Plant morphology flower-converted

It discuss about what is plant morphology, calyx, types of calyx, types of sepals, corolla, types of corolla, Androecium, stamen, Gynoecium, Pistil, stalk, receptacle, Hypogyny, perigyny, epigyny, PERIANTH, PETALOID & SEPALOID PERIANTH, TYPES OF FLOWERS, CLASSIFICATION OF FLOWER, Insertion and Adhesion of Stamens Fixation of Anthers, Pollination, TYPES OF PLACENTA, Inflorescence & uses of flower

1. PLANT MORPHOLOGY -FLOWER
DR. C. BEULAH JAYARANI
M.Sc., M.A, M.Ed, M.Phil(Edn), M.Phil(ZOO), NET, Ph.D
ASST. PROFESSOR,
LOYOLA COLLEGE OF EDUCATION, CHENNAI -34

2. Introduction
•A flower is a reproductive
part of an Angiospermic
plant.
•It is considered to be a
modified shoot having
nodes and internodes and
the leaves are modified into
floral structures.
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3. Calyx
•It is the outermost whorl of the
flower.
•It is composed of leaf like green
sepals (sepaloid) that enclose a
developing bud.
•The sepals are essentially green in
colour but in some cases they are
coloured like petals. Such a
condition of calyx is called
petaloid.
•Being green, it also manufacture
food by photosynthesis.
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4. TYPES OF CALYX
•In some plants a whorl of green
sepals like structure is present
at the base of calyx called
epicalyx.Epicalyx is considered
a whorl of the bracteoles and
mostly found in the flowers of
family Malvaceae.
The calyxremains attached as
in tomato and brinjal. Such a
calyx is called a persistent calyx.
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5. TYPES OF SEPALS
Gamosepalous–the sepals are more
or less united.
Polysepalous–the sepals are free.
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6. Corolla
•This is the second whorl of
the flower and consists of a
number of petals.
•Together with the calyx, it
protects the inner essential
whorls, the stamens and
pistil.
•Petals are generally
brightly colouredand
sometimes fragrantwhich
make the flower to
become attractive.
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7. CONTD.,
•The corolla is generally large and showy
and assumes various shapes adapted to
attract insects and bring about pollination.
•A modified leaf or scale, typically small,
with a flower or flower cluster in its axil.
•Bractsare sometimes larger and more
brightly coloured than the true flower.
•The nectariesmake nectar. They are in the
centre of the flower. Nectar is a sweet
substance, which insects drink to give
them energy.
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8. Gamopetalous
–the petals are
united.
Polypetalous –
the petals are
free.
TYPES OF COROLLA
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9. Androecium
•It is the third whorl
of flower and is the
male reproductive
organconsisting of
stamens.
•Each stamen is made
of filament and
anther. The filament
supports anther at its
tip.
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10. STAMEN
The stamen (plural
stamina or stamens) is
the pollen-producing
reproductive organ of a
flower.
➢Filament-Supports
the Anther
➢Anther-Produces
Pollen Grains
The anther is usually
two lobed. Each lobe
has two pollen sacs.
Each pollen has two coats –
the exine (tough, cutinized
outer protective coat)and
theintine (thin delicate
cellulose layer lying
internal to the exine).
•Within the pollen sacs are
contained pollen grains.When
fully matured the pollen sacs
rupture to liberate pollen
grains.The pollen grains are
generally powdery particles
of different shapes and sizes.
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11. Gynoecium
•This is the fourth whorl of
flower and is the female
reproductive organ of the
flower.
•It occupies the central
position on the receptacle
and composed of ovary,
style and stigma and the
component parts are called
carpels.
•The pistil is composed of
one or more carpels.
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12. PISTIL
✓The ovule producing
part of a flower.
✓The ovary often
supports a long style,
topped by a stigma.
✓Stigma:The part of the
pistil where pollen
germinates.
✓The inner cavity may
contains one or more
chambers. Each
chamber contains one
or more ovules.
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13. STALK
•The tip of flower stalk may
be expanded to form a cup-
shaped receptacle
(thalamus).
The flower is commonly borne
on short or long stalk called
the pedicel (stalked or
pedicellate flower).
Some flowers may be
without stalk (sessile
flower).
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14. RECEPTACLE
✓The part of a flower stalk
where the parts of the flower
are attached.
✓A typical angiospermicflower
consists of four whorls of
floral appendages attached on
the receptacle
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15. PEDUNCLE
The stalk of a flower
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16. Hypogyny
❑When the thalamus is convex or
elongated, the carpel occupies the
top most position on it.
❑The other floral members (sepals,
petals, and stamens) are placed
below them. This mode of
arrangement is called hypogyny.
❑The flower is described as
hypogynous. The ovary is known as
superior. Insertion of Floral Leaves
on the Thalamus
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17. Perigyny
➢In this condition, the receptacle is flat or
slightly cup-shaped.
➢The carpels are situated at its centre and
other floral members are inserted on its
margin. This mode of arrangement is
called perigyny.
➢The flower is known as perigynous. In this
case, the ovary is still described as half
inferior.
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18. Epigyny
•When the thalamus is cup shaped, the lower
part of the ovary is situated at the bottom of
the cup and also fused with the inner wall of
thalamus.
•The other floral members appear to be
inserted upon the ovary. This mode on
arrangement is called epigyny. Then the
flower is said to be epigynous. the ovary is
said to be inferior
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20. PERIANTH, PETALOID &
SEPALOID PERIANTH
•In some flowers calyx
and corolla are
undifferentiated and
cannot be distinguished.
They are termed perianth.
•When the perianth is non-
green it is described as
petaloid.
•When the perianth is
green like the sepals, it is
described as sepaloid
perianth.
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21. TYPES OF FLOWERS
have either male or female parts but
not both & one or more sets of floral
structures are missing,
Complete Flowers
Incomplete Flowers
have both male and female parts
& all four floral structures.
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22. CLASSIFICATION OF FLOWER
•Essential parts of a
flower
•Non-essential parts of a
flower
Essential
(reproductive)
parts of a flower
are those that
are directly
associated with
reproduction.
E.g., Stamen and
Carpel (or
Pistil).
Non-essential
(accessory) parts are
those which either
protect the
reproductive parts of
the flower or make
the flower attractive
for pollination. E.g.,
Sepals and Petals.
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23. CLASSIFICATION OF FLOWER
•Monoecious
•Dioecious
The male and female
flowers are borne on the
same plant,for example,
gourd, maize, cucumber.
If either of the essential
whorls (i.e., androecium or
gynoecium)is lacking, the
flower is said to be unisexual.
•Unisexual
The male and female flowers
are borne on separate
plants, for example,
mulberry, palm, papaya.
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24. NEUTER
•Neuter –When
both, the staminate
and pistillate whorls
are lacking, the
flower is called
neuter, for example,
ray floret of
sunflower.
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25. If the staminate
whorl (androecium)
is absent or non-
functional, the flower
is said to be pistillate
-Incomplete flower
Staminate The non-
functional stamens –In this
type of flower, the pistil or
carpel (gynoecium) is either
totally lacking or non-
functional.
The non-functional
gynoecium is known
as pistillode.
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26. Thus the bundle
of anthers
arising from a
single part
(monadelphous)
The bundles
from two parts
(diadelphous)
From several parts
(polyadelphous)
The stamens are fused by their
filaments only. The anthers are
free. Fusion of filaments may
produce a single group
(monadelphous, e.g., chinarose),
two groups (diadelphous, e.g.,
pea) or many groups
(polyadelphous, e.g., citrus).
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27. Insertion and Adhesion of Stamens
Fixation of Anthers
Basifixed –
Filament attached
to the base of the
anther.
Dorsifixed -
Filament attached to
the dorsal (back)
side of the anther.
Adnate -Filament
attached along
the entire length
of anther.
Versatile –Filament
attached to a point on the
back or base of anther so
as to let it swing freely.
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28. •Distractile–When two
anther lobes are far
apart.
Divergent –When two
anther lobes separate due
to enlarged connective.
Types of Androecium According to
the length of the filament :
According to the number of
stamens :
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29. POLLINATION
❖POLLINATIONis the act of
transferring pollen grains from
the male anther of a flower to
the female stigma.
❖The goal of every living
organism, including plants, is to
create offspring for the next
generation.
❖One of the ways that plants
can produce offspring is by
making seeds.
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30. Cont.,
✓Pollination takes place by Bees, Birds,
Wind, Animal, Humans
✓Self-Pollination
✓Cross Pollination
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31. MARGINAL
•The placenta forms a
ridge along the ventral
suture of the ovary and
the ovules are borne on
this ridge forming two
rows.
•e.g., pea
AXILE
TYPES OF PLACENTA
The ovules develop on the inner wall of
the ovary or on peripheral part.
The arrangement of ovules within the
ovary is known as placentation.
•When the placenta is axial and
the ovules are attached to it in
a multilocular ovary.
•e.g., chinarose, tomato and
lemon.
PARIETAL
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32. Basal –the placenta
develops at the base of
ovary and a single ovule is
attached to it. e.g.,
sunflower, marigold.
Apical –the placenta
develops at the topof
ovary and a single
ovule is attached to it.
e.g., Mango
Free Central –When the ovules
are borne on central axis and
septa are absent. e.g.,
Dianthus, Primrose.
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33. •Ovules turn into seeds in
the mature fruit
(transformed ovary).
their different
arrangements can be
seen in fruits such as
those of pea, tomato,
mango, lotus, etc.
The mature ovary is a fruit,
and the mature ovule is a seed.
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34. Inflorescence
❖Inflorescence is the mode
of arrangement of flowers
on the axis of the plant.
❖Types of Inflorescence :
The flowers may be
arranged in several
different ways in different
plants -Single, Spike,
Racene, Corymb, Umbel,
Cyme, Panicle, Spadix,
Composite
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35. TYPES OF Inflorescence
•Spike-an elongate, unbranched,
indeterminate inflorescence with
sessile flowers.
•Spikelet-a small spike,
characteristic of grasses and
sedges.
•Raceme-an elongate,
unbranched, indeterminate
inflorescence with pedicelled
flowers.
•Panicle-a branched raceme.
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Corymb-a flat-topped raceme
with elongate pedicels reaching
the same level.
Compound Corymb-a branched
corymb.

37. •Umbel-a flat-topped or rounded inflorescence with
the pedicels originating from a common point.
Umbels can be determinate or indeterminate.
•Compound Umbel-a branched umbel, with primary
rays arising from a common point, and secondary
umbels arising from the tip of the primary rays.
•Capitulum (or head)-a dense vertically
compressed inflorescence with sessile flowers on a
receptacle and subtended by an involucre of
phyllaries, characteristic of the Asteraceae. Heads
can be determinate or indeterminate.
•Thyrse-a many-flowered inflorescence with an
indeterminate central axis and many opposite,
lateral dichasia
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38. USES OF FLOWERS
✓Flowers are not just beautiful to look at, but they also serve
a vital role in our ecosystem.
✓Flowers help our ecosystem flourish and attract a
plethora of lifeto the area and facilitate the expansion of
our environment. If flowers are cut down or destroyed
before pollination can occur, that particular species has a
high chance of dying off in that area. In addition, local wildlife
will also vanish in that area since they would have no food.
✓Flowers help keep the ecosystem growing and provide
new plant life, as well as help sustain local insects and
birds.
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39. CONTD.,
•It helps in the sexual reproduction of
the plant by producing male gametes
(pollen grains) and the female
gametes (egg cell).
•It helps in the process of pollination,
i.e., transference of pollen grain
from the anthers to the stigma of the
same or of the different flower.
•It help in the development of seeds
and fruits.
•It also helps in the dispersal of seeds
and fruits.
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40. REFERENCES
“SCIENCE READER”
➢Tamil Nadu text books
➢NCERT Books
➢Google Images
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