Glossary of leaf morphology

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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[edit]

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
Leaf morphology Bifoliolate.png bifoliolate Having two leaflets[1]
geminate
jugate
Leaf morphology Bigeminate.png bigeminate Having two leaflets, each leaflet being bifoliolate
Leaf morphology bipinnate.png bipinnate bipinnata The leaflets are themselves pinnately-compound; twice pinnate
Leaf morphology Biternate.png biternate With three components, each with three leaflets
Leaf morphology odd pinnate.png imparipinnate With an odd number of leaflets, pinnate with a terminal leaflet (the opposite of paripinnate)
odd-pinnate
Leaf morphology even pinnate.png paripinnate Pinnate with an even number of leaflets, lacking a terminal leaflet (the opposite of imparipinnate)
even-pinnate
Leaf morphology Palmately compound.png 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)
Leaf morphology trifoliolate.png ternate ternata With three leaflets
trifoliate trifoliata
trifoliolate trifoliolata
Leaf morphology tripinnate.png tripinnate tripinnata Pinnately compound in which each leaflet is itself bipinnate

List of leaf (or leaflet) shapes[edit]

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
Leaf morphology acicular.png acicular acicularis entire leaf Slender and pointed, needle-like.
Leaf morphology acuminate.png acuminate acuminata leaf tip Tapering to a long point in a concave manner.
Leaf morphology Acute.png acute leaf tip or base Pointed, having a short sharp apex angled less than 90°.
Leaf morphology Apiculate.png apiculate apiculatus leaf tip Tapering and ending in a short, slender point.
Leaf morphology aristate.png aristate aristata leaf tip Ending in a stiff, bristle-like point.
Leaf morphology Attenuate.png 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.
Leaf morphology base auriculate.png auriculate leaf base Having ear-shaped appendages near the petiole.
asymmetrical entire leaf With the blade shape different on each side of the midrib.
Leaf morphology Caudate.png caudate leaf tip Tailed at the apex.
Leaf morphology cordate.png cordate cordata entire leaf Heart-shaped, with the petiole or stem attached to the notch.
Leaf morphology cuneate.png cuneate cuneata leaf base Triangular, wedge-shaped, stem attaches to point.
cuspidate leaf tip With a sharp, elongated, rigid tip; tipped with a cusp.
Leaf morphology deltoid.png deltoidor deltate deltoidea entire leaf Shaped like Greek letter Delta, triangular, stem attaches to side.
Leaf morphology digitate.png digitate digitata entire leaf With finger-like lobes, similar to palmate.[2]
Leaf morphology elliptic.png elliptic elliptica entire leaf Oval, with a short or no point.
Leaf morphology ensiforme.PNG ensiform ensiformis entire leaf Shaped like a sword, long and narrow with a sharp pointed tip.
Leaf morphology apex emarginate.png emarginate leaf tip Slightly indented at the tip.
Leaf morphology falcate.png falcate falcata entire leaf Sickle-shaped.
Leaf morphology Fenestrate.png fenestrate fenestrata Large openings through the leaf, see perforate. Sometimes use to describes leaf epidermal windows.
filiform filiformis entire leaf Thread- or filament-shaped.
Leaf morphology flabelate.png flabellate flabellata entire leaf Semi-circular, or fan-like.
Leaf morphology hastate.png 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.
Leaf morphology lanceolate.png lanceolate lanceolata entire leaf Long, wider in the middle, shaped like a lance tip.
laminar Flat (like most leaves)
Leaf morphology linear.png linear linearis entire leaf Long and very narrow like a blade of grass.
Leaf morphology lobed.png lobed lobata entire leaf Being divided by clefts, may be pinnately lobed or palmately lobed.
Leaf morphology Lorate.png lorate loratus entire leaf Having the form of a thong or strap.
Leaf morphology Lyrate.png lyrate entire leaf Shaped like a lyre, pinnately lobed leaf with an enlarged terminal lobe and smaller lateral lobes.
Leaf morphology Mucronate.png mucronate leaf tip Ending abruptly in a small sharp point as a continuation of the midrib.[3]
Leaf morphology multifide.svg multifid multi + findere entire leaf Cleft into many parts or lobes.
Leaf morphology obcordate.png obcordate obcordata entire leaf Heart-shaped, stem attaches at the tapering end.
Leaf morphology oblanceolate.png oblanceolate oblanceolata entire leaf Much longer than wide and with the widest portion near the tip, reversed lanceolate.
Leaf morphology oblique.png oblique leaf base Asymmetrical leaf base, with one side lower than the other
Leaf morphology oblong.png oblong oblongus entire leaf Having an elongated form with slightly parallel sides, roughly rectangular.
Leaf morphology obovate.png 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.
Leaf morphology obtuse.png obtuse obtusus leaf tip Blunt, forming an angle > 90°.
Leaf morphology orbicular.png orbicular orbicularis entire leaf Circular.
Leaf morphology ovale.png ovate ovata entire leaf Oval, egg-shaped, with a tapering point and the widest portion near the petiole.
Leaf morphology palmate.png palmate palmate entire leaf Palm-shaped, i.e. with lobes or leaflets stemming from the leaf base.[4]
Palmatilobé.svg palmately lobed palmate entire leaf Consisting of or lobes[5] radiating from the base of the leaf.
Palmatifide.svg palmatifid palma + findere entire leaf Palm-shaped, having lobes with incisions that extend less than half-way toward the petiole.
Palmatipartite.svg palmatipartite palma + partiri entire leaf Having lobes with incisions that extend over half-way toward the petiole.
Palmatiséquée.svg palmisect palma + secare entire leaf Having lobes with incisions that extend almost up, but not quite to the petiole.
Leaf morphology pandurate.png pandurate entire leaf Fiddle-shaped; obovate with a constriction near the middle.
Leaf morphology pedate.png pedate pedata entire leaf Palmate, with cleft lobes.[6]
Leaf morphology peltate.png peltate peltata stem attachment A round leaf where the petiole attaches near the center. An example would be a lotus leaf.
Leaf morphology attachment connate-perfoliate.png perfoliate perfoliata stem attachment With the leaf blade surrounding the stem such that the stem appears to pass through the leaf.
Leaf morphology Perforate.png perforate perforata leaf surface features Many holes, or perforations on leaf surface. Compare with fenestrate.
Pennatilobé.svg pinnately lobed pinna + lobus entire leaf Having lobes pinnately arranged on the central axis.
Pennatifide.svg pinnatifid pinna findere entire leaf Having lobes with incisions that extend less than half-way toward the midrib.
Pennatipartite2.svg pinnatipartite pinnatus partiri entire leaf Having lobes with incisions that extend more than half-way toward the midrib.
Pennatiséquée.svg 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.
Leaf morphology reniform.png reniform reniformis entire leaf Shaped like a kidney: an oval with an inward curve on one side.
Leaf morphology apex retuse.png retuse leaf tip With a shallow notch in a round apex.
Leaf morphology rhomboid.png rhomboid or rhombic rhomboidalis entire leaf Diamond-shaped.
Leaf morphology apex rounded.png rounded rotundifolia leaf tip or base Circular, no distinct point.
semiterete 3-d shape Rounded on one side, but flat on the other.
Leaf morphology spear-shaped.png sagittate sagittata entire leaf Arrowhead-shaped with the lower lobes folded, or curled downward
Leaf morphology spatulate.png spatulate spathulata entire leaf Spoon-shaped; having a broad flat end which tapers to the base
Leaf morphology hastate.png spear-shaped entire leaf see hastate.
Leaf morphology subobtuse.png subobtuse subobtusa leaf tip or base Somewhat blunted, neither blunt nor sharp
Leaf morphology subulate.png 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.
Leaf morphology trullate.png trullate entire leaf Shaped like a bricklayer's trowel
Leaf morphology truncate.png 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)[edit]

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

Leaf folding[edit]

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)
Palm leaf washingtonia robusta.jpg plicate plicata with parallel folds
reduplicate folded downwards, with the surfaces close to parallel
Ledum groenlandicum.jpg revolute rolled downwards (towards the abaxial surface)

See also[edit]

References[edit]

  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[edit]

External links[edit]