Plant SYSTEMATICS ,
Parts of Flower ,esssential and non essential part of flower ,calyx ,corolla ,Androecium, gynoecium ,Polyseplaous ,gamosepalous ,perianth
The flower is highly specialized reproductive shoot .
Each typical flower consist of four distinct types of memebers arranged in the form of whorls (circles) ,one above the other ,on the receptacle or Thalamus ,which is the enlarged end of the stalk called Pedicel.
he lower two whorls are called Accessory or Non essential and consist of generally small and green floral leaves ,the Sepals
and usually large ,coloured and attractive floral leaves ,the petals .
The whorl of sepals is called Calyx wherease the whorls of Petals is termed as corolla .
The upper two whorl are called Reproductive or Essential and consist of two kind of Sporophylls.
The microsporophylls or Stamens, forming the whorl androecium .
Each stamen consist of three parts --- Filament ,Anther & Connective .
The filament is the stalk of the stamen , and anther is the expanded head present at the tip of the filament.
Each anther is a bilobed ,the lobes are connected with one another by connectives .
The anther bear four chambers or Pollen Sacs , filled with Pollen grains or Microspores .
The Megasporophylls or Carpels forms the whorl gynoecium .
The carpel consist of three parts ---Ovary ,Style , & Stigma.
The ovary is the basal swollen portion of the carpel. It forms one or more chambers and contain one or more lottle rounded or oval bodies ,the ovules.
Each ovule encloses, an oval cell the embro sac .
On maturation ,the ovary give rise to fruit and the ovules to seeds.
The style is the stalk ike structure at the tip of which stigma is present .
The calyx and corolla are collectively known as Perianth .
Usually the sepals are differennciated from petals in size and colour but in some cases such as Lily and Tulips .,the seplas are large and colored as petals .
In certain other cases both sepals and petals are small and green .
When the perianth is green like sepals , it is called Sepaloid ,and when colored like Petals it is called Petaloid .
If the leaves of perianth are free from one another , the perianth is known as Polyphyllous , and if leaves are united ,it is said to be Gamophyllous .
bract is a special leaf ,which bears a flower or a cluster of flower in its axils . According to the form ,colour , and arrangements , the bracts may be classified as
Involucre ---- a group of bracts forming a cup - like structure , e.g in Sunflower
Glumes ----Small ,dry bracts enclosing flower ,as found in wheat .
pathe ------Large enclosing a cluster of flower e.g Date , Palm
Petaloid-----Petals like e.g Euphorbia ,Bougainvillea .
These are small leaves or scale-like structure present on the pedicle of flower .
They occur in pairs in dicots and singly in monocots , generally .
Sometimes ,the barcteoles form a whorl just below the calyx known as Epicalyx ,as in cotton (Gossypium herbaceum ). ets Malvaceae
2. The Flower
• The flower is highly specialized
reproductive shoot .
• Each typical flower consist of
four distinct types of memebers
arranged in the form of whorls
(circles) ,one above the other
,on the receptacle or Thalamus
,which is the enlarged end of the
stalk called Pedicel.
3. Essential and Non Essential Parts :
• The lower two whorls are called Accessory or Non essential and
consist of generally small and green floral leaves ,the Sepals
• and usually large ,coloured and attractive floral leaves ,the petals .
• The whorl of sepals is called Calyx wherease the whorls of Petals is
termed as corolla .
• The upper two whorl are called Reproductive or Essential and consist
of two kind of Sporophylls.
• The microsporophylls or Stamens, forming the whorl androecium .
• Each stamen consist of three parts --- Filament ,Anther & Connective .
4. Stamen :
• The filament is the stalk of the
stamen , and anther is the
expanded head present at the
tip of the filament.
• Each anther is a bilobed ,the
lobes are connected with one
another by connectives .
• The anther bear four chambers
or Pollen Sacs , filled with Pollen
grains or Microspores .
5. Carpel :
• The Megasporophylls or Carpels forms the
whorl gynoecium .
• The carpel consist of three parts ---Ovary ,Style ,
& Stigma.
• The ovary is the basal swollen portion of the
carpel. It forms one or more chambers and
contain one or more lottle rounded or oval
bodies ,the ovules.
• Each ovule encloses, an oval cell the embro sac .
On maturation ,the ovary give rise to fruit and the
ovules to seeds.
• The style is the stalk ike structure at the tip of
which stigma is present .
6. Perianth :
• The calyx and corolla are collectively known
as Perianth .
• Usually the sepals are differennciated from
petals in size and colour but in some cases
such as Lily and Tulips .,the seplas are large
and colored as petals .
• In certain other cases both sepals and petals
are small and green .
• When the perianth is green like sepals , it is
called Sepaloid ,and when colored like Petals
it is called Petaloid .
• If the leaves of perianth are free from one
another , the perianth is known as
Polyphyllous , and if leaves are united ,it is
said to be Gamophyllous .
7. A bract is a special leaf ,which bears a flower or a cluster of flower in its axils .
According to the form ,colour , and arrangements , the bracts may be classified as
Involucre ---- a group of
bracts forming a cup - like
structure , e.g in Sunflower
Glumes ----Small ,dry bracts
enclosing flower ,as found in wheat
.
8. Bracts :
Spathe ------Large enclosing a
cluster of flower e.g Date , Palm
..
Petaloid-----Petals like e.g Euphorbia
,Bougainvillea
9. Scaly and Leafy bracts :
Sclay Bracts ---smalla nd thin Leafy Bracts -- green and Leaf like
10. Bractioles :
• These are small leaves or scale-like
structure present on the pedicle of
flower .
• They occur in pairs in dicots and singly
in monocots , generally .
• Sometimes ,the barcteoles form a
whorl just below the calyx known as
Epicalyx ,as in cotton (Gossypium
herbaceum ). ets Malvaceae , (bhindi
family) .
• When the bracteoles are present ,the
flower is termed as Bracteolate.
