how flower is a shoot modification

1. Submitted to- Deepika mam
Submitted by- arun saini
Class –b.sc medical
Roll no.-1369610054

2. The most widely accepted view about the
morphological nature of flower is that it is highly
condensed vegetative shoot of limited growth,
modified to perform reproductive function in
angiosperm. Lateral appendages
i.e. floral part of flower are equivalent to foliage leaves
Resemblance to floral bud
 Position- both vegetative and floral buds are terminal
or axillary in position
 Modification- floral buds are some time modified into
vegetative buds or bulbils in some plants e.g.-
pineapple

3. Axis nature of thalamus
The thalamus of flower is considered as a condensed axis
in which nodes and internodes are highly condensed so
that floral parts borne on nodes appear to arise at the same
level.
 Internode - well developed internodes are present
between calyx and corolla called Anthophore , between
corolla and androecia called Androphore,
between androcium and gynoecium called Gynophore
 Monstrous development – it is growth of thalamus
after development of floral parts to form foliage leaf e.g.
rose, pear

4. LEAFY NATURE OF FLORAL PARTS
 Phyllotaxy – the arrangment of floral
leaves on the thalamus resemble to that
of foliage leaves . E.g. lily ,cactus
 Aestivation – floral leaves exhibit the
aestivation similar to that of foliage
leaves.
 The stamen of some primitive flowers
are expanded like leaves.
 Like wise of carpels degeneria do not
bear distict style and stigma. They
appear like partially rolled up leaves

5. Function of floral parts
Function of calyx- the outer whorl of flower
consist of sepals which together constitute calyx.
 Calyx provide support and protection to the
thalamus and inner floral whorls
 Green calyx perform the fuction of photosynthesis
 When bright coloured , calyx aids in pollination.
 Modification of calyx in some perform special
fuction e.g. spinous in protection

6. Function of corolla- second inner whorl
of floral parts consist of petals which together
constitute corolla
 Corolla protects the inner essential whorl in bud
conditon and even after opening of flower
 Bright colour and presence of scent and nector
serecting gland attract pollinators
 Shape size and various other devices in corolla
regulate the entry of insect or bud pollinators

7. Function of androecium –
 third whorl of floral parts called stamens
together constitute androcium.
 Stamen are male sex organ in the flower
anther produce a large no. of pollen grain
 Whorls of anther also aids in dispersal of
pollen grain.

8. Function of gynoecium- forth of inner
most whorl of flower are the female sex organ and
consist of one or more carpels which together
constitute gynoecium.
 Stigma receive pollen grain and aids in their
germination
 Style carry the stigma high above in the flower to
increase its effectiveness of receiving pollen grains
 Seed remain protected inside
the ovary
 Seed provide nourishment and
protection to the embryo