Morphology of flower
-
Upload
khangminh22 -
Category
Documents
-
view
0 -
download
0
Transcript of Morphology of flower
• Floral characteristicsare the mostcommonly usedfeatures to identifyplants
Flowers• Floral characteristics
are the mostcommonly usedfeatures to identifyplants
Flower• A typical flower is a
stem tip bearing twowhorls ofappendages, twoare sterile and twoare fertile
• All four whorls areconsidered to bemodified leaves
• A typical flower is astem tip bearing twowhorls ofappendages, twoare sterile and twoare fertile
• All four whorls areconsidered to bemodified leaves
• Typical flower– 4 main parts– Sterile whorls– Calyx&corolla– Fertile whorls– Androecium&Gynoeciu
m
Flower• Typical flower
– 4 main parts– Sterile whorls– Calyx&corolla– Fertile whorls– Androecium&Gynoeciu
m
Flower Anatomy
Calyx: the outer whorl of sepals;typically these are green, but arepetal-like in some species.
Calyx: the outer whorl of sepals;typically these are green, but arepetal-like in some species.
Flower Anatomy
Corolla: the whorl ofpetals, which areusually thin, soft andcolored to attractanimals that help theprocess of pollination.
Corolla: the whorl ofpetals, which areusually thin, soft andcolored to attractanimals that help theprocess of pollination.
Flower Anatomy
Androecium (from Greekandros oikia: man'shouse): one or morestamens, each with afilament topped by ananther where pollen isproduced.
Pollen contains the malegametes.
Androecium (from Greekandros oikia: man'shouse): one or morestamens, each with afilament topped by ananther where pollen isproduced.
Pollen contains the malegametes.
Flower AnatomyGynoecium (from Greek gynaikos oikia:woman's house): all the female parts—thepistil(s) with ovule(s) inside.
Flower AnatomyThe basic unit of the female reproductivestructure is the carpel. Each physcial bodyis called a pistil.
A flower may have a single carpel, which isa simple pistil (unicarpellate), or severalcarpels united in one compound pistil(syncarpous), or a cluster of un-unitedcarpels/pistils (apocarpous)
The sticky tip of the pistil, the stigma, is thereceptor of pollen.
The supportive stalk, the style, becomesthe pathway for pollen tubes to grow frompollen grains adhering to the stigma, to theovules, containing the gametes, housedinside the ovary.
The basic unit of the female reproductivestructure is the carpel. Each physcial bodyis called a pistil.
A flower may have a single carpel, which isa simple pistil (unicarpellate), or severalcarpels united in one compound pistil(syncarpous), or a cluster of un-unitedcarpels/pistils (apocarpous)
The sticky tip of the pistil, the stigma, is thereceptor of pollen.
The supportive stalk, the style, becomesthe pathway for pollen tubes to grow frompollen grains adhering to the stigma, to theovules, containing the gametes, housedinside the ovary.
Flower Structure VariationA flower having sepals, petals, stamens, andpistils is complete; if a flower is lacking one ormore of these whorls, it is said to beincomplete.
no stamens present = incompleteincomplete
complete
• The position of thegynoecium inrelation to all theother floral parts isthe basis for theterminology usedin keys andtaxonomicdescriptions
Insertion of Floral Parts• The position of the
gynoecium inrelation to all theother floral parts isthe basis for theterminology usedin keys andtaxonomicdescriptions
• Hypogynous: thesepals, petals, andstamens areinserted under thecarpel– Ovary is said to be
superior
Insertion of Floral Parts• Hypogynous: the
sepals, petals, andstamens areinserted under thecarpel– Ovary is said to be
superior
• In a perigynousflower, the sepal,petals, and stamensare fused togetherto form a cup calledthe hypanthium– The gynoecium sits
inside the cup but isnot fused to it
– Ovary is said to besuperior
Insertion of Floral Parts• In a perigynous
flower, the sepal,petals, and stamensare fused togetherto form a cup calledthe hypanthium– The gynoecium sits
inside the cup but isnot fused to it
– Ovary is said to besuperior
• In aepigynousflower,the sepals, petals,and stamens arisefrom a point abovethe ovary– Ovary is said to be
inferior
Insertion of Floral Parts• In a
epigynousflower,the sepals, petals,and stamens arisefrom a point abovethe ovary– Ovary is said to be
inferior
SymmetryFlowers that are actinomorphic have"radial symmetry", meaning they can bedivided into symmetrical halves by morethan one longitudinal plane passingthrough the axis.
Zygomorphic flowers are "yokeshaped” or have"bilateral” symmetry,where flowers can be divided by onlya single plane into two mirror-imagehalves.
• Perfect (=bisexual):flower with bothstamens andcarpels
Presence or Absence ofParts
Terms Applied to IndividualFlowers• Perfect (=bisexual):
flower with bothstamens andcarpels
Grape flower with stamens and carpels
Presence or Absence ofParts
Terms Applied to IndividualFlowers• Imperfect
(=unisexual):missing stamens orcarpels, but not both
• Imperfect(=unisexual):missing stamens orcarpels, but not both
• Staminate (=male):unisexual flowerwith just stamenspresent
Presence or Absence ofParts
Terms Applied to IndividualFlowers
• Staminate (=male):unisexual flowerwith just stamenspresent
Imperfect staminate flower; stamens only, no carples
• Carpellate(=female): unisexualflower just carpelspresent
Presence or Absence ofParts
Terms Applied to IndividualFlowers• Carpellate
(=female): unisexualflower just carpelspresent
Imperfect carpellate flower; carpel only; nostamens
• Monoecious: anyplant that has bothstaminate andcarpellate flowers
Presence or Absence of PartsTerms Applied to Plants with Imperfect
Flowers
• Monoecious: anyplant that has bothstaminate andcarpellate flowers
• Dioecious: plant thathas either staminateflowers or carpellateflowers, but not both
Presence or Absence ofParts
Terms Applied to Plants with ImperfectFlowers
• Dioecious: plant thathas either staminateflowers or carpellateflowers, but not both
• ★androecium• filament• anther
• Types• distinct stamen diadelphous ~• didynamous~ polyadelphous~• tetradynamous~ syngenesious~• monadelphous~
• ★androecium• filament• anther
• Types• distinct stamen diadelphous ~• didynamous~ polyadelphous~• tetradynamous~ syngenesious~• monadelphous~
Type ofStamen
1.Monadelphous stamen
2.Diadelphous stamen
3.Didynamous stamen
4.Tetradynamous stamen
5.Polyadelphous stamen
6.Syngenesious stamen
Type ofStamen
1.Monadelphous stamen
2.Diadelphous stamen
3.Didynamous stamen
4.Tetradynamous stamen
5.Polyadelphous stamen
6.Syngenesious stamen
Type of Stamen1.Didynamous stamen2.Polyadelphous stamen 3.Monadelphous
stamen 4.Synantherous stamen 5.Diadelphous stamen6.Tetradynamous stamen
antisepalous(alternipetalous)
diplostemonous
antipetalous(alternisepalous)
obdiplostemonous
uniseriate biseriate
Gynoecium= all female parts of a flower
Pistil= structure consisting of ovary, style(s), and
stigma(s)
Carpel= conduplicate megasporophyll
Carpel can be unit of pistil, if pistil compound(composed of >1 carpel)
Gynoecium= all female parts of a flower
Pistil= structure consisting of ovary, style(s), and
stigma(s)
Carpel= conduplicate megasporophyll
Carpel can be unit of pistil, if pistil compound(composed of >1 carpel)