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

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Flower• Typical flower

– 4 main parts– Sterile whorls– Calyx&corolla– Fertile whorls– Androecium&Gynoeciu

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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 Variation

imperfect

perfect

imperfect

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

Pollen Dispersal by AnimalsBees, Beetles, Bats, Birds, Butterflies, etc…

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


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


Terms Applied to IndividualFlowers

• Staminate (=male):unisexual flowerwith just stamenspresent

Imperfect staminate flower; stamens only, no carples

• Carpellate(=female): unisexualflower just carpelspresent


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


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

Androecium:

tetradynamous didynamous

antisepalous(alternipetalous)

diplostemonous

antipetalous(alternisepalous)

obdiplostemonous

uniseriate biseriate

inserted exserted

Androecial / Stamen Fusion

apostemonous epipetalous


diadelphous monadelphous


syngenesious

basifixed subbasifixeddorsifixed dorsifixe

d basifixedversatil

e

longitudinal transverseporicidal valvular

extrorse latrorseintrorse

could also be upward

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)

Gynoecial Development/Fusion:

Gynoecial Fusion:

Crassula argentea Crassulaceae

Gynoecial Fusion:

Gynoecial Fusion:

Erythrina caffra Fabaceae

unicarpellous

Placentation

Borago officinalisBoraginaceae

Verbena rigidaVerbenaceae

Fragaria sp.Rosaceae

Morphology of flower

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