Probably the best way to identify a houseplant is through matching it to a picture in a book or on the web. There are plenty of websites and books that can help you do this. However, there might be cases where you are not able to match your plant to a picture. If this happens, you may need to contact an expert, or botanist, to help you with identification. If you do need to contact an expert, chances are good that he or she will need to know some specifics about the leaves of the plant. This article will help you learn and identify different type of leaves and leaf structure.
Leaf arrangement
The way that the leaves are arranged on the stem is a big clue to the type of plant that you are looking at. There are four main types of leaf arrangement:
Opposite—opposite or opposing leaves are common in plants belonging to the mint family. These types of leaves grow in pairs, and both leaves sprout out together in opposite directions from one node on the stem.
Alternate—alternating leaves have only one leaf attached at each node. The leaves alternate with one shooting off to the left and the next off to the right. Most ivies and climbing plants feature this arrangement.
Whorled—the whorled arrangement features three or more leaves attaching to each node. Some plants with this leaf type have names that reflect this feature. For example, the whorled peporomis features whorled leaves.
Basal Rosette—the fourth type of leaf arrangement is reserved for leaves that do not grow from a stock. There are plenty of houseplants that feature these types of leaves. One of the most common houseplants is the spider plant, which has the basal rosette leaf arrangement.
Leaf form
Another way of identifying houseplants from their leaves is to identify the leaf form. Botanists use leaf form to separate types of plants into two broad categories: simple and complex.
Simple leaves—simple leaves have the basic structure of a broad blade (leaf) on a leaf stock or petiole. Some simple leaves are sessile meaning that they do not have a stem; rather, sessile leaves are seated directly on the branch. Plants such as the popular philodendron plants, croton, and corn plant have simple leaves.
Compound leaves—compound leaves are divided into smaller leaflets. There are several different ways for the leaves to be compounded; for example, the leaflets might all come from the main stem. When the leaves all come from the main stem they are said to be pinnately compound. When the leaflets all originate from one common point (not along a stem) they are said to be palmately compound. Ferns are a classic example of pinnately compound leafs and the dwarf schefflera is an example of a plant with palmately compound leafs.
Leaf shape
Another distinction between plants is the shape of the leaves. There are about as many adjectives to describe leaf shapes as there are leaf shapes. Some of the more common descriptions include the following.
Heart shaped—heart shape leaves are easy to distinguish because the leaves are shaped like hearts. The heartleaf philodendron is a classic example of a plant with heart shaped leaves.
Palm shaped—the other shape of leaf that is easy to identify is the palm shaped leaf. These leaves are shaped rather like the palm of a hand with thick “fingers” coming from the center. Most palm plants feature palm shaped leaves, as does the popular canary creeper.