So You Want to Do a Project about Leaves!
To collect leaf rubbings.
- 2 or 3 leaves from different plants
- 3 or 4 sheets of newspaper
- 2 sheets of white copy paper
CAUTION: Do not pick leaves from plants such as poison ivy or poison oak. Ask for adult assistance if you are not sure that a leaf is safe to handle.
- With adult permission, collect the leaves from different trees and/or bushes.
- Place the sheets of newspaper on a table to protect the table's surface.
- Arrange the leaves on one sheet of copy paper so that their rough sides are up and the leaves do not overlap.
- Cover the leaves with the second sheet of copy paper.
- With firm pressure, rub the crayon across the paper over the leaves.
A colored rubbing of each leaf is made.
More of the crayon is rubbed off by the rough edges and ridges, so these features of the leaves show up as darker areas on the paper. The petiole (stalk) of a leaf contains long, tubelike structures that are called veins when they branch out in different directions when they reach the blade (large part of a leaf). If the leaf of a plant consists of a single blade, it is called a simple leaf, although the edges may be indented in many ways. If the leaf blade is divided into two or more separate parts, the leaf is a compound leaf. Each leaflike part of a compound leaf is called a leaflet.
The pattern of large veins in the blade is called the venation of the leaf. There are two basic types of venation: parallel and netted. In leaves with parallel venation, such as those of a lily or grass, the large veins are parallel to each other and the edge of the leaf. In leaves with netted venation, such as those of a sunflower or oak, the veins branch and rebranch in the blade.
Netted venation can be grouped into two types: palmate and pinnate. If the large veins in netted venation all start at the end of the petiole and extend through the blade like fingers from the palm of a hand, the netted venation is called palmate venation. The leaves of the sycamore and sugar maple trees have palmate venation. If a single large vein runs through the center of the leaf and smaller veins branch from it in a feather shape, this type of netted venation is called pinnate venation. The leaves of oak, elm, and apple trees have pinnate venation.
Compound leaves, like veins, can have a palmate or pinnate pattern. If the leaflets fan out from a common point at the petiole, such as those of a clover, horse chestnut, or poison ivy, they are called palmately compound. If the leaflets are attached along a central stalk, such as those of a rose, ash, walnut, or hickory, they are called pinnately compound.
For Further Investigation
Did the leaves you found all have the same basic pattern, or were they different? How many different kinds of leaf patterns can you find? A project question might be, How many different leaf patterns can be found in my neighborhood?
Clues for Your Investigation
Collect more leaves from your neighborhood and make rubbings of them. Compare the vein patterns on the leaves. Group them by vein pattern type. You may want to use a plant field guide to identify the plant that each leaf comes from. Display the leaf rubbings arranged and labeled by type.
References and Project Books
Althea. Trees and Leaves. New York: Troll, 1990.
Burnie, David. How Nature Works. Pleasantville, N.Y.: Reader's Digest, 1991.
Burton, Jane, and Kim Taylor. The Nature and Science 0f Leaves. Milwaukee: Gareth Stevens, 1997.
Forey, Pam. Wild Flowers 0/ North America. San Diego: Thunder Bay Press, 1994.
Hershey, David R. Plant Biology Science Projects. New York: Wiley, 1995.
Kowalski, Kathiann M. The Everything Kids' Nature Book. Holbrook, Mass.: Adams Media Corporation, 2000.
Suzuki, David. Looking at Plants. New York: Wiley, 1991. VanCleave, Janice.janice VanCleave's Biology/or Every Kid. New York: Wiley, 1990.
____.janice VanCleave's Plants. New York: Wiley, 1996.
____.janice VanCleave's Science around the Year. New York: Wiley, 2000.
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.