Tree experts such as Chris Roddick of the Brooklyn Botanic Garden need only examine the leaves of a tree to distinguish between a maple and a white oak. Today, he joins Martha to demonstrate some basic tree-identification techniques. The first thing to consider is the arrangement of the leaves: Do they alternate on either side of the branch, or are they directly opposite each other? If the leaves are arranged in an alternating pattern, the tree could be an oak, hickory, or elm. A tree with leaves that are opposite one another might be a maple, ash, or dogwood.
Next, look at whether the leaf is simple or compound. A compound leaf, such as the hickory leaf, is divided into two or more leaflets; an example of a simple or undivided leaf is the dogwood. The shape of the leaf and its edges, known as its margins, are also clues to a tree's identity. Elm leaves are almost always lopsided or uneven at the base. The beech, one of Martha's favorites, has smooth, or entire, margins. The leaves of the pin oak are lobed, and the margins have pointed tips.
In addition, the fruit of the tree also reveals a lot. What you may have called helicopters as a child are actually called samaras, a type of fruit from a number of different trees. The samara of the elm is circular, the samara of the ash is long and spiky, and the double samara, the kind that kids peel apart and stick to their noses, is from the maple. During the winter, when there are no leaves or fruit on deciduous trees, the branches, buds, and bark all serve as identifying characteristics.
Learn more about Brooklyn Botanic Garden. Arthur Harmount Graves's "Illustrated Guide to Trees: A Handbook of Woody Plants of the Northeast and Adjacent Canada," George W.D. Symonds's "Tree Identification Book," and Elbert L. Little's "National Audubon Society Field Guide to North American Trees: Eastern Region" and "National Audubon Society Field Guide to North American Trees: Western Region" are available from Amazon.