The Description of Leaves

Apple Mint Leaves New York Aster Leaves White Bedstraw Leaves

There are a number of technical terms used for describing the arrangement and shape of leaves. These terms can be divided into several groups:

  1. Terms describing the arrangement of the leaves on the stem
  2. Terms describing the general structure of the leaf
  3. Terms describing the edge or margin of the leaf
  4. Terms describing the attachment of the leaf to the stem
  5. Terms describing the overall shape of a leaf or leaflet

The last group is the largest. There is also a large group of terms for describing the surface texture and appearance (e.g. degree of hairiness). These are not currently included here.

Terms describing overall arrangement of leaves on the stem

Alternate: show all
Leaves are attached to the stem singly, ascending either on alternate sides of the stalk, or in a spiraling pattern.

Opposite: show all
Leaves attached to stem in pairs that stand opposite each other.

Whorled: show all
Leaves attached to stem in groups of three or more at the same level, generally with symmetrical orientation.

Basal: show all
Leaves occuring in a tight cluster or rosette at the base of the plant.

Terms describing general structure of the leaf

Simple: show all
Leaves generally of simple, often convex shape, without partitions, lobes, or large lobe-like teeth. Leaves with small, marginal teeth or serrations are generally regarded as simple. The term entire refers leaves without any toothing or division

Lobed: show all
Leaves with distinct protrusions, either rounded or pointed. Pinnately lobed leaves have the lobes arranged on either side of a central axis like a feather. Palmately lobed leaves have the lobes spreading radially from a point, like fingers on a hand.

Dissected: show all
Leaves that are deeply or repeatedly cut into many partitions, but not into individual leaflets. Fern leaves are a classic example. The last example shown here would probably be considered compound as well as dissected, as some of the divisions go all the way to the center of the leaf.

Compound: show all
Leaves divided into individual leaflets. Leaflets are distinguished from leaves in that there is no bud at the base. Leaves may be palmately or pinnately compound. Some are doubly or even triply pinnate.

Terms describing the margin of the leaf

Entire: show all
Margins without teeth or serrations. The term entire refers to leaves that are neither toothed, lobed, or compound, i.e. simple with smooth margins.

Sinuous or sinuate: show all
Margins with more or less wavy or sinuous structure in the plane of the leaf.
Undulate: show all
Margins wavy or undulating out of the plane of the leaf.

Toothed: show all
Margins more or less toothed. The term is generic and encompasses the terms serrate, dentate, and crenate, which describe different types of relatively fine, continuous toothing, as well as situations where the teeth are widely spaced, large and lobe-like, or occur at different scales (doubly toothed).

Serrate: show all
Margins with continuous, sharp, forward-pointing teeth, like the blade of a ripsaw.

Dentate: show all
Margins with continuous, generally outward-pointing teeth.

Crenate: show all
Margins with continuous, rounded, and generally outward-pointing teeth; dentate with conspicuously rounded teeth.

Terms describing the attachment of the leaf

Petioled or petiolate: show all
Leaves with a definite footstalk or stem (petiole), long or short.

Sessile: show all
Leaves without any footstalk or stem.

Clasping: show all
Leaves with basal lobes that wrap around or clasp the main stem. Generally such leaves also qualify as sessile.

Perfoliate: show all
Leaves united at the base so that they appear to be pierced by the main stem.

Terms describing the shape of the leaf of leaflet

Ovate: show all
Leaves generally egg-shaped, with the broader portion towards the base. Often pointed at the tip. Sometimes includes elliptical leaves that are not clearly broader towards the base. May be modified as in narrowly ovate or broadly ovate.

Obovate: show all
Leaves generally egg-shaped, but with the broader portion clearly towards the tip.

Elliptical or elliptic: show all
Leaves shaped like an ellipse; that is, generally symmetrical, elongated, and more or less evenly rounded at both ends.

Lanceolate: show all
Leaves shaped like a lance-head, much longer than wide, and, in technical usage, broader towards the base. The reverse situation would be technically termed oblanceolate.

Linear: show all
Leaves long and thin, many times longer than wide, with parallel margins. Grass is an example.

Cordate: show all
Leaves heart-shaped with the lobes at the base of the leaf.

Obcordate: show all
Leaves heart-shaped with the tip at the base of the leaf.