bud or Axillary Bud

The tiny bud develops from the axil (the region between the stem and a leaf). It gives rise to new branches of stem or flower.

Functions of Axillary Bud

It helps a plant to develop its lateral branches and leaves.
It helps a plant to grow flowers (the reproductive part of a plant)

Petiole

Leaf petioles are thin stalks that connect the stem to the base of a leaf.

Functions of Petiole

It provides strength and support to the leaf
It helps in transporting water and minerals to the leaf and food from the leaf to the rest of the plant

Some Other Facts About Stem

The majority of stems grow above ground, but some of them grow underground such as potatoes.

A stem can be unbranched or highly branched; it may also be herbaceous or woody.
Stems may range in length from a few millimeters to hundreds of meters.
Stems also vary in diameter, depending on the plant type.

Invite the child for a nature walk. Allow them to pick their favorite plant and ask them to identify the different parts of its stem.

Watch the video to learn about the parts of the stem and how they differ in appearance and help the plant to grow.

FAQs

What is the function of the stem?

The stem is the part of the plant that supports the branches, leaves, flowers, and fruit. It also transports water and nutrients from the roots to the rest of the plant.

What are the 6 parts of the stem?

The six parts of the stem are the nodes, internodes, buds, leaves, vascular bundles, and the terminal bud. The nodes are the points on the stem where leaves are attached, while the internodes are the spaces between the nodes. Buds are small, undeveloped shoots that can grow into new branches or flowers. Leaves are the structures that grow from the nodes and are responsible for photosynthesis. Vascular bundles are the structures that transport water and nutrients throughout the plant. The terminal bud is located at the tip of the stem and is responsible for the plant’s growth in length.

What is the difference between a node and an internode?

Nodes are the points on the stem where leaves, branches, and buds are attached. Internodes are the sections of the stem between the nodes.