This document provides information on the parts and structure of flowers. It discusses the four main parts of flowers - calyx, corolla, androecium, and gynoecium. It describes the calyx (sepals) and corolla (petals) in more detail, including their arrangements, forms, and functions. It also covers concepts such as aestivation, which is the arrangement of petals and sepals as the flower develops.
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Floral parts
1. R. NITHYA M. Sc., M. Phil., (Ph. D)
ASSISTANT PROFESSOR IN
BIOTECHNOLOGY
SRI ADI CHUNCAHNAGIRI WOMEN’S
COLLEGE, CUMBUM, THENI DT
2. FLOWER
Flower is the reproductive part of Angiosperms.
It is a modified vegetative shoot.
Flower consist four parts
- Calyx
- Corolla
- Androecium
-Gynoecium
3. PARTS OF FLOWER
The flower consists two parts
Non Essential parts
- Calyx
- Corolla
Essential parts
- Androecium
- Gynoecium
Non Essential
Parts
Essential Parts
4. ARRANGEMENT OF FLORAL PARTS
A flower consist of a very shot axis, called thalamus.
Flower has four floral whorls arranged on the thalamus
- Outermost whorl - Calyx (Sepal)
- Outer whorl - Corolla (Petal)
- Inner whorl - Androecium (Male)
- Innermost whorl - Gynoecium (female)
Base of the flower called receptacle
5. PERIANTH
The non-essential parts of the flower are together called perianth.
The units of perianth is called tepal
Tepals free – polyphyllous
Tepals united - gamophyllous
6. CALYX
- Outermost whorl
- Formed of sepal
Sepals are free - polysepalous
Sepals are united - gamosepalous
7. SEPALS
In some plants, the sepals
are brightly coloured and petaloid.
Leaf like sepals- whitish or
yellowish
13. ACCRESCENT – PHYSALIS
The calyx is not only
persistent, but forms an
loose envelope around
the fruit.
14. FUNCTIONS OF CALYX
Gives protection to essential organs
Involved in photosynthesis
Calyx attracts insects for pollination
Calyx is modified into pappus hairs,
they persist on the fruit and help in
dispersal of seeds
15. COROLLA (PETALS)
- Second whorl of flower
- Formed of petals
- Delicate, thin and brightly coloured
- Flower without petals - apetalous
- Petals are free - polypetalous
- United petals - gamopetaous
FORMS OF COROLLA
Two forms - regular corolla
- irregular corolla
19. POLYPETALOUS AND IRREGULAR COROLLA
PAPILIONACEOUS COROLLA
The corolla consists five free and
unequal petals
One posterior standard petal or vexillum
Two lateral petals - alae or wing petals
Twoanterior petals - carinae or keel petals
E.g. Fabaceae or Papilionaceae
20. GAMOPETALOUS AND REGULAR COROLLA
Tubular corolla
The petals are united to form
a tube like structure.
E.g. Disc florets of Helianthus
23. ROTATE OR WHEEL SHAPED
Corolla is wheel shaped with
short corolla tube.
24. HYPOCRATE FORM OR SALVER SHAPED
The corolla has a narrow tube
and the limbs are attached
at right angle.
E.g. Vinca
25. GAMOPETALOUS AND IRREGULAR COROLLA
LIGULATE
The corolla has a short corolla tube and bears tongue shaped lobes
e.g. ray florets of Helianthus
26. BILABIATE OR TWO LIPPED COROLLA
The corolla has two projecting lips,
the upper lip is formed by two petals and
the lower lip is formed by the fusion
of 3 petals
E. g. Leucas, Ocimum
The throat of the corolla is always open
27. PERSONATE
The corolla is having two lips, but the lips are so close to one another
that the throat of the corolla remains always closed.
33. QUINCUNTIAL IMBRICATE
The margins of two sepals – towards inward
The margins of other two petals – outward
The remaining one petal one margin is towards
innerside other margin is towards the outside
34. VEXILLARY
The imbricate aestivation of papilionaceous
corolla is termed as vexillary aestivation.
There are two types of imbricate aestivation
Ascendingly imbricate
Decendingly imbricate
35. ASCENDINGLY IMBRICATE
The closure of the margins are from
Anterior side(lower side) to the
posterior side of (upper side)
the flower.
DECENDINGLY IMBRICATE
Margin of standard petal – Towards outside
Margin of two keel petals- Towards innerside
One margin of wing petals is Towards outside
One margin of wing petals is Towards innerside
37. INDUPLICATE CONVOLUTE
The petals have thick and thin portions.
The thin portions are folded inwards
and the corolla is twisted.
The thickened portions are exposed.