Year 3: Plants

The Four Main Parts of a Plant

Curriculum Requirement

Identify and describe the functions of different parts of flowering plants: roots, stem/trunk, leaves and flowers.

Nature Examples

Roots

The part of the plant that usually grows underground.
Function: To anchor the plant firmly in the soil and to absorb water and nutrients.

💡 Fun Facts

  • The roots of a large tree can spread out two to three times wider than its branches.
  • Some plants, like carrots and parsnips, have a large 'taproot' that stores food for the plant over winter.
  • The tiny hairs on the end of roots dramatically increase the surface area for absorbing water.
🌳

Stem / Trunk

The main body or stalk of a plant that supports the leaves and flowers.
Function: To hold the plant upright and to act as a transport system, carrying water from the roots to the leaves.

💡 Fun Facts

  • The rings inside a tree trunk not only tell you its age but also what the weather was like each year—a wide ring means a good year for growing.
  • The strong, woody stem of a tree is called a trunk.
  • Some plant stems, like those on a stinging nettle, have tiny hollow hairs that act like needles to defend the plant.
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Leaves

The part of the plant where food is made.
Function: To capture sunlight and use its energy to make food for the plant through a process called photosynthesis.

💡 Fun Facts

  • Plants 'breathe' through tiny pores on the underside of their leaves called stomata.
  • The veins in a leaf are part of the plant's transport system, bringing water in and taking food out.
  • Some plants have leaves that are adapted for defence, like the sharp spines on a cactus.
🌼

Flowers

The reproductive part of a flowering plant.
Function: To produce seeds so that the plant can reproduce.

💡 Fun Facts

  • Flowers use bright colours and sweet smells as advertisements for passing insects, telling them where to find tasty nectar.
  • Pollination occurs when an insect, like a bee, carries pollen from one flower to another.
  • Not all flowers are bright and colourful; grasses have flowers too, but they are often small and green and rely on the wind for pollination.

Activities & Reflections

Activities

Celery Experiment

Stand a stalk of celery with leaves in a jar of water with food colouring. After a day, pupils will see the coloured water has been transported up the stem's 'pipes' (xylem) and into the leaves.

Function Match-up

Create cards with the plant parts (root, stem, leaf, flower) and separate cards with their functions (anchors the plant, carries water, makes food, makes seeds). Pupils can then work in pairs to match them up.

Plant Part Hunt

Take pupils outside to look at the plants in the school grounds. Ask them to find and sketch a plant, then label the four main parts they can see.

Reflections

Self-Reflection (Exit Ticket)

On a piece of paper, ask pupils to draw a simple flower and label its four main parts: roots, stem, leaves, and flower.

Paired Reflection (Think-Pair-Share)

Ask pupils to discuss with a partner: If a plant had no leaves, what problem would it have?

Group Reflection

In small groups, ask pupils to think about the vegetables we eat. Which part of the plant are we eating when we have carrots, celery, spinach, or broccoli?

Whole Class Share-Out

Ask the class: We learnt that flowers are often brightly coloured to attract insects. Why do you think the leaves and stems of most plants are green and not other colours?

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