Native & Naturalized Plants of the Carolinas and Georgia

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Leaves,

adapted from Woody Plants of the Blue Ridge by Ron Lance. Used by permission.

To see photographic examples of a term, click the camera next to it in the list of botanical terms.

 

Basic morphology:

A simple leaf consists of a blade, joined to the woody twig by a stalk, the petiole.
The area of twig where the petiole arises is called the node; usually a bud is also found there.

Sometimes the petiole is very short or lacking; then the leaf is sessile.
In some monocots, a basal sheath replaces the petiole, and partially envelopes the stem.

Stipules are leaf-like modifications of leaf bases, on petioles or twigs of some plants.

blade petiole bud stipule twig node sheath


Venation:

The midrib is the largest, central vein, becoming the petiole below the blade.
Main veins branch from the midrib into a successively smaller network.

Parallel (in many monocots) shows many straight veins side by side from base to tip.


Texture:

Leaf surfaces can be smooth and hairless (glabrous), or “hairy” in some way. (See discussion on general features.) Additionally, leaf surfaces can be

Coriaceous leaves are thick, stiff, or leathery.

If they persist beyond Autumn and Winter seasons and fall after new leaves emerge in Spring they are evergreen. Deciduous leaves fall before or during the Autumn season. Some leaves may be tardily deciduous (semi-evergreen); these fall gradually during Winter, or only after sufficiently cold weather.


Leaf types:

Simple leaves have one blade.
Compound leaves have divided blades, each blade-like portion called a leaflet.

Types of compound leaves are:

simple leaf pinnate leaf bipinnate leaf rachis petiole palmate trifoliate

Leaf shape:

lobed subulate acicular linear lanceolate falcate spatulate obovate ovate elliptical deltoid flabellate cordate reniform

Leaf tips:

acuminate acute obtuse rounded truncate emarginate mucronate cuspidate

Leaf bases:

cuneate acute rounded truncate cordate auriculate connate

Leaf margins:

entire undulate revolute ciliate remotely toothed serrulate crenate dentate