The document discusses flowers and their morphology. It defines flowers and their essential parts including the calyx, corolla, androecium, and gynoecium. It describes how flowers can be classified based on their arrangement of floral parts, number of whorls, symmetry, presence of sexual organs, and more. The summary provides high-level information about the topic and structure of the document in 3 sentences: The document defines flowers and their morphology, discussing their essential parts and how they can be classified based on characteristics like arrangement of parts, number of whorls, and presence of sexual organs. It provides details on the calyx, corolla, androecium, gynoecium

1. The Flower

2. Definition:
- It is morphologically compressed fertile shoot
with modified leaves or floral leaves.
- adapted for the production of fruits and seeds
(propagation of the plant).
- It is very important for the identification of
unknown plants.
INTRODUCTION

3. L.S in a typical flower

4. receptaclepedicel
L.S in a typical flower

5. The Floral Parts
Non-Essential parts Essential parts
Calyx Corolla Androecium
Gynoecium
Unit sepal Unit petal
Unit stamen Unit carpel
1 2 3
4

6. Typical flower “Complete flower”
Consists of:
1- Calyx: composed of sepals.
2- Corolla: composed of petals.
3- Androecium: composed of stamens.
4- Gynaecium: composed of carpels.
Incomplete flower
• When some floral parts as sepals or petals are
absent.

7. Side view Top view

8. Bracts & Bracteoles
Bract Bracteoles
accessory leafy structures
from its axils arises a flower
scale like leaves
accompanying the flower
present presentabsent absent
Bracteate flower
Ebracteate flower
Bracteolate flower
Ebracteolate f

9. Involucre: when bracts or bracteoles are present in
crowded form in one or more whorls.
Kinds of Flowers
Flowers are classified according to:
1-The arrangement of the floral leaves on the
flower axis.
2-The number of whorls present.
3-The number of segments in different whorls.
4-The presence of all floral parts.
5-The symmetry of all floral leaves.
6-The presence or absence of sexual organs.

10. • 1- The arrangement of the floral leaves
on the flower axis.
• 1.A- Cyclic flowers:
• The floral leaves of each whorl alternate
with those of the next.

11. • 1.B- Acyclic flowers:
• The floral leaves are spirally arranged

12. • 1.C- Hemicyclic flowers:
• The perianth is spirally arranged while the
stamens and carpels are in whorls.
• The calyx only is arranged in spiral
manner while the rest floral parts in
whorls.

13. 2-According to number of whorls present
• Tetracyclic: four whorls
• Pentacyclic: five whorls
3- According to the segments in different
whorls
• Isomerous: number of segments in different
whorls is usually the same
• Heteromerous: number of segments in different
whorls is unequal

14. 4- According to the presence of all floral
parts:
• Complete: The flower has all the usual parts.
• Incomplete: The flower is lacking one or some
of the regular parts.
5- According to the presence or absence
of sexual organs:
• a- Hermaphrodite: when both the male and
female organs are present.
• b-Sterile: when both male and female organs
are absent or not functioning.

15. c- Unisexual (imperfect):
• only one of the sexual organs is present
and functioning
i) Staminate: only male organ is present
ii) Pistillate: only female organ is present

16. 6- According to the symmetry of all
floral leaves:
• a- Regular or actinomorphic:
• The segments in each whorl are all alike
• The flower can be divided by a number of radial
longitudinal cuts into equal halves.

18. • b- Irregular
• one or more whorls are not alike.
• 1- Asymmetric:
• all the segments of the flowers are irregularly
arranged and not alike.
• Cannot be divided into equal parts.

19. • 2- Zygomorphic (%)
• When the flower can be divided only in
one plane into equal halves.

20. Parts of the flower

21. -Always very short but occasionally it is elongated
axis of the flower.
-Swollen or expanded apex of the flower stalk.
- It bears the floral parts.
1-Receptacle

22. - It consists of the non-essential parts of the
flower.
-When non-essential parts are not differentiated
into calyx and corolla, it is described as:
Petaloid: if brightly coloured
Sepaloid: thin, membranous and greenish
Polyphyllous: free segments
Gamophyllous: united segments
Achlamydeous (naked): outer part is absent
Perianth

23. - The outermost whorl of the floral series.
- Formed of sepals.
- Arranged in single whorl
- Colour: green but in some cases brightly coloured when petals are
absent to attract insect.
- Size: large sometimes very small, reduced to membranous or
represented by hairs.
-Function: protects the essential organs especially in the bud stage.
Calyx

24. Polysepalous Calyx
(free sepals inserted on the receptacle)

25. Gamosepalous Calyx
(united sepals)

26. - Second whorl after the calyx.
- Consists of petals mostly arranged in a single whorl.
- Size: larger than sepals.
- Function: Attract pollen grain carrying insects.
Corolla

27. - Colour: usually brightly coloured, this colour
may be due to the following pigments.
- Anthocyanins (red, blue and violet depending
on the pH of the cell sap).
- Flavone derivatives (yellow colour).
- Pigments such as carotin, xanthophyll (yellow,
orange and red colours).
- The white colour is due to the reflection of
light from the intercellular spaces of the
mesophyll but not to pigments.

28. Insertion of the floral parts on
the receptacle
PerigynousHypogynous Epigynous

29. Polypetalous corolla
(free petals)

30. Gamopetalous corolla
(united petals)

31. - It is the male sexual organ.
- One, two or more whorls of
stamens, sometimes
numerous.
- The stamens are situated
within or above the corolla
3-Androecium
Anther
Filament
Stamen
Pollen grains

32. Androecium
1-Types of
Androecium
2-Cohesion
of stamens
3- Insertion &
adhesion of stamens
on the floral parts
4- Attachment
of the anther
to the filament
Points to be studied concerning the androecium

33. Types of Androecium
1- According to the length of the filament
Didynamous
(two long and two short
stamens)
Tetradynamous
(four long and two short
stamens)

34. 2- According to the Number of stamens
Definite
(few stamens)
Indefinite
(numerous stamens)
Monandrous: (one stamen)
Diandrous: (two stamens)
Tri-, Tetra-,………
Polyandrous
(with indefinite number
of stamens)

35. Cohesion of stamens
• The union of stamens together
Monadelphous: filaments are fused in one group
Diadelphous: filaments are fused in two groups
Tridelphous: filaments are fused in three groups
Tetra-, Polydelphous: filaments are fused in several
groups
Syngenesious: filaments are free but anthers are
united

36. Insertion & Adhesion of stamens
• Adhesion may occur between stamens and various
floral parts.
- between stamens and petals Epipetalous
- between stamens and sepals Episepalous
- between stamens and gynoecium Gynandrous
- Anthers are adherent to stigma Gynostegium

37. Attachment of the anther to the
filament

38. - Fine powder liberated on the dehiscence of the
anthers.
- Minute with different shapes and sizes but they
are constant for each species.
- Its wall is of two layers Exine and Intine
- Exine may be smooth and cutinized while the
Intine is delicate, cellulosic and rich in pectic
substances.
- They are the most characteristic elements found
in powdered flowers.
Pollen grains

40. Exine have:
i) Germ pores: one, two or more, through one
of which the pollen tube protrude.
ii) Germinal furrows: grooves to
accommodate the expansion and shrinkage of
the pollen due to change in humidity

41. Gynoecium
Carpel
(pistil)
-It is the female sexual organ.
-Consists of one or more carpels.
-Described as : mono-carpellary
bi-carpellary
or poly-carpellary

42. Types of Gynoecium
I- Apocarpous II- Syncarpous
(The carpels are free) (The carpels are
united together)

43. Typical carpel

44. Description of the different parts of
a carpel
• 1- Ovary:
- may be simple formed of a single carpel.
- or compound formed of more than one
carpel.
- The compound ovary may be formed of two,
three or more compartments
bi-, tri- or multi-locular ovary
- The walls separating the compartments are
called septum.

45. Insertion of the ovary
Inferior ovary
(when the floral parts
appear inserted on the
top of the ovary)
Superior ovary
(when the floral parts are
inserted on the receptacle
below or on the same level
as the ovary)

46. Placentation
• It is the position or arrangement of placenta in
the ovary.
• The ovules are normally arranged on double
parallel cords

47. Placentation

48. 2- Style and stigma
Stigma with or without style is inserted on the apex of
the ovary.
Style may be long or short or totally wanting.
Style may be united with stamens Gynostemium
Stigma may be united with anthers Gynostegium
If the style is present, the stigma is called stalked
while if absent it is called sessile.

49. • The stigma surface may be papillose surface
on which the pollen can germinate.

50. Inflorescence
• Definition:
It is the aggregation of the flowers on the
plant.
• Kinds of inflorescence:
(According to the mode of branching)
I- Racemose inflorescence.
II- Cymose inflorescence.
III- Mixed inflorescence.

51. Inflorescence
- Indefinite.
- Monopodial branching.
- Youngest flower at the
apex or at the centre.
- Oldest flowers at the
base or to the outside.
1- Racemose Inflorescence 2- Cymose Inflorescence
- Definite.
- Sympodial branching.
- Youngest flower near
the base or to the
outside.

52. 1- Racemose
Inflorescence
2- Cymose
Inflorescence

53. Capitulum
(= flower head)
• It is a racemose inflorescence having very short
swollen flattened axis and on which are inserted
sessile flowers.
• It is encircled by involucre consisting of bracts,
the flowers are generally small and called florets.
1- Racemose Inflorescence

54. • There are two types of florets inserted on the
same capitulum:
• The central which have tubular corolla and
called tubular or disc florets.
• The marginal which have strap-like corolla and
called ligulate or ray florets.

55. III- Mixed Inflorescence
When both racemose
and cymose types of
branching occur on the
same inflorescence.