Video:What Are Teeth on a Leaf?with Nick Richards
Teeth on a leaf's edge are an easy way to identify what type of leaf it is. Here's a video explaining the function and meaning of teeth on a leaf.See Transcript
Transcript:What Are Teeth on a Leaf?
Hi, I'm Nick and today for About.com, I'm going to explain what teeth are on a leaf, with information provided by Steve Nix, the Forestry Guide at About.com.
Identifying Teeth on Leaves
Tree leaves come in many different shapes, sizes and colours, which can make it difficult to identify which leaf belongs to which tree. One of the easiest methods to use to identify a leaf is to examine the outside edge, otherwise known as the leaf margin. There are a number of different types of leaf margin, including entire, toothed, lobed and parted. Toothed leaves have serrated edges that can vary in size, shape and even sharpness. Other names for toothed leaves include serrated, crenate and sawtoothed. Leaves with entire margins have a smooth edge to contrast the sharper margins of toothed leaves.
Types of Leaves That Have Teeth
There are several trees from all over the world that have toothed leaves. These include species such as elms, birches, alders, hickories, poplars, mulberries and chestnuts. There are several reasons why it is beneficial for certain leaves to have developed toothed margins. For one, on large, single leaves, the serrations on the margin encourage water to form droplets and fall, instead of pooling on the leaf. Other times, sharp leaf margins can be used to deter potential predators, with holly proving a particularly good example of leaves with extremely sharp teeth!
Now you know why leaves have teeth! For more information on leaf identification, visit education.About.com.