1.
HABITAT: The surrounding environment of a plant
v Mesophytes
v Xerophytes
v Hydrophytes
2.
HABIT: Characteristic form or bodily
appearance of an organism.
A) Herbs, Shrubs, Trees.
Herb
: Small plants with soft stems
are called herbs.
Shrub:
Shrubs are mostly larger than herbs. They give rise to woody branches
from the soil level to form bushy plants.
Trees: Trees are large, woody with
prominent main trunk, which normally give rise to many branches.
3.
ROOT: Underground part of the plant body.
v Tap
root : A
primary root developing from the radical of the embryo.
v Adventitious
root : Root developing from any part of
the plant body except the radical.
4.
STEM: Aerial part of the plant body.
A) Texture:
v Herbaceous:
Non-woody.
v Woody :
Hard in texture.
B) Types of stems
a) Aerial/Underground:
v Aerial :
Remains above the ground in the air.
v Underground:
Remains below the ground.
b) Erect/weak:
v Erect : A rigid and strong stem growing upright in
position.
v Weak
: Not strong enough to keep itself in a upright position. They are three types
C)
Form :
v Cylindrical:
Circular in transverse section.
v Angular : Showing many angles (Tri, Quadra, Pent
angular)
D)
Interior:
v Solid : A stem having filled interior.
v Fistular
: A stem having hollow interior.
E)
Surface:
v Glabrous:
Without hairs (or) smooth.
v Hairy : Covered with hairs.
v Spiny : Covered with prickly spines.
5.
LEAF : Leaves are the lateral, exogenous
appendages developed from the nodes of a shoot system.
A) Insertion:
Position of leaf in a plant body.
v Radical:
Leaves born on an underground reduced stem.
v Cauline:
Leaves born on the main stem.
v Ramal
: Leaves born on the lateral branches.
B)
Phyllotaxy: The mode of
arrangement of leaves on the stem or branch is called “Phyllotaxy”.
1) Alternate:
Single leaf arising at each node and alternate with each other.
2) Opposite: Two leaves are
present at a node opposite to one another.
It is of two types.
a) Opposite decussate : A Pair of opposite leaves at successive
nodes are present at
right
angles to each other.
b) Opposite superposed: A
Pair of opposite leaves at successive nodes are arranged
one above the other in the same plane.
3) Whorled : More than two leaves at each node as a whorl.
4) Leaf mosaic: Older leaves present at the lower nodes of the stem
possess longer petioles with
bigger lamina
and the young leaves of upper nodes bear shorter petioles with
smaller lamina.
Alternate Opp.
deccusate opp.superposed
Whorled
C)
Leaf attachment:
Petiolate or Sessile.
1. Petiolate: Leaf base situated on
the stalk or petiole.
v Pulvinous:
Swollen petiole base.
v Sheathing
: Leaf base is broad and surrounds stem
2. Sessile: Leaf without stalk or
petiole.
D)
Type of leaf :
1. Simple:
The leaf having simple undivided lamina.Eg: Mango.
2. Compound:
The leaf lamina is completely divided into many segments called leaf lets or
pinnas. It is of two types
a) Pinnately compound : The leaf let’s develop on the lateral sides
of the rachis.
v Uni-pinnately
compound: The leaflets directly born on the primary rachis.
Paripinnate : With even pair of leaflets. Eg: Tamarindus.
Imparipinnate:
With odd number of leaflets. Eg: Margosa.
Paripinnate Imparipinnate
v Bi-pinnately
compound: The primary rachis divided once and produce secondary rachii.
The leaflets develop on secondary rachii.Eg: Delonix.
v Tri-pinnately
compound: The rachis divides twice and produces secondary and tertiary
rachii. The leaflets develop on the tertiary rachii. Eg:Moringa.
v Decompound
leaf : Primary rachis divides many times without
any definite order.
The lamina is dissected into many units. Eg:
Coriandrum.
Bi pinnately
leaf Tri pinnately
compound Decompound
b) Palmately compound:
Leaflets are arranged at the tip of the petiole.
v Unifoliate
: With a single leaflet. Eg: Citrus.
v Bifoliate
: With two leaflets. Eg:Hadwickia.
v Trifoliate
: With three leaflets. Eg:Oxalis.
v Tetrafoliate:
With four leaflets. Eg:Marsilea.
v Pentafoliate:
With five leaflets. Eg:Gynandropis.
v Multifoliate
: With many leaflets. Eg: Ceiba.
Unifoliate Bifoliate Trifoliate
Tetrafoliate Pentafoliate Multifoliate
E) Stipules: Stipules are the
small lateral appendages present on either side of the leaf base.
v Stipulate : Stipules are present on either side of
leaf base.
v Exstipulate:
Stipules are absent
F) Shapes of leaves:
The
shape of lamina is the description of its form. It has various shapes.
v Acircular
: Needle shaped. Eg: Pinus
v Linear : Long
and slightly broader. Eg: Grasses
v Lanceolate : Shaped
like lance. Eg: Nerium
v Orbicular : More
or less circular. Eg: Lotus
v Elliptical :
Like an ellipse. Eg: Vinca
v Ovate : Egg shaped. Eg: Hibiscus
v Spathulate : Spoon like. Eg: Euphorbia
v Oblique : Lamina with unequal halves. Eg: Margosa
v Oblong : More or less rectangular. Eg: Banana
v Reniform
:
Kidney shaped. Eg: Hydrocotyle
v Cordate
: Heart shaped (with a deep notch at the base). Eg: Betel vine
v Saggitate
: Shaped like an arrow head.
Eg: Saggitaria
v Hastate :
Like saggitate but the two basal lobes are directed outwards. Eg: Ipomea
v Lyrate :
Shaped like a lyre. Eg: Mustard
v Centric :
Hollow and cylindrical. Eg: Onion
v Cuneate :
Wedge shaped. Eg: Pistia
v Obovate : Oval but slightly broader at the apex
than at the base Eg: Cassia
v Deltoid : Triangular/Delta shape. Eg: Abutilon
G)
Margin of Leaf:
The
margin of the lamina may be of different types
v Entire :
Smooth margin. Eg: Mango
v Repand
: When the margin is wavy. Eg: Polyalthia
v Serrate : Saw like margin. Eg: Margosa
v Spiny :If the margin is spiny. Eg: Argemone
v Crenate
: Margin with rounded teeth. Eg: Bryophyllum
v Dentate
: Large pointed teeth like margin. Eg: Water lily
H)
Apex of Leaf:
The apex of the leaf lamina shows
variations in different plants
v Acute : When
the apex is narrow and pointed. Eg: Mango.
v Acuminate
: If the apex is drawn out into a long
tapering tail. Eg: Ficus religiosa.
v Obtuse
:
When the apex is round. Eg: Banyan.
v Mucronate : Round
apex with sharp pointed tip. Eg: Vinca.
v Cuspidate
: When
the apex is spinous. Eg: Date palm.
v Tendrillar
: When the apex form a tendril. Eg: Gloriosa.
v Cirrhose
: When the mucronate apex ends with fine
thread like structures.eg: Banana.
v Truncate
: If the apex is abruptly cut with
across. Eg: Paris
v Retuse
: If the obtuse apex
slightly notched. Eg: Pistia.
v Emarginated
:If the obtuse apex is deeply notched. Eg: Bauhinia.
I)
Surface of Leaf:
The surface of the leaf lamina may be
v Glabrous
:
Smooth and with out hairs. Eg: Mangifera
v Glaucus : Covered
by waxy coating with white tinge.
Eg: Calotropis
v Scabrous : Rough surface. Eg: Ficus
v Viscose
: Sticky surface. Eg: Cleome
v Pubescent
: Covered with soft and wooly hair. Eg:
Tomato
v Pilose : Covered
with long distinct scattered hairs. Eg: Grewia
pilosa
v Hispid
: Covered with long rigid hairs. Eg:
Cucurbita
v Spinous : Covered with small spines. Eg: Solanum xanthocarpum
J)
Venation:
The arrangement of veins in the lamina of
a leaf is called venation In
angiosperms there exists two types
of venation. They are
v Reticulate: vein lets are irregularly distributed forming
a network.
v Unicostate(Pinnate):
Having single prominent mid rib. Eg:Mangifera.
v Multicostate(Palmate)
: Having more than one prominent veins arisig at the apex of petiole
a)
Convergent :Veins run
from base to apex in a curved manner Eg:
Zizyphus.
b) Divergent :Prominent veins arising from the tip of petiole diverges from
one another towards margin of leaf Eg: Cucurbita.
Simple Pinnate Palmate
v Parallel : Veins run parallel to each other , network
is not found
v Unicostate
(Pinnate) : Having single prominent vein that gives off
many lateral veins which
run
parallel
towards margin Eg: Banana.
v Multicostate
(Palmate) : Having more than one prominent veins
a) Convergent: Prominent veins
arising from the base of a leaf blade run parallel
towards apex Eg: Grass
b)Divergent: Prominent veins
arising from the tip, of petiole diverge towards the
margin of
leaf blade in more or less parallel manner .Eg: Borassus.
Simple Pinnate Palmate
K)
Texture of Leaf:
The texture of leaf lamina also varies in
different species
v Herbaceous
: When the lamina is thin and soft
v Coriaceous : When the lamina is leathery
v Succulent : When the lamina is thick ,soft and juicy
v Hygrophytic
: When the lamina is very thin , membranous and spongy
6. INFLORESCENCE:
Specialized stalk bearing variable number of flowers is called inflorescence.
a)
Position of Inflorescence:
v Terminal:
Developed from the apices of Main stem Eg: Crotalaria.
v Axillary:
Developed in the axils of leaf Eg: Hibiscus
v Intercalary:
Borne at internodes Eg:Callistemon
v Cauliflory:
Flowers are formed directly on old stems. Eg: Polyalthia
b) Type of inflorescence:
1)
Racemose inflorescence: Indefnite growth of peduncle and flowers are arranged
acropetally
v Simple
raceme: Simple unbranched peduncle produce many pedicellate , bracteate flowers
in acropetal manner. Eg: Crotalaria.
v Compound
raceme or Panicle: Peduncle is branched, each branch is a simple raceme Eg: Mangifera.
v Simple
Corymb: All the flowers on a peduncle are arranged in acropetal manner and are
brought more or less to the same height.
Eg: Cassia.
v Compound
Corymb: Peduncle is branched, each branch is a simple corymb.Eg: Cauliflower.
v Simple
Umbel: Many pedicellate flowers arise from the apex of the peduncle. Eg:Allium.
v Compound
Umbel: Peduncle is branched, each branch produces a simple umbel at its
apex Eg: Coriandrum.
v Spike:
A simple raceme with sessile flowers
Eg:
Amaranthus.
v Compound
Spike: Compound spike has branched peduncle with each branch, a spikelet. The
axis of the spikelet is called rachilla and form bottom sterile bracts called
glumes, above them fertile bracts bearing flowers called lemma are present. The
axis of flower bears reduced bracteoles called palea and essential organs are
arranged above the reduced perianth lobes called lodicules. This inflorescence
is a characteristic feature of the family Poaceae.
v Catkin:
A spike inflorescence with weak
,drooping peduncle. Eg: Acalypha
v Simple
Spadix: A spike inflorescence with fleshy peduncle covered by a large spathe (a
modification of bract) Eg: Colocasia.
v Compound
Spadix: Peduncle is branched covered by spathe Eg: Cocos.
v Head: Peduncle is condensed into a flattened disc
called receptacle. Flowers are arranged in centripetal manner
A) Homogamous
head :- Inflorescence with only one type
of florets i.,e ray (or)disc florets
B) Heterogamous
Head :- Inflorescence with disc and ray florets.
2) Cymose: Growth of the peduncle is condensed, with
definite number of flowers
v Solitary
cyme: It is the simple cymose inflorescence. The axis bears only single flower
at its apex.
Eg: Hibiscus rosa sinensis.
v Simple
cyme or cymule : Inflorescence axis terminates into single flower which in turn
bears two
lateral flowers. A three flowered inflorescence is formed. Eg: Jasmine.
v Monochasial
cyme: Inflorescence axis terminates
into a flower and produce only one branch from
its bract
a)Helicoids cyme: Monochasial cyme in which the successive
lateral branches develop only on
one side in a spiral manner. Eg: Hamelia.
b) Scorpoid cyme : Monochasial
cyme in which the successive lateral branches develop in a zig
zag
manner. Eg: Heliotropium.
v Dichasial
cyme : In this type after the peduncle terminates into a
flower the inflorescence axis
produces two
lateral branches and this type of branching continues so it is
called
dichasial cyme. Eg: Clerodendron.
v Polychasial
cyme : After the peduncle terminating
into a flower, the inflorescence axis
produces
many lateral branches , hence it is called polychasial cyme. Eg: Nerium.
3) Special type of inflorescence: Due to some modification in some inflorescence
the opening and arrangement
of flowers remains
special
v Verticillaster
: This type of inflorescence consists of flowers arising in the
axils of leaves arranged
oppositely
to each other. At every node in
the axil of leaves flowers develops
initially into
dichasial cyme and lateral into monochasial cyme. The flowers
are
sessile and axes are so short that flowers are crowded
round the node like a false whorl
(Verticel) hence it
is called vertcillaster. Eg: Leucas
v Cyathium
:
It is a single flower like inflorescence. It is covered by a deep cup like involucres
of
bracts with
external nectaries at the centre of this cup there is a single female flower
encircling this
female flower many male flowers are arranged in scorpoid cyme. Eg:
Euphorbia
v Hypanthodium : It is a fruit like inflorescence. The
inflorescence axis is condensed and forms a
fleshly, cup
like structure with an apical opening. Eg: Ficus.
Ø 7. FLOWER IN GENERAL :
A) Pedicel: Stalk of an individual
flower.
v Pedicellate:
A flower having a pedicel.
v Sessile:
A flower without a pedicel.
B) Bract: A modified leafy structure in the axis of which a flower
arises.
v Bracteate:
Flowers having bracts.
v Ebracteate:
Flowers without bracts.
C) Bracteole: A secondary bract
at the base of an individual flower.
v Bracteolate:
The flowers having bracteoles.
v Ebracteolate:
The flowers without bracteoles.
D) Presence of Floral Whorls:
v Complete:
A flower having all the four whorls i.e., calyx, corolla, androecium,
gynoecium.
v Incomplete:
A flower lacking one or more whorls.
E) Presence of Reproductive Organs:
v Bisexual:
A flower with both stamens and carpels.
v Unisexual:
A flower having only one sex organ i.e., either androecium (Staminate)or
Gynoecium (Pistillate)
F) Structural Symmetry:
v Actinomorphic
(regular): A flower with radial symmetry i.e., the parts of each whorl are
similar in size and shape; the
flower can be divided into two
equal
halves along more than one median longitudinal plane.
v Zygomorphic : A flower with bilateral symmetry i.e., the
parts of one or more
whorls are dissimilar ; the
flower can be divided into two equal
halves in only
one vertical plane. i.e., along the axis.
v Asymmetric
flower (irregular) : A flower which can not be cut into two equal halves in any
Plane. Eg: Orchids
G) Arrangement of Floral Organs:
v Acyclic
(spiral): The thalamus is conical or convex and the floral parts are arranged
spirally.
v Cyclic:
The floral organs are arranged in definite whorls.
v Hemi
cyclic( Spiro cyclic):Sepals and petals are arranged in regular whorls and
androecium
and Gynoecium are arranged spirally
H) Position of Floral Organs on Thalamus:
v Hypogynous:
A flower in which all the other organs i.e., calyx, corolla, androecium are
situated below
the level of ovary; ovary superior.
v Perigynous:
The floral organs viz, sepals, petals
and stamens are born and arise from around
the ovary and not beneath
it; ovary half superior or inferior.
v Epigynous:
The floral organs viz, sepals, petals and stamens are attached to the upper
part of
the ovary; ovary is
inferior.
I) Merosity: Number of floral parts in each whorl
v Dimerous : Floral parts in 2’s or multiple of two.
v Trimerous : Floral parts in 3’s or multiple of three.
v Tetramerous:
Floral parts in 4’s or multiple of four.
v Pentamerous:
Floral parts in 5’s or multiple of five.
J)
Nature of Perianth:
v A
chlamydeous: Perianth is absent and flowers appeared naked Eg: Euphorbia
v Chlamydeous:
Perianth is present. These are of two types.
a) Monochlamydeous: Flower with
perianth in one whorl Eg: Amaranthus
b) Dichlamydeous: Perianth is
distinguished in to calyx and corolla.
v Homochlamydeous:
Calyx and corolla are similar in all respects (size and
shape)
v Heterochlamydeous:
Calyx and corolla are dissimilar in all respects (size and
shape)
8.
FLOWER IN DETAIL:
A) Calyx: The outer whorl of flower
composed of the sepals.
a) Number of Sepals: 3 or 4 or 5 or
more
b) Cohesion:
v Polysepalous:
Sepals are free and separate.
v Gamosepalous:
Sepals are fused in whorl or in part.
c) Aestivation: Mode of
arrangement of sepals/petals in the bud.
B) Corolla: The second whorl of flower
composed of the petals.
a) Number of Petals: 3 or 4 or 5 or
more
b) Cohesion:
v Polypetalous:
Petals are free and separate.
v Gamopetalous:
Petals are fused in whorl or in part.
c) Aestivation: Mode of arrangement of sepals/petals in the bud.
v Valvate:
Sepals/petals are arranged closely with small gaps between them. Eg: Calyx of Hibiscus
v Twisted:
Sepals/petals overlap one another i.e., one margin of the sepal /petal is
covered by the next one Eg: Corolla of Datura
v Imbricate
: Out of five sepal/ petals one is completely outside, one completely inside,
and the
remaining three with
one margin inside and one margin outside.
v Ascendilingly
Imbricate: The odd petal is posterior and completely inside, one of the
anterior petal is completely out side.
The remaining
petals show regular overlapping in ascending manner. Eg:
Corolla of Caesalpinaceae
v Descendingly
Imbricate: The odd petal is posterior and completely outside. The anterior
Pair of petals
are completely inside. The remaining
petals how regular overlapping in the descending manner.
Eg: Corolla of Fabaceae
v Quincuntial: Out of five sepals/petals, two are completely
outside, two are completely inside,
The remaining has
one margin outside and one margin inside. Eg: Calyx of
Ipomea
C)
Androecium:
v It
is the third whorl of the flower
v Individual
units are called as stamens
v Each
stamen has a fertile anther and filament
a) Number
of stamens:
b)
Cohesion of stamens: Union among the
stamen
v Monadelphous: All filaments unite to form a single
bundle. Eg: Hibiscus
v Diadelphous : All filaments unite to form two bundles.
Eg: Tephrosia
v Polyadelphous:
Filaments unite to form many bundles. Eg
: Citrus
v Syngenesious:
Here the anthers of filaments are united and the filaments remain free.
Eg: Tridax
v Synandry:
Here all the stamens of flower unite completely to form a single structure.
Eg: Cucurbita
v Polyandrous:
Stamens are indefinite and free.
c)
Adhesion of Stamens: Stamens may unite
with other floral organs like sepals, petals or gynoecium.
v Epiphyllous: Stamens unite with perianth. Eg: Asparagus
v Episepalous:
Stamens unite with sepals.
v Epipetalous:
Stamens unite with petals. Eg: Datura
v Gynandrous:
Stamens unite with gynoecium .It is also called gynandrium or
Gynostegium. Eg: Calotropis.
d) Insertion of Stamens:
v Haplostemnous:
Stamens in one whorl are usually as many as the number of sepals or petals
v Diplostemonous:
Stamens in two alternating whorls, the members of outer whorl alternate with
petal
v Obdiplostemonous:
Stamens in two alternating whorls, the members of outer whorl opposite the
petals
v Polystemnous: Stamens in more than two whorls
e) Length of the Stamens: Stamens
in a flower are of the same length but in some cases it varies
accordingly.
v Didynamous:
Androecium has six stamens in which two are long and other two
are short.Eg: Ocimum.
v Tetradynamous: Androecium has 6 stamens arranged in two whorls.
The outer
two stamens
are short and inner four are longer. Eg: Brassica
TETRADYNAMOUS DIDYNAMOUS
f) Position of the Stamens:
v Inserted
stamens: in some flowers the filaments are shorter than the petals .so the
stamens remain within the flower. Eg: Datura
v Exerted
stamens: In some flowers the filament of stamens are longer than the petals.
Eg: Acacia Arabica
g) Length of stamens:
v Extrorse:
When the ventral surface of anther faces the petal and the condition is called
extrose
v Introrse:
When the ventral surface of anther faces the gynoecium called introse.
h) Number of Anther Lobes:
v Dithecous
anther: In this two anther lobe are
present. Eg: Datura
v Monothecous
anther: In this only one anther lobe is present. Eg: Hibiscus
i) Fixation of Anther: The filament is attached to anther in different
ways
v Basifixed:
the filament is attached to the baser of the anther. Eg: Datura
v Dorsifixed:
the filament is attached to the anther on the mid dorsal side. Eg: Hibiscus
v Adnate:
the filament is attached to the whole length at the back of the anther.Eg: Nelumbo
v Versatile: the apex of the filament is pointed and is
attached to the back of the anther at a point , so that the latter can swing
freely in any direction. Eg: Oryza sativa.
j) Dehiscence of Anther: At maturity the anther dehisces to liberate pollen
grains.
v Longitudinal:
the anther dehisces longitudinally. Eg: Datura
v Transverse:
the anther dehisces horizontally. Eg: Hibiscus
v Valvular
: the wall of the anther lobe dehisces like a valve. Eg: Cassytha
v Porous: the anther
lobes dehisce in the form of pores at their apices. Eg: Solanum
D) Gynoecium:
v The
innermost whorl of the flower
v Individual
unit are called as carpels
v Each
carpel has ovary, style and stigma
a)Number of Carpels :
v Monocarpellary:
Gynoecium with one carpel. Eg: Dolichos
v Bicarpellary : Gynoecium
with two carpels. Eg: Solanum
v Tricarpellary : Gynoecium
with three carpels. Eg: Allium
v Tetracarpellary: Gynoecium with four carpels. Eg: Oenothera
v Pentacarpellary: Gynoecium with five carpels. Eg: Hibiscus
v Multicarpellary: Gynoecium with many carpels.Eg: Annona
b) Fusion of Carpels: The
carpels of gynoecium may remain free or fused.
v Apocarpous: the carpels present on the thalamus remain free.
Eg: Annona
v Syncarpous:
the Carpels of the ovary are completely or partially fused. Eg: Hibiscus
c) Number of Locules :
v Unilocular : With
one locule. Eg: Dolichos
v Bilocular :
With two locules. Eg: Solanum
v Trilocular : With
three locules. Eg: Allium
v Tetralocular: With
four locules. Eg: Ipomea
v Pentalocular: With five locules. Eg: Hibiscus
v Multilocular: With
may locules. Eg: Abutilon
d) Position of the Ovary :
v Superior
: It is seen in hypogynous flowers. The
gynoecium is placed on the thalamus
v Inferior: It is seen in epigynous flowers.The thalamus
is deep cup like structure in which
gynoecium is placed.
e) Placentation: The mode
arrangement of ovules in the ovary is called placentation
v Marginal
placentation : The ovary is unilocular.
The ovules are borne on the ventral suture
of
ovary. Eg: Dolichos
v Parietal
placentation : The ovules are borne on the inner walls of the ovary that bears
incomplete
partitions. Eg: Brassica
v Axile
placentation: The ovules are attached to
central axis present in the bi to multilocular
ovary. Eg: Hibiscus
v Free
central placentation: This placentation is developed from the axile placentation
with
degradation of septa. Eg: Dianthus
v Basal
placentation: This is found in
unilocular ovary. The ovules are few or reduced to one
and
are borne on the base of the ovary. Eg: Tridax
v Superficial
placentation: It is found in multilocular ovary. Ovules develop all round the inner
surface of the septa.
Eg: Nymphaea
f) Style: It is a long stalk above the ovary
v Terminal: It arises from the apical part of the ovary.
Eg: Hibiscus
v Lateral : Style
arises from the lateral side of the ovary. Eg: Mangifera
v Gynobasic: Style arises from the base of the ovary in
between the four locules. Eg: Ocimum
g) Stigma: It is the terminal
end of the style which receives pollen grains
v Capitate : Rounded stigma
v Bifid
: Forked
v Feathery
: Faethers
v Discoid
: Disc shaped
v Dumbbell :
Dumbbell shaped
v Linear : Long
v Sticky :
With sticky fluid.
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