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Types of Root Systems Plants have three types of root systems: 1.) taproot, with a main taproot that is larger and
grows faster than the branch roots; 2.) fibrous, with all roots about the same size;
3.) adventitious, roots that form on any plant part other than the roots. Fibrous systems
are characteristic of grasses and are shallower than the taproot systems found on most
eudicots and many gymnosperms.
Modifications of Roots Roots are modified into different forms to perform specific functions other than their normal functions.
Modification in roots is found in both tap root system and adventitious root system.
Modification in root occurs when there occurs a permanent change in the structure of the root system.
This change in structure of the tap root or the adventitious root system is for carry out certain specific
functions additional to anchorage and absorption. The change in the structure of the roots is for
adaptation to their surrounding environment.
Tap Root Modifications Back to Top
Tap roots are modified in to different structures, these modified structures carry out specific functions like food storage. Such roots are referred to as modified tap roots. They are different types of modified tap roots like Fusiform, Napiform, Conical, Tuberous or tubercular roots, pneumatophores.
Fusiform : Fusiform is a modified tap root. The primary root of the system is swollen at the middle and
tapers gradually at both the ends forming a spindle shaped structure. Example of fusiform roots is radish.
Napiform : The base region of the root is swollen becoming almost spherical in shape, and then it
abruptly tapers towards the lower end, forming a tail-like structure. Example of Napiform roots are turnip
and beet.
Conical: In the conical form of root modification the roots are swollen and are broad at the base, the apex
part gradually tapers forming a con like structure like in carrot.
Tuberous or tubercular : In the case of tuberous roots, the roots are thick and fleshy. They do not form
any definite shape. Example: Sweet potato, yam.
Pneumatophores : The pneumatophore roots grow vertically up, they protrude out of water or marshy sol
like conical spikes. These roots occur in large number around the trunk of the tree. Pneumatophore roots
are many pores for breathing through which exchange of gases takes place for respiration. Example of
pneumatophores are Rhizophora.
Adventitious Root Modifications Back to Top
Adventitious roots are the roots that are produced from any portion of the plant other than the radicle. The
root system may be changed to different forms for special functions like storage, mechanical support and
vital functions.
A. For Storage Of Food
Tuberous root : The adventitious roots in this are grown from the nodes of the running stem. These roots are
modified are swollen into irregular forms and are known as tuberous roots. They are produced in single
number. Example: Sweet Potato.
Parts of a stem These are the basic elements of a plant stem and the organs (eg leaves and flowers) which extend from
it:
This is the role of each of the major stem parts:
Stem The term ’stem’ refers to the structure which provides support for the plant and connects the roots (which
draw up water and nutrients) to the leaves (which produce energy) and flowers (which are in charge of
reproduction). There can be one stem originating from the roots with lateral stems growing from it, many
different stems coming out from the roots, or a combination of the two. Where there is just one stem
coming from the roots of a woody perennial this is known as a ‘trunk’.
Branch/lateral growth/side shoot These different terms are all used to describe stems which come out of the main stem. Generally this
growth is slightly slimmer than the main stem or ‘trunk’ of the plant.
Node Nodes are areas of growth. These parts of the stem contain a lot of cells which are called ‘meristematic‘;
cells which actively divide to create lots of new cells. Nodes are where you will find buds, side shoots,
leaves and flowers growing. Nodes are important when propagating plants by stem cuttings.
Internode This is the space between two nodes. It is the area which extends to give the stem more length and,
therefore, the plant more height. It is also known as the ‘internodal’ area.
Axillary bud These are buds which form in the axils between a stem and a side shoot, or between a stem and a leaf.
These buds may remain dormant or may develop into a side shoot, leaf or flower.
Apical bud This type of bud is found at the tip of stems and denotes a strongly meristematic area, ie an area where
cells are actively dividing and, therefore, lengthening the stem. At these apical growth points there is a
build up of a hormone called auxin, which controls the growth. The heightened levels of auxin at the tips
of stems inhibits the axillary buds (this is called ‘apical dominance’) and is the reason why they often
remain dormant. When we prune plants we remove the apical buds, which encourages more growth from
the axillary buds. This is why plants often become more bushy with pruning .
Leaf The leaves are either sessile (growing directly out of the stem) or petiolate (growing on a stalk called a
petiole). Leaves grow out of nodes and the point where the leaf or petiole meets the stem is called the
leaf axil.
Pedicel and flower See ‘parts of a flower‘.
The internal structure of a stem varies depending on the type of plant. Its basic constituents are the
phloem and xylem vessels which form the plant’s transportation system, meristematic ‘cambium’ cells
which are actively dividing cells producing more phloem and xylem tissue, and cortex cells which fill in the
gaps between the other types of cells and can also store food or become meristematic (growing) in order
to repair damage to the stem.
In woody perennials, and some other plants, the ongoing production of phloem and xylem cells is
responsible for the thickening of the plant’s stems. This increase in width stretches and squashes the
epidermis, or ’skin’, of the stem, so the plant has to keep on producing new epidermal cells. The old, dead
cells build up and appear as bark on the outside of the stem. Tiny pores (which appear as spots on some
stems) called ‘lenticels’ allow gases (such as oxygen) to enter and leave the inside of the stem, used for
purposes such as respiration.
Stems can also be modified into many different forms, including:
Fasciculate root : The tuberous roots are developed from the base of the stem in cluster. Nodulose root :
The adventitious roots in this case arise from the underground stem. Some roots that are
slender become swollen near the apex and they form nodule like structures. Example: mango-ginger.
Moniliform or Beaded roots : In this case, the roots are swollen at frequent intervals. This formation gives a
beaded or moniliform type of appearance. This form of root formations is seen in many grasses, Basella, etc.
Annulated roots : This type of roots has ring-like swellings ina series and appears in the form of a number of
discs placed one above the other. Examples are Cephalis ipecacuanha (Ipeca).
B. For Mechanical Support
Prop roots : Here the plants have tap roots system. the horizontal branches of the stem of the plant gives rise
to aerial roots. These aerial roots hang vertically downwards. These roots on reaching the ground, they grow
and act like pillars. They provide mechanical support to the plant. Example Ficus bengalensis.
Stilt Roots : These plants have their own roots system like in screwpine. They are not strongly anchored tothe
soil. Hence, these plant develop adventitious roots from near the base of the stem. These roots grow obliquely
downwards. They act like stilt and they provide mechanical support to the plant. Example - the maize plant
produces adventitious roots form the lower nodes which also act in a similar way.
Climbing roots : This type of root system is found in climbers. Adventitious roots are developed from the
nodes and are aerial roots. These aerial roots twist and clasp the support and help in climbing. Example Betel,
Pothos, etc.
Clinging roots : This type of roots are seen in orchids. These roots arise from the stem base of the plant. They
enter crevices of the support to fix the epiphyte. They provide the plant with mechanical support.
Root buttresses : Some trees have great plant-like roots that radiate from the base of the stem of the tree. It
consists of partly root and partly stem. Example is Bombax.
C. For Vital Functions
Sucking roots or Haustoria : Cuscuta is a leafless, parasitic plant, it always grows in association with other
plants. The parasatic plant at the point of attachment with the host plant produces some knob like roots known
as haustoria which penetrate into the host plant and draws nourishment.
Epiphytic roots : are the plants like orchids that grow perched on tree branches. They attach themselves
firmly to the trunk of the tree by the aid of social roots known as climbing roots.
They also have aerial roots for absorbtion. These roots are fleshy and remain along with the clinging roots.
These roots have spongy tissues which absorb moisture from the atmosphere. They also have chlorophyll
pigment and photosynthesis takes place.
Floating roots: are found in aquatic plants. These roots develop from the nodes of the floating branches. The
roots are spongy and are colorless. These roots are present above the level of water. As these roots are
spongy and soft, they store air in them which help the plant in floating. They also help in respiration process.
Assimilatory roots : are normally non-green in color. The adventitious roots are developed from the branches
of the plant Tinospora cord folia. These branches are green in color and carry out photosynthesis, the roots
developed from this are known as assimilatory roots. The assimilatory roots are slender, long and in hanging
state.
Modification of Stems
The stem shows different modifications like root to perform some special functions like synthesizing the food materials, conducting water and mineral salts to the leaves, poliage to sunlight for photosynthesis etc., Depending on their nature they are of 3 typesas follows
Underground stem modification
Generally stems are present above the soil (aerial) but in some plants they grow below the soil which are called as underground or subterranean or geophyllous stems or stem modifications. They will store food materials and the well protected from herbivorous animals, by performing these functions they are also known asmultipurpose stem modifications.
These stems contains nodes, internodes, scale leaves axillary and terminal buds. Based on their growth and the storage of food materials they are of 4 types as follows:
Rhizome
It is the thickest underground stem which grows horizontally below the soil consisting of nodes and
internodes.
It is brown in colour and dorsiventral producing aerial branches and reproductive organs on the dorsal side and adventitious roots on the ventral side.
The nodes consists of scale leaves and branches arises from axillary buds (to store the food materials and maintains the horizontal growth) and the aerial branches of rhizome are called as scapes.
The vertical rhizome of this is known as root stock.
Examples: Ginger, Turmeric
Corm
The stem which grows vertically in the soil at a particular depth consisting of nodes and internodes.
The food materials are synthesized in aerial branches and stored by the stem. Hence it becomes tuberous.
Leaves are reduced to scale leaves and the axillary buds produced daughter corms and it consists of some
special roots are called as pull roots or contractile roots.
Example: Amorphophyllus, Colacasia
Stem tuber
In this, branches develops from the lower part of the stem and grows into the soil, the apices of these
branches stores food materials hence they will become tuberous which are known as stem tubers and can grow at any depth.
This is covered by a brown coloured layer periderm which bears many eyelike structures represents the nodes.
Each eye possesses a semi-lunar leaf scar which represents the position of scale leaf and also helps in
vegetative propagation.
The vegetative propagation through eyes is called sprouting.
Example: Potato, Helianthus
Bulb
It is a special type of underground stem which is reduce to biconvex dislike structure with number of
adventitious roots on its lower side and does not stores the food.
The leaves develop on the upper side of the disk and grow above the soil.
The leaf bases stores the food and water hence they will be fleshy.
The axillary buds produce daughter bulb and terminal bud is at the centre and develops aerial shoots producing inflorescence.
Depending on arrangement of scale leaves they are of two types as follows:
o Tunicated bulb: In this the leaf bases of scale leaves overlap one above the other in a
concentric circles and the entire bulb is covered by dry, membranous scale leaves called as tunica.
Example: Onion
o Scaly bulb or naked bulb or imbricate bulb: The scale leaves are fleshy which are loosely
arranged are called as cloves. It the leaf is covered by tunica and the bulb is not covered
with that, called as naked bulb. It the scale leaves are arranged in a group with shinning tunica, called as imbricate bulb. If the stem and leaf bases stores the food materials they appear in the form of solid bulbs.
Example: Tuberose, cloves ,Lilium
Sub-aerial stem modifications:
The stem which grows partly aerial and partly below the soil are called as sub-aerial stems which are specialized for vegetative propagation. They are of four typesas follows
Runners
In this, the stem creeps on the soil and the rooted at every node.
When the internodes break of nodes leads an independent life, such stems are known as runners which help in vegetative propagation.
Examples: Hydrocotyle, Oxalis
Stolons or walking stems
In this the slender branches arises from the base of the stem which grows obliquely downwards.
When these branches touch the soil they produce adventitious roots, called as stolons. It separated from the mother plant they leads an independent life.
Examples: Jasmine, Nerium
Suckers
In this underground branches grows obliquely upwards from the axillary buds of nodes present below the soil.
These branches produce adventitious roots on the ventral surface, called as suckers. If separated they leads an independent life.
Examples:Mentha,Chrysanthemum
Offsets
Stem is reduced to a disc like structure and the leaves from this grows in rosette manner.
The axillary buds of these leave develop into short and the slender branches of one Internodal length and grows horizontally above the water, called as offsets.
The apex of each set bears number of leaves on the upper side and the adventitious roots on its lower, if it breaks they leads an independent life.
Example: Pistia, Lemna
Aerial stem modifications
The stem which grows aerially consisting of vegetative parts a floral parts of plants growing in different environmental conditions and undergo modifications to perform various function are called as aerial stem modifications. They are of 6 typesare as follows
Tendrils
Some weak stemmed plants produce wiry, coiled and sensitive structures for the purpose of climbing, called as tendrils. They coil around the support and helps in climbing formed from the axillary or terminal buds.
Examples: Passiflora, Vitis vinifera
Thorns
These are hard, woody pointed structures which meant for protection develops either from axillary bud or terminal bud.
Examples: Duranta, Carissa
Hooks
These are woody, curved sensitive structure developed either from axillary or terminal bud.
Examples: Hugonia, Artobotrys
Phylloclades
In these plants leaves are modified into scale leaves or spines and man stem branches modifies into green leaf like structures to perform photosynthesis known asphylloclades or cladophylls.
Phylloclades which contains only one internode known as cladode.
Examples: Asparagus, Opuntia, casuarina
Tuberous stem
The aerial stem of the plants stores food materials and become tuberous known as tuberous stem.
Examples: Brassica, Bulbophyllum
Bulbils
`The plants consisting of vegetative and floral parts modified into condensed branches which stores food materials, these modified buds are known as bulbils.
Examples: Diascorea, Oxalis
The Parts of a Leaf
Most leaves have two main parts: (1) the blade and (2) the
petiole, or leafstalk. The leaves of some kinds of plants also
have a third part, called the stipules.
The Blade, or lamina, is the broad, flat part of the leaf. Photosynthesis
occurs in the blade, which has many green food-making cells. Leaf
blades differ from one another in several ways: (1) the types of edges, (2)
the patterns of the veins, and (3) the number of blades per leaf.
The Types of Edges. Almost all narrow, grasslike leaves and needles
leaves have a blade with a smooth edge, as do many broadleaf plants,
particularly those that are native to warm climates. The rubber plant, a
common house plant, is a good example of such a plant.
The leaves of many temperate broadleaf plants have small, jagged points
called teeth along the blade edge. Birch and elm trees have such leaves.
Some plants have hydathodes, tiny valvelike structures that can release
excess water from the leaf. The teeth of young leaves on many plants,
including cottonwood and pin cherry trees, bear tiny glads. These glands
produce liquids that protect the young leaf from plant-eating insects.
Some temperate broadleaf plants -- including sassafras trees and certain
mulberry and oak trees -- have lobed leaves. The edge of such a leaf
looks as if large bites have been taken out of it. This lobing helps heat
escape from the
leaf.
The Patterns of
the Veins. Veins
carry food and
water in a leaf.
They also support
the blade, much as the metal ribs support
the fabric of an open umbrella.
In most broad leaves, the veins form a
netlike pattern, with several large veins
connected by smaller ones. The smallest
veins supply every part of the blade with
water. They also collect the food made by the green cells.
There are two main types of net-vein patterns -- pinnate (featherlike) and palmate (palmlike or
handlike). Pinnately veined leaves have one large central vein, called the midrib, which extends
from the base of the blade to its tip. Other large veins branch off on each side of the midrib. The
leaves of beech, birch, and elm trees have such a vein pattern. A palmately veined leaf has
several main veins of about equal size, all of which extend from a common point at the base of
the blade. The vein patterns of maple, sweet gum, and sycamore leaves are palmate.
Narrow leaves and needle leaves are not net-veined. Narrow leaves have a parallel-vein pattern.
Several large veins run alongside one another from the base of the blade to the tip. Small
crossveins connect the large veins. Needle leaves are so small that they have only one or two
veins running through the center of the blade.
The Number of
Blades per Leaf. A
leaf with only one
blade is called
a simple leaf.
Apple and oak
trees, grasses, and
many other plants
have simple
leaves. A leaf with
more than one
blade is known as
a compound leaf.
The blades of a
compound leaf are
called leaflets.
The leaflets in a
compound leaf
may be arranged
in a pinnate or
palmate pattern. In pinnately compound leaves, the leaflets grow in two rows, one on each side
of a central stalk, called the rachis. Plants with pinnately compound leaves include ash and
walnut trees and garden peas. The leaflets in a palmately compound leaf all grow from the tip of
the leafstalk. Clover, horse chestnut trees, and many other plants have palmately compound
leaves.
A few plants -- including carrots, honey locust trees, and Kentucky coffeetrees -- have double
compound leaves, with each leaflet being divided into a number of still smaller leaflets.One
double compound leaf looks more like a group of twigs and leaves than like a single leaf.
The Petiole is the stemlike part of the leaf that joins the blade to the stem. Within a petiole are
tiny tubes that connect with the veins in the blade. Some of the tubes carry water into the leaf.
Others carry away food that the leaf has made. In many trees and shrubs, the petioles bend in
such a way that the blades receive the most sunlight, thus assuring that few leaves are shaded by
other leaves. The petiole also provides a flexible "handle" that enables the blade to twist in the
wind and so avoid damage.
In some plants, the petioles are much larger than the stems to which they are attached. For
example, the parts we eat of celery and rhubarb plants are petioles. In contrast, the leaves of
some soft-stemmed plants, particularly grasses, have no petioles.
The Stipules are two small flaps that grow at the base of the petiole of some plants. In some
plants, the stipules grow quickly, enclosing and protecting the young blade as it develops. Some
stipules, such as those of willows and certain cherry trees, produce substances that prevent
insects from attacking the developing leaf.
In many plants the stipules drop off after the blade has developed, but garden peas and a few
other kinds of plants have large stipules that serve as an extra food-producing part of the leaf.
Leaf venation
Illustrations by Marina Smelik
Leaf venation refers to the pattern of veins on the leaf. The veins supply the leaf with
water and minerals from the roots and transport materials from the leaf to the rest of
the plant. The vein pattern can be useful for plant identification when the pattern is
distinct and obvious, so only a few basic patterns will be used in this course.
LEAF VENATION PATTERNS
The primary vein is like the trunk on a tree. It is the widest vein on the leaf and starts
at the base of the leaf.
Secondary veins are like the main branches on a tree, they are smaller than the
primary vein.
There are two ways the secondaries may come off the primary. In one pattern,
illustrated on the left below, the secondaries come off of the primary vein all along the
length of the primary. In the second pattern, illustrated on the right below, secondaries
originate from at or near the base of the primary.
Leaf secondary veins all arising along entire length of primary vein.
Leaf secondary veins (at least some) arising at or near leaf base.
Secondary veins parallel to each other for their entire length, stay straight all the way
to the leaf margin.
Secondary veins parallel to each other for their entire length, curve upward as they
approach the leaf margin.
Leaf secondary veins not parallel to each other for their entire length, secondary
veins much-branched.
What's the Difference Between
Monocot & Dicot Leaves?
Traditionally all members of the class of
flowering plants have been regarded as
belonging to one of two subclasses: They were
either monocots or dicots. In our flower section
we have a special pageshowing differences
between monocot and dicot flowers, plus we
have another pageindicating that nowadays all
flowering plants aren't necessarily considered
either monocots or dicots.
Still, for our backyard purposes, thinking in
terms of monocots and dicots can be very
useful. For example, look at the big differences
distinguishing the leaves of most monocots and
dicots:
Dicots include nearly all our trees, bushes, vegetable-garden plants (not corn),
and most of our wildflowers (not irises and lilies). Dicot leaves are
usually net-veined, as in the close-up of the veins in a wild grape leaf at the
right. Notice how the larger veins are thicker and straighter, but as veins get
smaller and smaller, they tend to snake
around.
Monocots include all grasses and glasslike
plants, plus lilies, irises, amaryllises, and some
other plant types. Usually, but not always,
monocots possess parallel-veined leaves, as
typified in the simple blade of fescue grass
shown at the right. One example of a monocot
which does not have parallel-veined leaves is
the Trillium, several species of which are
common in moist American forests.
Leaf Attachments and Arrangements
leaf attachment
node - the point of leaf attachment to a stem.
internode - the region of the stem between leaves.
petiolate - a leaf attached to the stem by a petiole.
sessile - a leaf whose blade is attached directly to the stem, lacking a petiole.
clasping (or amplexicaul) - a sessile leaf with free bases partly or entirely surrounding the stem.
sheathing - with a tubular portion of the leaf blade surrounding the stem below the base.
decurrent - with leaf blade extended downward along the stem, forming vertical lines along the
stem.
ochreate - with stipules forming a thin tube around the stem above petiole.
perfoliate - with the bases of a single leaf fused around the stem, which appear to go through the
leaf blade.
connate-perfoliate - with bases of opposite leaves fused around the stem, which appear to go
through the leaf.
leaf arrangement
phyllotaxy - the arrangement of leaves on an axis.
2-ranked - arranged in 2 rows, one on either side of the stem or central axis.
alternate - an arrangement with 1 leaf attached at each node.
distichous - 2-ranked, with alternate leaves arranged on opposite sides of a stem, not spirally
arranged.
equitant - 2-ranked basal leaves, folded and flattened in the same plane, and with alternately
overlapping bases. New leaves emerge between the bases of the previous leaf, e.g.,
characteristic of irises (Iridaceae), Tofieldia (Tofieldiaceae), and Zingiberales.
opposite - an arrangement with 2 leaves attached at each node, on opposite sides of the stem.
decussate - with opposite leaves attached at right angles to the adjacent pairs of leaves.
whorled - an arrangement with 3 or > leaves attached at each node.
imbricate - with overlapping bases, the previous layer of leaves or scales overlapping younger
layers.
fascicle - 2 or > leaves grouped in a bundle and bound together at the base, derived from a
reduced shoot.
basal leaves - leaves arranged around the base of a stem.
rosette - a group of basal leaves.
cauline (or radical) leaves - leaves arranged along an aerial stem.
Leaf Apices
vernation - the arrangement of leaves in a bud.
circinate - a coiled vernation, with the frond apex in the centre of the coil; produced the
distinctive fiddlehead-shaped young leaves in ferns.
arrangement of stomates (pores in leaf epidermis, surrounded by guard cells and subsidiary
cells).
anomocytic - with no specialized subsidiary cells.
paracytic - with 2 specialized subsidiary cells surrounding the guard cells.
paratetracytic - with 4 specialized subsidiary cells surrounding the guard cells.
pericytic - with 1 specialized subsidiary cell surrounding the guard cells.
amphiparacytic - with 2 rows of 2 subsidiary cells surrounding the guard cells.
Attenuate a sharp-pointed apex with concave margins that form an angle less than (<) 45
degrees.
Acuminate a sharp-pointed apex with straight or convex margins that form an angle less than
(<) 45 degrees.
Acute an pointed apex with margins that form an angle between 45 and 90 degrees.
Obtuse a blunt apex with margins that form an angle greater than (>) 90 degrees.
Rounded an curved apex with margins that form a smooth arc.
Leaf Margin
LEAF MARGINS
The margin of a leaf is another name for the structure of the
leaf's edge.
There are many different variations, and they can be discovered
in this tutorial.
Caudate an attenuate apex with a slender tail-like appendage at the tip.
Cuspidate an acute apex with a stiff tip or cusp.
Mucronate with a small extension of the midrib barely extending beyond the blade apex.
Emarginate with a shallow depression at the apex, not exceeding ? of the distance to the centre
of the leaf blade.
Truncate a broad, flat apex, abruptly ending at right angles to the midvein.
Retuse a rounded summit with a shallow depression at the apex, not exceeding 1/16 of the
distance to the centre of the leaf blade.
Obcordate apex with prominent, rounded lobes, cut ? to ¼ of the distance to the centre of the
leaf blade.
Cleft apex divided into rounded or straight-margined lobes, cut ¼ to ½ of the distance to
the centre of the leaf blade.
Entire
A leaf that is smooth all the way around has an Entire margin
Crenate
If a leaf has a Crenate margin, then the edge of the leaf has blunt, rounded teeth.
Dentate
A Dentate margin is when a leaf has triangular, "tooth-like" edges.
Serrate
A Serrate margin is when a leaf has sharp, "saw-like" teeth.
An easy way to remember this margin is to picture this leaf as a similar to a serrated knife.
Doubly-Serrate
When a leaf is Doubly-Serrated, the "saw-like" teeth have even smaller teeth.
Mid-Margin Quiz
A quiz will load up below. If you find that you are not scoring very high, be sure to go back and review.
Serrulate
A leaf with a Serrulate margin is similar to Serrate, but has smaller, evenly-spaced teeth.
Incised
If a leaf has an Incised margin, it has deep, irregular teeth.
Lobed
When a leaf has a Lobed margin, the leaf has deep, rounded edges.
Sinuate
A Sinuate margin describes the sinuous, slighly wavy line along the edge of a leaf.
Undulate
When a leaf has an Undulate margin, it has extremely wavy lines along the edge.
Leaf Bases Attenuate
Leaf blade gradually tapers to a narrow base.
Cuneate
Leaf blade tapers to a narrow wedge-shaped base.
Acute
Leaf blade tapers to a sharp triangular-shaped base.
Cordate
Heart-shaped blade with a gently lobed base.
Rounded
Leaf blade has a rounded base.
Oblique
Each side of the leaf blade attaches at a different point on the petiole.
Truncate
Leaf blade is square at the base.
Auriculate
Leaf blade has lobes resembling ears.
Hastate
An arrow-shaped leaf with lobes that taper away from the petiole.
Sagittate
An arrow-shaped leaf with lobes that taper downward.
Leaf shape
Chart illustrating leaf morphology terms
Oddly pinnate, pinnatifid leaves (Apium graveolens, Celery)
Perfoliate bracts completely surrounding the plant stem (Lonicera sempervirens)
Simple, palmate-veined leaves
A single laciniate leaf ofAdenanthos sericeus
In botany, leaf shape is characterised with the following terms (botanical Latin terms in brackets):
Acicular (acicularis): Slender and pointed, needle-like
Acuminate (acuminata): Tapering to a long point
Acute: pointed, having a short sharp apex angled less than 90°
Aristate (aristata): Ending in a stiff, bristle-like point
Asymmetrical: With the blade shape different on each side of the midrib
Basal: arising from the crown, bulb, rhizome or corm, etc. as opposed to cauline
Bipinnate (bipinnata): Each leaflet also pinnate
Caudate: tailed at the apex
Cauline: borne on the stem as opposed to basal
Compound: Not simple; the leaf is broken up into separate leaflets, and the leaf blade is not continuous
Cordate (cordata): Heart-shaped, with the petiole or stem attached to the cleft
Cuneate (cuneata): Triangular, stem attaches to point
Deltoid (deltoidea) or deltate: Triangular, stem attaches to side
Digitate (digitata): Divided into finger-like lobes
Elliptic (elliptica): Oval, with a short or no point
Entire: having a smooth margin without notches or indentations
Falcate (falcata): Sickle-shaped
Fenestrate (fenestrata) "windowed" with holes (e.g. Monstera deliciosa or Aponogeton fenestralis), or window-like patches of translucent tissue. (cf Perforate)
Filiform (filiformis): Thread- or filament-shaped
Flabellate (flabellata): Semi-circular, or fan-like
Hastate, spear-shaped (hastata): Pointed, with barbs, shaped like a spear point, with flaring pointed lobes at the base
Laciniate: Very deeply lobed, the lobes being very drawn out, often making the leaf look somewhat like a branch or a pitchfork
Laminar: Flat (like most leaves)
Lance-shaped, lanceolate (lanceolata): Long, wider in the middle
Linear (linearis): Long and very narrow
Lobed (lobata): With several points
Mucronate: Ending abruptly in a sharp point[1]
Obcordate (obcordata): Heart-shaped, stem attaches to tapering point
Oblanceolate (oblanceolata): Top wider than bottom
Oblong (oblongus): Having an elongated form with slightly parallel sides
Obovate (obovata): Teardrop-shaped, stem attaches to tapering point
Obtuse (obtusus): With a blunt tip
Orbicular (orbicularis): Circular
Ovate (ovata): Oval, egg-shaped, with a tapering point
Palmate (palmata): Consisting of leaflets[2] or lobes[3] radiating from the base of the leaf.
Pedate (pedata): Palmate, with cleft lobes[4]
Pedatifid (pedatifida)[5]
Peltate (peltata): Rounded, stem underneath
Perfoliate (perfoliata): Stem through the leaves
Perforate (perforata): marked with patches of translucent tissue, as in Crassula perforata and Hypericum perforatum, or perforated with holes (cf "Fenestrate")
Pinnate (pinnata): Two rows of leaflets
Odd-pinnate, imparipinnate: Pinnate with a terminal leaflet
Paripinnate, even-pinnate: Pinnate lacking a terminal leaflet
Pinnatifid and pinnatipartite: Leaves with pinnate lobes that are not discrete, remaining sufficiently connected to each other that they are not separate leaflets.
Bipinnate, twice-pinnate: The leaflets are themselves pinnately-compound
Tripinnate, thrice-pinnate: The leaflets are themselves bipinnate
Tetrapinnate: The leaflets are themselves tripinnate.
Pinnatisect (pinnatifida): Cut, but not to the midrib (it would be pinnate then)
Serenoa repens showing pleated elliptic leaves of seedling and pleated palmate leaves of mature plant
Plicate (plicatus, plicata): folded into pleats, usually lengthwise, serving the function of stiffening a large leaf.
Pungent (spinose): Having hard, sharp points.
Reniform (reniformis): Kidney-shaped
Retuse: With a shallow notch in a broad apex
Rhomboid (rhomboidalis): Diamond-shaped
Round (rotundifolia): Circular
Sagittate (sagittata): Arrowhead-shaped
Simple: Leaf blade in one continuous section, not divided into leaflets (not compound)
Spear-shaped: see Hastate.
Spatulate, spathulate (spathulata): Spoon-shaped
Subulate (subulata): Awl-shaped with a tapering point
Subobtuse (subobtusa): Somewhat blunted, neither blunt nor sharp
Sword-shaped (ensiformis): Long, thin, pointed
Trifoliate (or trifoliolate), ternate (trifoliata): Divided into three leaflets
Tripinnate (tripinnata): Pinnately compound in which each leaflet is itself bipinnate
Truncate (truncata): With a squared off end
Undulate (undulatus): wave like
Unifoliate (unifoliata): With a single leaf