Leaf Shape Chart

A

Acicular Shape

Slender, stiff and sharp-pointed, often round or angled in cross-section rather than flat. Example: Pine. See it in leaf shapes

Acuminate Tip

The blade narrows gradually into a long, drawn-out point, sometimes called a drip tip. See it in margins, tips and bases

Acute Tip

The sides meet in a sharp point at less than a right angle, without a long taper. See it in margins, tips and bases

Alternate Arrangement

Leaves step up the stem one at a time, on alternating sides. Most trees. See it in leaf structure

Apex Anatomy

The tip of the blade. Compare it with the eight tips below: acuminate, acute, obtuse, rounded, truncate, emarginate, mucronate and cuspidate. See it in leaf anatomy

Arcuate Venation

Side veins curve forward and run toward the tip, roughly following the margin. Example: Dogwood. See it in leaf structure

Areole Modified leaf

The cushion-like spot on a cactus from which spines grow.

Aril Conifer

A fleshy cup that grows around a seed; red in yews.

Attenuate Base

The blade tapers gradually and runs a long way down toward the stalk. See it in margins, tips and bases

Auriculate Base

Two small, rounded, ear-like lobes at the base. See it in margins, tips and bases

Axil Anatomy

The upper angle between a leaf stalk and the stem, where the axillary bud forms.

Axillary bud Anatomy

Next season’s shoot, in the leaf axil. Every true leaf has a bud in its axil; the leaflets of a compound leaf do not. This is the surest way to tell a whole leaf from a leaflet. See it in leaf anatomy

B

Base Anatomy

Where blade meets stalk. Compare it with the eight bases below: cuneate, attenuate, rounded, truncate, cordate, auriculate, oblique and sagittate. See it in leaf anatomy

Bipinnate Compound leaf

The rachis carries side branches (pinnae), each with its own small leaflets. Example: Silk tree. See it in leaf structure

Blade Anatomy

The lamina, where photosynthesis happens. Its outline gives the leaf shape. Measure the blade’s length and width without the petiole. See it in leaf anatomy

Bract Modified leaf

A modified leaf associated with a flower or flower cluster, sometimes brightly coloured.

C

Ciliate Margin

A fringe of fine hairs along the edge; hold the leaf against the light. Example: Spiderwort. See it in margins, tips and bases

Clasping Attachment

The base partly wraps around the stem. Example: Wild lettuce. See it in leaf structure

Cordate Base

A heart-shaped notch where the stalk joins the blade. See it in margins, tips and bases

Cordate Shape

Broadly egg-shaped with a notch at the base where the stalk joins, like a playing-card heart. Example: Redbud. See it in leaf shapes

Coriaceous Surface

Thick, stiff and leathery, often with a glossy coat. Example: Holly. See it in leaf surfaces

Crenate Margin

Blunt, rounded teeth, like a scalloped hem. Example: Coleus. See it in margins, tips and bases

Cuneate Base

Straight sides narrow to the stalk at a sharp angle, like a wedge. See it in margins, tips and bases

Cuspidate Tip

The tip narrows abruptly into a sharp, stiff point (a cusp). See it in margins, tips and bases

D

Decurrent Attachment

The blade continues down the stem as narrow wings below the node. Example: Comfrey. See it in leaf structure

Deltoid Shape

Triangular like the Greek letter delta, broadest near the straight-ish base. Example: Cottonwood. See it in leaf shapes

Dentate Margin

Teeth that stick straight out, at right angles to the edge. Example: Viburnum. See it in margins, tips and bases

Dichotomous Venation

Veins fork again and again into equal pairs, with no midrib. Example: Ginkgo. See it in leaf structure

Dichotomous key Tree

An identification key that offers two choices at every step.

Doubly serrate Margin

Large teeth that carry smaller teeth along their edges. Example: Elm. See it in margins, tips and bases

E

Elliptic Shape

Broadest at the middle, with both ends narrowing about equally; roughly twice as long as wide. Example: Dogwood. See it in leaf shapes

Emarginate Tip

A small, shallow notch at the very tip. See it in margins, tips and bases

Entire Margin

No teeth or lobes: the edge runs in one smooth line. Example: Lilac. See it in margins, tips and bases

Even-pinnate Compound leaf

Paired leaflets along the rachis, with no terminal leaflet. Example: Tamarind. See it in leaf structure

F

Falcate Shape

Curved to one side like a sickle; the adult leaves of many eucalypts are falcate. Example: Eucalyptus. See it in leaf shapes

Fascicle Conifer

A bundle of pine needles held together at the base by a papery sheath.

Flabellate Shape

Fan-shaped: broad and rounded at the top, narrowing to a wedge at the base, often notched in the middle. Example: Ginkgo. See it in leaf shapes

G

Glabrous Surface

Smooth and hairless. It may be glossy or dull, but nothing catches your finger. Example: Lilac. See it in leaf surfaces

Glandular-dotted Surface

Hold it to the light: oil glands show as tiny translucent dots. Example: St John’s wort. See it in leaf surfaces

Glaucous Surface

A whitish or bluish waxy bloom; rub it and a darker green stripe appears, as in the lens view. Example: Cabbage. See it in leaf surfaces

H

Hastate Shape

Spear-shaped: a narrow blade with two basal lobes that flare out to the sides. Example: Sheep sorrel. See it in leaf shapes

I

Internode Anatomy

Stem between nodes. Very short internodes crowd leaves together, as in rosettes and on the spur shoots of larch and ginkgo. See it in leaf anatomy

L

Lamina Anatomy

Another name for the leaf blade.

Lanceolate Shape

About three to four times longer than wide, broadest in the lower part and tapering to the tip. Example: Willow. See it in leaf shapes

Lateral vein Anatomy

Carries water and sugars. Side veins branch from the midrib. How they run (pinnate, palmate, parallel, arcuate or forked) is the venation. See it in leaf anatomy

Leaflet Compound leaf

One blade-like part of a compound leaf. It never has a bud at its base.

Ligule Attachment

A small flap or ring of hairs where a grass leaf sheath meets the blade.

Linear Shape

Many times longer than wide, with margins running nearly parallel for most of the length. Example: Grass. See it in leaf shapes

Lobe Shape

A rounded or pointed projection of the blade, larger than a tooth.

Lyrate Shape

Lobed along the midrib, with a large, rounded end lobe and smaller lobes below. Example: Radish. See it in leaf shapes

M

Margin Anatomy

The edge: smooth, toothed or lobed. Look closely, with a hand lens if needed: tooth size, direction and spacing separate many otherwise similar trees. See it in leaf anatomy

Midrib Anatomy

The main central vein. A continuation of the petiole that stiffens the blade and carries the largest bundle of vessels. See it in leaf anatomy

Monocot Venation

Flowering plants with one seed leaf; most have parallel-veined leaves, like grasses and lilies.

Mucro Tip

A short, abrupt point at the end of a leaf, formed by the extended midrib.

Mucronate Tip

A rounded tip that ends in a short, abrupt point (a mucro), the extended midrib. See it in margins, tips and bases

N

Node Anatomy

Where a leaf joins the stem. Count the leaves at one node to read the arrangement: one is alternate, two opposite, three or more whorled. See it in leaf anatomy

O

Obcordate Shape

Heart-shaped with the notch at the tip and the narrow point at the stalk. Example: Wood sorrel. See it in leaf shapes

Oblanceolate Shape

Lance-like but broadest above the middle, tapering gradually toward the base. Example: Rhododendron. See it in leaf shapes

Oblique Base

The two halves meet the stalk at different points, as in elms and basswood. See it in margins, tips and bases

Oblong Shape

Sides more or less parallel for much of the length, with both ends rounded or blunt. Example: Banana. See it in leaf shapes

Obovate Shape

Egg-shaped but broadest above the middle, narrowing toward the base. Example: Magnolia. See it in leaf shapes

Obtuse Tip

The sides meet at a blunt angle wider than a right angle. See it in margins, tips and bases

Odd-pinnate Compound leaf

Paired leaflets along a central rachis, finished by a single terminal leaflet. Example: Ash. See it in leaf structure

Opposite Arrangement

Leaves in facing pairs at each node: maples, ashes, dogwoods, horse chestnut. See it in leaf structure

Orbicular Shape

Nearly circular, about as wide as long, with the stalk joining at the edge. Example: Aspen. See it in leaf shapes

Ovate Shape

Egg-shaped in outline, broadest below the middle and narrowing to the tip. Example: Basil. See it in leaf shapes

P

Palmate Venation

Several main veins spread from one point at the base of the blade. Example: Grape. See it in leaf structure

Palmately compound Compound leaf

Five or more leaflets spreading from the tip of the petiole like fingers. Example: Horse chestnut. See it in leaf structure

Palmately lobed Shape

Several lobes radiate from one point near the base, each with its own main vein. Example: Maple. See it in leaf shapes

Parallel Venation

Main veins run side by side from base to tip, typical of grasses, lilies and many other monocots. Example: Lily. See it in leaf structure

Peltate Shape

The stalk joins the underside of the blade, away from the edge, like the handle of an umbrella. Example: Nasturtium. See it in leaf shapes

Perfoliate Attachment

The base surrounds the stem completely, so the stem seems to pass through the blade. Example: Bellwort. See it in leaf structure

Petiolate Attachment

The blade is held on a petiole. Example: Maple. See it in leaf structure

Petiole Anatomy

The leaf stalk. It holds the blade out toward the light and carries water and sugars between blade and stem. A leaf with no petiole is called sessile. See it in leaf anatomy

Petiolule Compound leaf

The small stalk of a single leaflet.

Pinna Compound leaf

A primary division of a bipinnate leaf, carrying its own leaflets (plural pinnae).

Pinnate Venation

Side veins branch from one midrib like the barbs of a feather. Example: Beech. See it in leaf structure

Pinnately lobed Shape

Lobes arranged along both sides of a central midrib, separated by gaps called sinuses. Example: Oak. See it in leaf shapes

Pubescent Surface

Covered with short, soft hairs that make it feel velvety. Example: Tomato. See it in leaf surfaces

R

Rachis Compound leaf

The central stalk of a pinnately compound leaf, which carries the leaflets.

Reniform Shape

Kidney-shaped: wider than long, with a broad, rounded notch at the base. Example: Wild ginger. See it in leaf shapes

Rhomboid Shape

Diamond-shaped, broadest near the middle with fairly straight sides toward both ends. Example: Lamb’s quarters. See it in leaf shapes

Rosette Arrangement

Leaves crowded in a circle at ground level on a very short stem, as in dandelion and plantain. See it in leaf structure

Rounded Base

The base curves smoothly into the stalk. See it in margins, tips and bases

Rounded Tip

The tip forms one smooth, continuous curve. See it in margins, tips and bases

Runcinate Shape

Deeply cut along the midrib, with sharp lobes that point back toward the base. Example: Dandelion. See it in leaf shapes

S

Sagittate Base

Two pointed lobes aim back toward the stalk, like an arrowhead. See it in margins, tips and bases

Sagittate Shape

Arrowhead-shaped: two pointed basal lobes aim down, back toward the stalk. Example: Arrowhead. See it in leaf shapes

Samara Tree

A winged seed, as in maple and ash.

Scabrous Surface

Rough to the touch, like sandpaper, from short stiff hairs or tiny bumps. Example: Sunflower. See it in leaf surfaces

Scale leaf Conifer

A tiny, flattened leaf pressed against the twig, as in arborvitae and juniper.

Serrate Margin

Sharp teeth angled toward the tip, like a saw blade. Example: Rose. See it in margins, tips and bases

Serrulate Margin

Serrate, but with teeth so small you may need a hand lens. Example: Cherry. See it in margins, tips and bases

Sessile Attachment

The blade joins the stem directly. Example: Zinnia. See it in leaf structure

Sheathing Attachment

The lower part of the leaf forms a tube around the stem, with a ligule where the sheath meets the blade. Example: Grasses, corn. See it in leaf structure

Simple Compound leaf

A single blade on its petiole, with a bud in the axil. Example: Lilac. See it in leaf structure

Sinuate Margin

The edge weaves in and out in the plane of the leaf. Example: Chestnut oak. See it in margins, tips and bases

Sinus Shape

The gap between two lobes.

Spatulate Shape

Rounded at the end and narrowing gradually into a long, stalk-like base, like a spoon. Example: English daisy. See it in leaf shapes

Spinose Margin

Teeth tipped with stiff, sharp spines. Example: Holly. See it in margins, tips and bases

Spur shoot Conifer

A very short side shoot that carries clustered leaves, as in larch and ginkgo.

Stipule Anatomy

Small flap at the base of the petiole. Usually paired. Stipules may be leafy (pea), turn into spines (black locust) or drop early and leave only scars. See it in leaf anatomy

Stomatal bands Conifer

Whitish lines on the underside of many needles, formed by rows of breathing pores (stomata).

Succulent Surface

Thick and fleshy; a cut leaf shows pale, water-storing tissue inside. Example: Jade plant. See it in leaf surfaces

T

Tendril Modified leaf

A slender, coiling organ that lets a plant climb; in peas it is a modified leaflet.

Tomentose Surface

So densely woolly that the hairs hide the green surface beneath. Example: Lamb’s ear. See it in leaf surfaces

Trifoliate Compound leaf

Three leaflets on one petiole. Example: Strawberry. See it in leaf structure

Truncate Base

The base is squared off, almost straight across. See it in margins, tips and bases

Truncate Tip

The tip ends abruptly, as if cut straight across. See it in margins, tips and bases

U

Undulate Margin

The edge ripples up and down, out of the plane of the leaf. Example: Hosta. See it in margins, tips and bases

W

Whorled Arrangement

Three or more leaves ring each node, as in catalpa and bedstraw. See it in leaf structure