What is in a leaf?

What Is In a Leaf? 

This can be an observation and discussion or time for students to draw and label in a notebook, or information for a classroom or hallway bulletin board where each student adds a section to share. 

Hand each student (or small group) one kale leaf to examine closely and ask them to list the different parts of the kale leaf that they can see. After they share their observations, share the scientific names of the kale leaf parts and what the part does for the plant: 

BLADE: The main part of the leaf; all of it except the stem, veins and petiole. The blade of the leaf takes in sunlight and turns it into food. It is also where the plant “breathes.” 

LAMINA: Scientific word for blade of a leaf. 

STEM: The stem supports the leaf (like our skeleton supports us, and our legs), and, like the veins, transports (or moves) water, minerals and food energy. 

PETIOLE: The stalk of the leaf, which attaches to the stem of the plant. Its job is to hold the leaf to the rest of the plant. 

VEINS: Vascular bundle. The veins’ job is to transport (move) water, minerals and food energy through the leaf and on to the rest of the plant. The veins in a leaf do the same things that the veins in our bodies do! 

EPIDERMIS: The outer protective layer of a leaf. Sometimes the leaf may be waxy because the epidermis secretes a waxy protective cuticle. This waxy covering protects the leaf, and in the case of Kale, is a reason it is cold hardy.

If you have time to extend the discussion, you can ask students: “What’s in a leaf that we can’t see?” 

NUTRIENTS: Nutrients are the parts of food that give us energy. Explain that leaves can be considered the food factories for a plant. Things inside the leaf that we can’t see convert energy from the sun into energy, or nutrients, that plants can use, and that we can use when we eat plants! 

VITAMINS: The vitamins found in green leafy vegetables support our skin, help our immune system block sickness, help our body and our brain. Vitamins found in leafy greens: A, B, C, E, and K. 

MINERALS: The minerals found in leafy greens help our bones, heart and nervous system. They also keep us from getting sick. Minerals found in leafy greens: Calcium, Sulphur, Magnesium 

PHOTOSYNTHESIS: The process in leaves converting light energy to food for the plant. Carbon dioxide and water are used in photosynthesis and oxygen is released. We cannot see photosynthesis happening. It is important because without it, we wouldn’t get any energy from eating plants and the oxygen that is made.

CHLOROPHYLL: Leaves are the part of the plant richest in chlorophyll, which makes them green. So we actually CAN see chlorophyll. Chlorophyll is used in the process of photosynthesis. Chlorophyll supports our body in making blood, and our liver in getting rid of bad stuff in our blood (toxins) when we eat it.

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