Trees are like people, they have characteristics that set them apart from one another. Before you can do much work on a forestry activity, you should learn how to identify common trees. A good way to learn how to identify trees is to make a leaf collection.
Types of leaves
There are two main types of trees broadleaf and coniferous. Coniferous trees have leaves that are needle like or scale like. When identifying broadleaf trees, you first must learn about arrangement of the leaves. The terms used to describe leaf arrangement are alternate and opposite. These terms describe the location of the leaves on a twig. Alternate leaves means that leaves are located on alternate sides of the twig. Opposite leaves means that two leaves are directly across from each other on the twig. Most trees in Louisiana have alternate leaves.
The next step is to determine if leaves are simple or compound. Simple leaves have single blades. Compound leaves have more than one blade on the stem. These are called leaflets. A leaf can be distinguished from a compound leaflet by the bud on the twig at the base of the leaf. There is no bud at the base of a leaflet.
The third step is to determine whether the leaf edge is smooth, toothed, or lobed.
How to make a leaf collection
Collect typical sized and shaped leaf specimens without holes or spots. You should collect leaves on dry days to help prevent mold from growing. You will then need to dry your leaves. You can use a plant press, but if you don’t have access to one, take your leaf specimens and place them between the pages of a catalog, magazine or newspaper. Make sure you identify the leaf when putting to dry. You should let your leaves dry for several weeks. You can put a little pressure on top of the magazines to keep the leaves flat like stacking some books on top of it. When you collect compound leaves, collect the entire leaf when possible.
Rules for creating a leaf collection
a. Any 4-H member may participate.
b. Submit a fresh mounted collection of leaves of Louisiana trees according to the following specifications:
1. Each specimen shall be dried and individually mounted on conventional size material about 8 1/2" x 11" and displayed in a conventional loose-leaf notebook binder or similar ringed folder. The specimens may be mounted on pressure sensitive self-adhering transparent plastic sheets or other similar material. Gluing the specimen directly to heavy duty paper is also acceptable.
2. A label about 2 1/2" x 3" in size shall be glued to the lower right hand corner of each display sheet. The label shall contain the scientific and common name, general description of the tree (i.e., size, habitat, etc.,) location at which leaf was collected, date collected and collector's name.
3. The front page of the notebook shall have typed or printed on it "Tree Leaves of Louisiana." The exhibitor's name, age, 4-H club, parish and address shall also be typed or printed on this page.
c. Exhibit must be submitted in March or April prior to Achievement Day.
d. Must have at least 25 specimens to qualify, but you can have more.
e. Scoring: 3 points per correctly identified specimen; 1point for each incorrect identification; 25 points for organization and appearance
NOTE: New material must be collected for each year. Using old collections or even parts of old collections from previous years is not allowed.