Leaf Shape

Leaves come in a variety of shapes. Having a firm grasp of the vocabulary associated with leaf shapes can help you to identify and talk about plants more effectively.

​This is a HUGE subject, so, grab yourself a beverage and get comfortable.

When describing leaf shape, some terms refer to the entire leaf, while others refer to specific parts of the leaf, such as the edge, tip, or base. Nearly all the terms are tied closely to the Latin word forms, so you are in luck if foreign language comes easily (or if you happen to already know Latin). Personally, I am not gifted in that particular area. Luckily for all of us, Latin is a pretty reliable language, when it comes to putting pieces of words together to make new words.

Leaf shape (Pearson Scott Foresman) Public Domain

Don’t let all these new words scare you off, and don't expect to be able to remember everything. You can always return to this page, or use a field guide, when describing leaf shapes or identifying unknown plants. The important thing is to become familiar with the different ways that leaves are described and categorized.

Leaf shape basics​

A leaf is simple, if it stands alone, or compound, if it is made up of tiny leaflets. Some compound leaves have a central shaft, called a rachis. [We will explore compound leaves in more detail another day.] If a leaf has a stem, that stem is called the petiole. There may or may not be growths on one or both sides of the petiole, called stipules.

Leaf and leaflet silhouettes

Leaves are first identified by their overall shape. They can be round, triangular, oval, rectangular, or diamond-shaped:

Stipules at base of rose leaf (Michael Becker) CC BY-SA 3.0

• Round leaves are orbicular. [Cabbage]
• Triangular leaves, with the stem attached to one side, are deltoid. [Some spinach]
• Oval leaves, with little or no point at the tip, are elliptic. If it is egg-shaped and wider at the base, it is ovate. [Apple]
• Rectangular, or strap-shaped leaves are lorate. If all of the corners of the rectangle are rounded, it is oblong. [Some lettuce]
• Diamond-shaped leaves are rhombic. If it looks more like a bricklayer’s trowel, it is truelate. [Beans]

---

Some leaves are shaped like a heart, kidney, fan, arrowhead, or spear:

• Heart-shaped leaves, with a stem or petiole in the notch at the top of the heart, are cordate. If the stem attaches at pointed end, it is obcordate. [Beets]
• Kidney-shaped leaves are reniform.
• Fan-shaped, semicircular leaves are flabellate. [Ginkgo]
• Arrowhead-shaped leaves are sagittate. [Some spinach]
• Spear-shaped leaves with a flared base are hastate. Those that are equally pointed at both ends are lanceolate. Leaves with slightly less pointed leaves are linear. If the terminal end is wider than the stem end, it is oblanceolate. [Peaches]

Some leaves are shaped like a teardrop, while others look more like the silhouette of a violin, a spoon, a sickle, or a hand:

• Teardrop shaped leaves, with the stem at the pointed end are obovate. If the stem is attached at the rounded end, it is ovate.
• Violin-shaped leaves are pandurate. Banjo- or lyre-shaped leaves, with the widest part at the terminal end, are lyrate. [Oak]
• Spoon-shaped leaves are spatulate. [Sedum]
• Sickle-shaped leaves are falcate. [Eucalyptus]
• Hand-shaped leaves are palmate. If the hand looks webbed, it is palmately lobed. If the hand shape has incisions that are less than halfway to the petiole, it is palmatifid. If those incisions go more than halfway, it is palmatipartite. If the incision nearly touch the petiole, it is palmatisect. If the lobes all reach the petiole, it is pedate. [Currants]

The Latin of lobes

Some leaves have protrusions, called lobes, that can be rounded (like your earlobes) or pointed. Lobes can be arranged pinnately (in pairs) or palmately (like a hand). Lobes can be gently waving lines, they can be sharp incisions, or they can fall somewhere in between. These features are usually described as relative to the midrib line. Depending on the type of lobe a leaf might have, descriptive suffixes are added:

• Lobes that go less than halfway through the leaf to the midrib get “-tifid” put on the end of their name. This comes from the Latin word (findere) for cleaving.
• Lobes that go more than halfway through the leaf to the midrib get “-partite” put on the end of their name. This comes from the Latin word (partiri) for share, or portion.
• Lobe cuts that nearly touch the petiole get “-tisect” added to the end of the name. This comes form the Latin word (secare) for cut. [Artichoke]

All about the base

The way leaves attach to the rest of the plant can also provide clues for identification.

• If the leaf tissue tapers down the petiole, it is attenuate.
• If it has rounded mouse-ear shapes at the point of attachment, it is auriculate.
• If the base of the petiole or stem is triangular and wedge-shaped, it is cuneate.
• If the two sides of attachment are different, it is oblique.

---

Here’s a tip

At the other end of the leaf, tip shape can also provide clues for identification. Leaf tips can be:

• Blunt (obtuse)
• Notched, slightly (emarginate), or more deeply (retuse)
• Pointed (acute)
• Rounded
• Squared off (truncate)

There is a lot of variation in leaf tips:

• Long, tapered, tips are subulate.
• Long, tapered, concave tips are acuminate. [Peace lily]
• Tapered tips that end in a cusp are cuspidate.
• Short, tapering points are apiculate. [Black hawthorn]
• Short, abrupt tips are mucronate. [Lentils]
• Stiff, bristly tips are aristate.
• Tail-like leaf tips are caudate.

---

Take it from the edge

The edge of a leaf is called its margin. Leaf margins provide an easy classification tool, since this trait stays consistent within a species. At the most basic level, leaf margins are:

• Smooth (entire) [Citrus]
• Lobed (lobate)
• Wavy (sinuate), undulating (undulate), scalloped (crenate)
• Fringed (ciliate)
• Spiny (spiculatus)
• Toothed (dentate), saw-toothed (serrate), doubly serrated, finely toothed (denticulate or serrulate) [Blackberry]

If the stem attaches to a leaf near the middle, rather than at an edge, it is peltate. [Nasturtium] If it looks as though the stem passes through the middle of the leaf, it is perfoliate. [Miner's lettuce]

You can find lots of online illustrations of leaf shapes, but, for right now, it has stopped raining and hailing and my garden is calling.