3. THE INFLORESCENCE
• Flowers may be produced singly or in groups
• Single- Solitary flower
• Group- Inflorescence
• In inf. definite pattern on reproductive branch
called peduncle
• A natural group of flowers produced on a
peduncle is called inflorenscence
4. Significance of Inflorescence
• Makes flowers conspicuous & attractive,
effective for pollination
• Inflorescence occurs successively and not
simultaneous, flowering periods is longer
• Criteria for identification & classification of
flowering plants
5.
6. Types of Inflorescence
• Racemose Inflorescence
• Also known as Indefinite inf because Peducle
shows indefinite growth period because it has
active terminal bud that is never converted
into terminal flower
• Flowers are borne laterally in acropetal
succession. The older flowers are at base and
the younger flowers are at top
7. • Order of flowers is Centripetal
• Old open first and low
• Young are in centre and mature later
8. Cymose
• Definte – peduncle has definite growth
• Because apical bud is converted to flower
• Arranged in Basipetal- first formed & old is
terminal
• Later or young- lower
• Order of flower opening – centrifugal
• E.g. Jasmine, Clerodendron
11. Parts of flower
• A flower like vegetative shoot may develop in the
axil of small leaf called bract, such flower is called
Bracteate flower
• Without Bracteate- Ebracteate flower, it is
produced on stalk called pedicel. The flower with
the stalk is called pedicellate or stalked flower
• Flower without stalk- non pedicellate or sessile
12.
13.
14.
15.
16. Parts of flower
• The terminal end is swollen and represents
floral axis, called Thalamus
• From each node of thalamus, a whorl of
leaves is produced
• Flower has 4 circles of modified leaves called
flora whorls
• Calyx, Corolla, Androecium, Gynoecium
25. Symmetry
• actinomorphic (radial symmetry) – When a
flower can be divided into two equal radial halves
in any radial plane passing through the centre.
e.g., mustard, datura, chilli.
• zygomorphic (bilateral symmetry) – When a
flower can be divided into two similar halves only
in one particular vertical plane. e.g., pea,
gulmohur, bean, Cassia.
• asymmetric (irregular) – if a flower cannot be
divided into two similar halves by any vertical
plane passing through the centre. e.g., canna
26.
27.
28. Insertion of flower leaves
– Hypogynous – the gynoecium occupies the highest position
while the other parts are situated below it. The ovary in such
flowers is said to be superior. e.g., mustard, china rose and
brinjal.
– Perigynous – If gynoecium is situated in the centre and other
parts of the flower are located on the rim of the thalamus
almost at the same level, it is called perigynous. The ovary here
is said to be half inferior. e.g., plum, rose, peach
– Epigynous – the margin of thalamus grows upward enclosing
the ovary completely and getting fused with it, the other parts
of flower arise above the ovary. Hence, the ovary is said to be
inferior. e.g., guava and cucumber, and the ray florets of
sunflower
30. Calyx (Sepals)
• Outermost whorl of the flower
• Generally, sepals are green, leaf like and
protect the flower in the bud stage
• The calyx may be gamosepalous (sepals united
e.g. China rose) or polysepalous (sepals free
e.g. Brassia)
31.
32.
33. Calyx
• When sepal fall off as flower bud open-
Caducous e.g. Argimone (poppy)
• Calyx survive till withering of petals- Decidous
e.g. Lotus, mustard
• Sepal remain even after fruit is formed-
Persistent e.g. brinjal, pea
34. Functions of Calyx
• Protect the essential whorl from injury
• Photosynthesis
• Attract insects for pollination
• Some are hairy- Pappus
• Such pappus is persistent helps in dispersal of
fruits
35. Corolla (petal)
• Second whorl larger than which is larger in
size, inner to calyx
• Colored & Scented
• Free from one another- Polypetalous (rose)
• United – Gamopetalous (datura)
36. Functions of Corolla
• Attraction, scented- pollination
• Gamopetalous- lower portion store nectar for
attraction
• In bud condition, petals protect the inner
organs, stamens & carpels
37. Perianth
• Calyx Corolla Morphologically similar-
together –Parianth and individual members-
Tepals
39. Functions of Perianth
• Functions as both calyx & corolla
• Protects the flower bud
• Petaloid helps in attraction
• Sepaloid helps in photosynthesis
40. Aestivation
The mode of arrangement of sepals or petals in floral
bud
• Types of aestivation:
1.Valvate: Sepals or petals do not overlap the sepal or
petal at margins. Ex.Calotropis
2. Twisted: Sepals or petals overlap the next sepal or
petal. Ex. Hibiscus, Cotton, China rose
43. Aestivation
3. Imbricate: The margins of sepals or petals
overlap one another but not in any definite
direction. E.g. Cassia, Bauhinia
4. Vexillary: The largest petal (standard/
vexillum) overlaps the two lateral petals
(wings) which in turn overlap two smallest
anterior petals (Keel). E.g. Pea Bean
44.
45. Androecium
• Male reproductive part- one or more stamen
• Free from each other- polyandrous
• United- epipetalous eg. Datura
• 3 Parts
• 1. Filament
• 2. Anther
• 3. Connective
46.
47. Filament
• Stalk of stamen that bears anther at the tip for
better dispersal of pollen grain
• Stamen are united by their filaments and
anther are free- Adelphy
• Monoandelpous e.g. Hibuscus
• Diadelphous e.g. Pea
• Polydelphous e.g. Lemon
48.
49. Anther
• Upper swollen fertile part of stamen usually 2
lobes
• Each lobes has 2 chambers called pollen
sacs/microsporangia within which pollen
grains/microspores are produced
• 2lobe- Dithecous anther, 1lobe- Monothecous
• When anther are united and filaments are
free- Syngeny eg. Sunflower
50.
51.
52. Connective
• It is the continuation with the filament
• It is a midrib-like, sterile structure between
the 2 fertile lobes of the anther connecting
them together- lenthwise
53. Gynoecium
• Female reproductive part (pistal)
• Innermost & 4th whorl, made up of one or
more carpels
• Female reproductive leaf called
Megasporophyll which produces megaspores
61. Ovary
• Each chamber of ovary contains one to many,
small, globular structures called ovules or
megasporangia
• Ovary are produced on a soft fertile tissue
called placenta
• They exibit different modes of arrangement
within ovary
62. Style, Stigma
• Style is narrow, elongated, thread like
structure that connects ovary with stigma
• Stigma is the terminal part of the carpel,
which receive pollen grains during pollination.
It also provides place for pollen germination.
• Stigma is generally rough and sticky in nature
