Glossary of leaf morphology

The following is a defined list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular or irregular, may be smooth or bearing hair, bristles or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article.

Chart illustrating leaf morphology terms

Leaf structure

A ternate compound leaf with a petiole but no rachis (or rachillae)

Leaves of most plants include a flat structure called the blade or lamina, but not all leaves are flat, some are cylindrical. Leaves may be simple, with a single leaf blade, or compound, with several leaflets. In flowering plants, as well as the blade of the leaf, there may be a petiole and stipules; compound leaves may have a rachis supporting the leaflets. Leaf structure is described by several terms that include:

Image	Term	Latin	Description
	bifoliolate		Having two leaflets[1]
	geminate
	jugate
	bigeminate		Having two leaflets, each leaflet being bifoliolate
	bipinnate	bipinnata	The leaflets are themselves pinnately-compound; twice pinnate
	biternate		With three components, each with three leaflets
	imparipinnate		With an odd number of leaflets, pinnate with a terminal leaflet (the opposite of paripinnate)
	odd-pinnate
	paripinnate		Pinnate with an even number of leaflets, lacking a terminal leaflet (the opposite of imparipinnate)
	even-pinnate
	palmately compound		Consisting of leaflets all radiating from one point
	pinnately compound		Having two rows of leaflets on opposite sides of a central axis, see imparipinnate and imparipinnate
	simple		Leaf blade in one continuous section, without leaflets (not compound)
	ternate	ternata	With three leaflets
	trifoliate	trifoliata
	trifoliolate	trifoliolata
	tripinnate	tripinnata	Pinnately compound in which each leaflet is itself bipinnate

List of leaf (or leaflet) shapes

Being one of the more visible features, leaf shape is commonly used for plant identification. (Similar terms are used for other plant parts, such as tepals)

Oddly pinnate, pinnatifid leaves (Apium graveolens, celery)

Partial chlorosis revealing palmate venation in simple leaves of Hibiscus mutabilis

Image	Term	Latin	Refers principally to	Description
	acicular	acicularis	entire leaf	Slender and pointed, needle-like.
	acuminate	acuminata	leaf tip	Tapering to a long point in a concave manner.
	acute		leaf tip or base	Pointed, having a short sharp apex angled less than 90°.
	apiculate	apiculatus	leaf tip	Tapering and ending in a short, slender point.
	aristate	aristata	leaf tip	Ending in a stiff, bristle-like point.
	attenuate		leaf base	Having leaf tissue taper down the petiole to a narrow base, always having some leaf material on each side of the petiole.
	auriculate		leaf base	Having ear-shaped appendages near the petiole.
	asymmetrical		entire leaf	With the blade shape different on each side of the midrib.
	caudate		leaf tip	Tailed at the apex.
	cordate	cordata	entire leaf	Heart-shaped, with the petiole or stem attached to the notch.
	cuneate	cuneata	leaf base	Triangular, wedge-shaped, stem attaches to point.
	cuspidate		leaf tip	With a sharp, elongated, rigid tip; tipped with a cusp.
	deltoidor deltate	deltoidea	entire leaf	Shaped like Greek letter Delta, triangular, stem attaches to side.
	digitate	digitata	entire leaf	With finger-like lobes, similar to palmate.[2]
	elliptic	elliptica	entire leaf	Oval, with a short or no point.
	ensiform	ensiformis	entire leaf	Shaped like a sword, long and narrow with a sharp pointed tip.
	emarginate		leaf tip	Slightly indented at the tip.
	falcate	falcata	entire leaf	Sickle-shaped.
	fenestrate	fenestrata		Large openings through the leaf, see perforate. Sometimes use to describes leaf epidermal windows.
	filiform	filiformis	entire leaf	Thread- or filament-shaped.
	flabellate	flabellata	entire leaf	Semi-circular, or fan-like.
	hastate	hastata	entire leaf	Spear-shaped: Pointed, with barbs, shaped like a spear point, with flaring pointed lobes at the base.
	laciniate		entire leaf	Very deeply lobed, the lobes being very drawn out, often making the leaf look somewhat like a branch or a pitchfork.
	lanceolate	lanceolata	entire leaf	Long, wider in the middle, shaped like a lance tip.
	laminar			Flat (like most leaves)
	linear	linearis	entire leaf	Long and very narrow like a blade of grass.
	lobed	lobata	entire leaf	Being divided by clefts, may be pinnately lobed or palmately lobed.
	lorate	loratus	entire leaf	Having the form of a thong or strap.
	lyrate		entire leaf	Shaped like a lyre, pinnately lobed leaf with an enlarged terminal lobe and smaller lateral lobes.
	mucronate		leaf tip	Ending abruptly in a small sharp point as a continuation of the midrib.[3]
	multifid	multi + findere	entire leaf	Cleft into many parts or lobes.
	obcordate	obcordata	entire leaf	Heart-shaped, stem attaches at the tapering end.
	oblanceolate	oblanceolata	entire leaf	Much longer than wide and with the widest portion near the tip, reversed lanceolate.
	oblique		leaf base	Asymmetrical leaf base, with one side lower than the other
	oblong	oblongus	entire leaf	Having an elongated form with slightly parallel sides, roughly rectangular.
	obovate	obovata	entire leaf	Teardrop-shaped, stem attaches to the tapering end; reversed ovate.
	obtrullate		entire leaf	Reversed trullate, the longer sides meet at the base rather than the apex.
	obtuse	obtusus	leaf tip	Blunt, forming an angle > 90°.
	orbicular	orbicularis	entire leaf	Circular.
	ovate	ovata	entire leaf	Oval, egg-shaped, with a tapering point and the widest portion near the petiole.
	palmate	palmate	entire leaf	Palm-shaped, i.e. with lobes or leaflets stemming from the leaf base.[4]
	palmately lobed	palmate	entire leaf	Consisting of or lobes[5] radiating from the base of the leaf.
	palmatifid	palma + findere	entire leaf	Palm-shaped, having lobes with incisions that extend less than half-way toward the petiole.
	palmatipartite	palma + partiri	entire leaf	Having lobes with incisions that extend over half-way toward the petiole.
	palmisect	palma + secare	entire leaf	Having lobes with incisions that extend almost up, but not quite to the petiole.
	pandurate		entire leaf	Fiddle-shaped; obovate with a constriction near the middle.
	pedate	pedata	entire leaf	Palmate, with cleft lobes.[6]
	peltate	peltata	stem attachment	A round leaf where the petiole attaches near the center. An example would be a lotus leaf.
	perfoliate	perfoliata	stem attachment	With the leaf blade surrounding the stem such that the stem appears to pass through the leaf.
	perforate	perforata	leaf surface features	Many holes, or perforations on leaf surface. Compare with fenestrate.
	pinnately lobed	pinna + lobus	entire leaf	Having lobes pinnately arranged on the central axis.
	pinnatifid	pinna findere	entire leaf	Having lobes with incisions that extend less than half-way toward the midrib.
	pinnatipartite	pinnatus partiri	entire leaf	Having lobes with incisions that extend more than half-way toward the midrib.
	pinnatisect	pinnatus + sectum	entire leaf	Having lobes with incisions that extend almost, or up to midrib.
	plicate	plicatus, plicata	3-d shape	Folded into pleats, usually lengthwise, serving the function of stiffening a large leaf.
	reniform	reniformis	entire leaf	Shaped like a kidney: an oval with an inward curve on one side.
	retuse		leaf tip	With a shallow notch in a round apex.
	rhomboid or rhombic	rhomboidalis	entire leaf	Diamond-shaped.
	rounded	rotundifolia	leaf tip or base	Circular, no distinct point.
	semiterete		3-d shape	Rounded on one side, but flat on the other.
	sagittate	sagittata	entire leaf	Arrowhead-shaped with the lower lobes folded, or curled downward
	spatulate	spathulata	entire leaf	Spoon-shaped; having a broad flat end which tapers to the base
	spear-shaped		entire leaf	see hastate.
	subobtuse	subobtusa	leaf tip or base	Somewhat blunted, neither blunt nor sharp
	subulate	subulata	leaf tip	Awl-shaped with a tapering point
	terete		3-d shape	Circular in cross-section; more or less cylindrical without grooves or ridges.
	trullate		entire leaf	Shaped like a bricklayer's trowel
	truncate	truncata	leaf tip or base	With a squared-off end
	undulate	undulatus	3-d shape	Wave-like
	unifoliate	unifoliata	compound leaves	With a single leaf

Edge (margin)

Leaf margins are frequently used in visual plant identification due to the fact that they are usually consistent within a species or group of species, the leaf edges are also an easy to observe characteristic which makes them even more useful for identification. Edge and margin are both interchangeable in the sense that they refer to the outside perimeter of a leaf.

Image	Term	Latin	Description
	entire	Forma integra	Even; with a smooth margin; without toothing
	ciliate	ciliata	Fringed with hairs
	crenate	crenata	Wavy-toothed; dentate with rounded teeth
	crenulate	crenulate	Finely crenate
	crisped		curly
	dentate	dentata	Toothed. May be coarsely dentate, having large teeth, or glandular dentate, having teeth which bear glands
	denticulate	denticulata	Finely toothed
	doubly serrate	duplicato-dentata	Each tooth bearing smaller teeth
	serrate	serrata	Saw-toothed; with asymmetrical teeth pointing forward
	serrulate	serrulata	Finely serrate
	sinuate	sinuosa	With deep, wave-like indentations; coarsely crenate
	lobate	lobata	Indented, with the indentations not reaching the center
	lobulate	lobulate	With small lobes
	undulate	undulata	With a wavy edge, shallower than sinuate
	spiny or pungent	spiculata	With stiff, sharp points such as thistles

Leaf folding

Leaves may also be folded or rolled in various ways. The folding of leaves within a bud is vernation, also called ptyxis.

Image	Term	Latin	Description
	carinate or keeled	carinata	with a longitudinal ridge
	conduplicate		folded upwards, with the surfaces close to parallel
	involute		rolled upwards (towards the adaxial surface)
	plicate	plicata	with parallel folds
	reduplicate		folded downwards, with the surfaces close to parallel
	revolute		rolled downwards (towards the abaxial surface)

See also

• Glossary of botanical terms
• Cladophylls are leaf-like petioles
• Leaf size
• Sinus
• Leaflet (botany) and Rachis
• Petiole (botany) and Plant stem
• Phylloclades are flattened stems that resemble leaves
• Pinnation

References

1. Radford, A. E., W. C. Dickison, J. R. Massey, C. R. Bell (1976), "Phytography - Morphological Evidence", Vascular Plant Systematics, Harper and Row, New York
2. Also used to describe compound leaves with finger-like leaflets.
3. Mucronate, Answers.com, from Roget's Thesaurus.
4. "palmate (adj. palmately)". GardenWeb Glossary of Botanical Terms.
5. "palmate (adj. palmately)". GardenWeb Glossary of Botanical Terms.
6. "Pedate leaf". Retrieved February 24, 2014.

Bibliography

• "Leaves"., in Massey & Murphy (1996)
• "Shapes"., in Massey & Murphy (1996)
• Massey, Jimmy R.; Murphy, James C. (1996). "Vascular plant systematics". NC Botnet. University of North Carolina at Chapel Hill. Retrieved 19 January 2016.

External links

• The Description of Leaves, University of Rochester
• Fairchild Tropical Botanic Garden
• Vplants
• Botany 115
• The seed site