Science Fenns K-5Grades K to 5
A prickly pear cactus and a mesquite tree on dry Texas ground, one with waxy pads and one with a long taproot sketched below.

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Plant Structures

Waxy leaves and deep roots.

Lesson 38 of 40

Try this first

Before we start

Today’s story

Plant Structures

Texas heat can be harsh. Plants there have special parts that help them survive.

A waxy leaf holds in water, like a raincoat. A deep root reaches water far below the surface. Mesquite roots can go very deep. Thorns keep animals from eating the plant.

These structures are not chosen by the plant. They are part of how that kind of plant grows. Follow the steps.

See it

Five steps. Every time.

    Hands on

    Wax Test

    20 minutes · Do this with a grown-up nearby

    You need

    • Waxy leaf such as a magnolia or holly
    • A thin, soft leaf such as lettuce
    • Dropper
    • Water
    • Paper towel
    • Hand lens

    Do this

    1. Lay each leaf flat.
    2. Place one drop of water on each.
    3. Watch the drop.
    4. Tilt the leaf and see if it rolls.
    5. Dry and repeat.
    6. Draw each drop.
    7. Say which leaf saves water.
    Write or draw: Two drawings showing the water drop and a sentence about it.

    Watch for: Water beads up on waxy leaves and runs off. On other leaves it soaks in or spreads.

    Safety: Do not eat any leaf.

    Same every time

    Three rules

    Rule 1Structures help survival.

    They fit the place.

    Rule 2Different places, different plants.

    No one plant fits everywhere.

    Rule 3Look closely.

    Leaves, roots and stems all have clues.

    Grandpa Fenn’s notebook

    Say it like a scientist

    structure
    A part of a living thing.
    taproot
    A long main root that grows deep.
    waxy
    Coated with a thin layer of wax.
    survive
    To stay alive.

    Poppy’s quiz

    Six questions

    Tap an answer. Green means right. You will see why.

    Talk about it

    Say it out loud

    • How do you know a plant is built for dry land?
    • What plants near your home look built for heat or cold?
    Did you know

    Mesquite roots have been found reaching down dozens of feet to find water.

    Someone who does this

    A botanist studies how plants live in different places.

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