Southern forests are among the most diverse in the United States, containing a mix of tropical and temperate plants. Regions characterized by a majority of tropical plants contain a lush mixture of large leaves that can be seen year-round, while more temperate regions are renowned for gorgeous fall color and stately conifers. Leaf identification is a great way to get to know Southern forests and landscapes more intimately.
Leaf shape is an excellent starting point for leaf identification. Leaves that are attached to the branch singly, like those of most oaks and maples, are referred to as simple leaves. Leaves attached to the stem in clusters are known as compound. Simple leaves come in many interesting shapes, such as the distinctive, mitten-shaped leaves of the sassafras tree. Compound leaves may be in a linear arrangement, such as the honey locust, or in a fan-shaped arrangement, such as the saw-palmetto.
The edge of the leaf, or leaf margin, is a helpful identification feature. Margins that are completely smooth are called entire, like those of the willow oak. Serrate margins, as with the American beech, look like a row of small teeth. The deep, rounded indentations of burr oak leaves are an example of lobed leaves, as are maples, with their pointier, more symmetrical indentations.
Many trees with stunning fall color are found in the South. Sweetgums are distinct for their assortment of yellow, orange and red leaves that appear simultaneously on the same tree. The sugar maple stands out in any landscape with its blazing orange and red leaves, while eastern cottonwoods glow a golden yellow in the background. Oaks do not offer much of a fall show, most turning a dull brown before dropping.
Deciduous or Evergreen
Deciduous leaves drop from the tree or shrub in late fall, while evergreen leaves stay on the plant throughout the year. Broadleaf evergreens, like the southern magnolia, are easy to identify in winter when their large, shiny leaves stand out among the bare branches of deciduous trees. The unusual needles of the bald cypress change color and drop each autumn, putting them in the unique category of deciduous conifers.
The South has a number of coniferous trees, which typically have needles for leaves. Needles are most commonly identified by their size and stem attachment. Shortleaf pine needles are long and thin with a slight twist, attached to the stem in clusters of two to three. Eastern hemlock needles are short and flattened, silvery underneath and attached to the stem singly.