flowering plants morphology flower : whorls,symmetry,aestivation,placentation Leaf : parts,venation,types,phyllotaxy,modifications.

1. MORPHOLOGY OF FLOWERING
PLANTS

2. Parts of a flowering plant

4. Inflorescence
• The arrangement of flowers on a floral axis
• Depending on whether the apex gets
converted into a flower or continues to grow:
Recemose
Cymose

5. Recemose inflorescence
• the main axis continues to
grow
• The flowers are borne laterally
in an acropetal
succession
• Some times in centripetal
succession
• Eg : Crotalaria

6. Crotalaria Dahlia

9. Cymose inflorescence
• the main axis terminates in a
flower, hence is limited in growth.
• The flowers are borne in a
basipetal order
• Some times in centrifugal
succession
• Eg : Jasmine

11. FLOWER
• The reproductive unit in the angiosperm
• A typical flower has four whorls :
 Calyx
Corolla
Androecium
 Gynoecium
• If the calyx and corolla are not distinguishable –
Perianth (lilly, coconut)

12. Calyx and corolla – Accessory organs
Androecium and gynoecium- Reproductive
organs

13. Unit of each whorl
• Calyx – Sepal
• Corolla –Petal
• Androecium – Stamen
• Gynoecium – Carpel / Pistil

14. When a flower has
both androecium and
gynoecium
– Bisexual flower
When a flower has
either androecium
or gynoecium
– Unisexual flower

15. In Symmetry…
• Actinomorphic (Radial symmetry)
• - When a flower can be divided into
two equal radial halves in any radial plane
passing through the centre
• Zygomorphic ( Bilateral symmetry)
-When it can be divided into two
similar halves only in one particular vertical
plane

17. A flower may be trimerous,tetramerous or
pentamerous when the floral appendages
are in multiple of 3, 4 or 5, respectively

18. Based on the position of floral parts on
thalamus…
Flowers are of three types
• Hypogynous flower
•Perigynous flower
•Epigynous flower

19. Hypogynous flower
• Superior ovary
• other parts are situated below to ovary
• Mustard,China rose,brinjal

20. Perigynous flower
• Half inferior/ Half superiour ovary
• Other parts are situated on he rim of thalamus
,almost the same level
• Rose,peach

21. Epigynous fower
• Inferior ovary
• Other parts of flower arise above the ovary
• Guava,cucumber

22. Parts of a flower
Calyx
• Outermost whorl
• Unit- Sepals
• Sepals are green, leaf like and protect
the flower in the bud stage
• Gamosepalous- sepals united
• Polysepalous- sepals free

23. Corolla
• Composed of petals
• Petals usually bright coloured
• Pollination
• Gamopetalous – petals fused
• Polypetalous – petals free

24. Is rose coloured part corolla????

25. Aestivation
• The arrangement of sepals or petals in the
floral bud
• Valvate
• Twisted
• Imbricate
• Vexillary

27. Valvate
• sepals or petals in a whorl just touch
• one another at the margin, without
overlapping ( calotropis)

28. Twisted
• one margin of the appendage overlaps that of
the next one

29. Imbricate
• the margins of sepals or petals overlap one
another but not in any particular direction
• as in Cassia

30. Vexillary
• there are five petals
• the largest (standard) overlaps the two lateral
petals (wings) which in turn overlap the two
smallest anterior petals (keel)

31. 3. Androecium
• Male reproductive organ
• Composed of stamens
• Stamen : anther+ Filament
• Anther : Bilobed,each lobe has two chambers
– pollen sacs 9where the pollengrains are
produced)
• Filament : stalk of the stamen
• A sterile stamen is called Staminode

32. • Epipetalous
• Epiphyllous
• Polyandrous- stamens are free
• May be united
• monoadelphous
• diadelphous
• Polyadelphous

33. 4. Gynoecium
• female reproductive part of the flower
• Made up of one or more carpels.
• A carpel consists of three parts : stigma, style and
ovary
• Ovary is the enlarged basal part, on which lies the
elongated tube, the style.
• The style connects the ovary to the stigma.
• The stigma is usually at the tip of the style and is
the receptive surface for pollen grains

35. Overy
• When more than one carpel is present,
Apocarpous (carpels free )
Syncarpous ( carpels fused )

36. After fertilisation, the ovules develop into
seeds and the ovary matures into a fruit.

37. Placentation
• The arrangement of ovules within the ovary.
• marginal
• axile
• parietal
• basal
• free central

38. Marginal
• Ovary in which the placenta forms a ridge
along the ventral suture and the ovules are
borne on this ridge forming two rows
• Eg. Pea

39. Axile
• placenta is axial
• ovules are attached to placenta in a
multilocular ovary
• China rose, Lemon, Tomato

40. Parietal
• the ovules develop on the inner wall of the
ovary or on peripheral part
• Ovary is one-chambered but it becomes two
chambered due to the formation of the false
septum
• Mustard, Argemone

41. Free central
• ovules are borne on central axis
• septa are absent
• Dianthus, Primrose

43. Basal
• the placenta develops at the base of ovary
• a single ovule is attached to it
• in sunflower, marigold.

46. LEAF
• Lateral appendages of stem developing from
the nodes.
• generally flattened structure
• Leaves originate from shoot apical meristems
and are arranged in an acropetal order
• They are the most important vegetative
organs for photosynthesis.

47. • A typical leaf consists of three main parts:
Leaf base
Petiole
Lamina

48. Leaf base
• The leaf is attached to the stem by the leaf
base.
• It may bear two lateral small leaf like structures
called stipules
• In monocotyledons, the leaf base expands into a
sheath covering the stem partially or wholly.
Eg: Paddy

49. • In some leguminous plants the leaf base may
become swollen, which is called the pulvinus

50. Petiole
• The petiole help hold the blade to light
• Long thin flexible petioles allow leaf blades to
flutter in wind, thereby cooling the leaf and
bringing fresh air to leaf surface
• If petiole is absent - Sessile

51. Lamina
• The lamina or the leaf blade is the green
expanded part of the leaf
• veins and veinlets are seen here
• The main vein is called midrib
• upper side of leaf – Adaxial/ ventral side
• Lower side of leaf – Abaxial/ dorsal side
• The tip of leaf – leaf apex
• The edge of lamina – leaf margin

52. • Leaf shape, margin, apex, surface may be of
various shapes

54. Venation
• The arrangement of veins and the veinlets in
the lamina of leaf
• There are two types of venation :
Reticulate venation
Parallel venation

55. Reticulate venation
• When the veinlets form a network, the
venation is termed as reticulate
• Dicot leaf

56. Parallel venation
• When the veins run parallel to each other
within a lamina, the venation is termed as
parallel
• Monocot leaf

57. Types
• Leaves are mainly of two types
Simple
Compound
• Simple leaf : A leaf is said to be simple, when
its lamina is entire or when incised, the
incisions do not touch the midrib

58. Compoud leaf
• When the incisions of the lamina reach up to
the midrib breaking it into a number of leaflets,
the leaf is called compound
• The main petiole is called Rachis
• A bud is present in the axil of petiole in both
simple and compound leaves, but not in the axil
of leaflets of the compound leaf.

59. • The compound leaves may be of two types
• pinnately compound leaf : a number of
leaflets are present on the rachis, as in neem.
• palmately compound leaves: the leaflets are
attached at a common point, i.e., at the tip of
petiole, as in silk cotton.

60. Phyllotaxy
• Phyllotaxy is the pattern of arrangement of
leaves on the stem or branch
• This is usually of three types –
Alternate
Opposite
Whorled

61. Alternate type :
• a single leaf arises at each node in alternate
manner
• china rose, mustard and sun flower plants

62. Opposite type :
• A pair of leaves arise at each node and lie
opposite to each other
• Calotropis, guava plants

63. Whorled type :
• If more than two leaves arise at a node and
form a whorl, it is called whorled
• Alstonia, Allamanda

64. Leaf Modificaton
• The normal functions of leaf are
Photosynthesis,respirattion and transpiration
• Often leaves are modified to perform functions
other than the normal function
• These modification are called Leaf modification
 Leaf tendrils
 Leaf spine
 Leaf scale
 Phyllode
 Pitcher
 Bladder

65. Leaf tendrils
• They are converted into tendrils for climbing
• Pea plant

66. Leaf spine
• Modified into a sharp pointed structure
• for defence
• Cacti ( Opentia)

67. Leaf scale
• Modified into a thin membraneous structure
• In onion and garlic,the scale leaves are fleshy
due to storage of food materials

68. Leaf of acacia??

69. Phyllode
• In some plants such as Australian acacia, the
leaves are small and short-lived.
• The petioles in these plants expand, become
green and synthesise food.

70. Pitcher
• Modified to capture insects
• Nepenthes, venus flytrap

71. Bladder
• To capture small insects
• Utricularia

72. • The presence of more than one type of leaves on
a same plant - Heterophylly

73. • In nepenthes, the pitcher is modified
a. Leaf tip b. Stem c. leaf lamina d. lower part of petiole
• The leaves without petiole is
a.Sessile b. petiolate c.rachis d.stipule
• Phyllotaxy refers to the arrangement of
a.Leaves on a branch b. veins in a leaf
c.flowers on a branch d.axillary buds in a plant
• Phyllode is a modification of
a. Rachis b.stem c. lamina d. stipule
• In acacia the leaves are
a. Bipinnate b.unipinnate c.tripinnate
• Leaves are the common means of vegetative propagation in ………….
a. mango b.oxalis c. Bryophyllum d. Chrysanthemum