Leaf Identification
It’s not hard at all to learn the specifics of leaf identification. It will open up for you the whole world of plants, and you can learn not only what kind of plant you are looking at, but also some of the extraordinary functions of plants in providing not only food for themselves but in giving us life-sustaining oxygen as part of the process.
Before you can really learn the ins and outs of leaf identification, it helps to understand what a leaf is and what sort of work leaves accomplish. No matter what kind of leaf you want to identify--tree, bush, grass, flower, etc., it is this leaf that provides food for the plant to live and grow. The process the plant uses is called photosynthesis. The green substance that is in leaves is known as chlorophyll. Sunlight gives energy to chlorophyll, which in turn then takes water and carbon dioxide and produces sugar, otherwise known as carbohydrates, which feeds the plant. A byproduct of this process is oxygen. Plants take in carbon dioxide and give off oxygen which is necessary to sustain all life on earth, including our own.
When you look at a leaf, there are several indicators that point to what kind of plant it is. That means that when you have mastered leaf identification, you will be able to identify most trees or other plants simply by looking at what kind of leaves it has. Every leaf consists of three key parts. The first is the base. That’s the place where the stem and leaf meet. The stock of a plant is also known as the petiole. It’s thin and usually circular or cylindrical and it attaches the base of the plant to the lamina, or wide section of the leaf.
Leaf identification depends on what type of leaf margin or leaf blade a plant has. Leaves are either simple or compound. A leaf is simple if it is all one part--a single leaf blade with a bud where it attaches to the stem. The entire leaf is a single unit. A leaf is compound if it has a number of separate leaves coming from the same stock. There is more than one blade on a single stem. The bud forms where leaf stem attaches to the twig.
Compound leaves may have alternate or opposite arrangement. In an alternate arrangement, the leaves are not right across from one another--they are staggered. In an opposite arrangement, the leaves are directly across from one another on the stem. The next thing to look for is the shape of the leaves. Some may be entire, which means it is one single smooth surface all around the edge of the leaf. The edge of the leaf is technically known as the leaf margin. This margin can also be single-toothed, double-toothed or lobed all the way around. These are very helpful characteristics to know especially when your leaf identification involves those of fruit trees.
The final thing to do is to take all of this information you have gathered about the leaf --its shape, parts, etc.--and look it up in a leaf guide, where you will see photos of different leaves like yours and what kind of plant it is that has them. You can find leaf guides on the internet or you can buy them in bookstores. You can even find them at your local library. The small guides that fit in your pocket are the best kind because you can take them with you when you are outside exploring plants.