Tax 2 Essential Parts

Fayoum university Faculty of science Botany department

PLANT TAXONOMY For 2nd year students

Prepared by: Asmaa Khamiss

Revised by: Dr. Hesham Elfayoumi

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Essential floral parts- 4 A) Androecium) .It is the male sex organ* ).It consists of one or more stamen )s* Each stamen Consists of Anther

Consists of 2 lobes )theca) each one . contains pollen .grains )male ).gametes

Connective

Filament

Is a patch of tissues joins the anther lobes and connects between anther and filament

Carries the anther

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Stamens may be know as .Didynamous: 2 long+2 short stamens*

.Tetradynamous: 2 short+4 long stamens*

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

.Epipetalous: Attached with the petals*

Epipetalous staminal tube: Filaments are united to form this* .tube with free anthers, always, this tube is epipetalous e.g.: Malvaceae

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Free anthers

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Monadelphous: Numerous stamens in one bundle, may form* .one staminal tube

Diadelphous: Stamens in 2 bundles; A)9)+1* e.g.: Papilionaceae

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

.Polydelphous: More than 2 bundles*

Syngenesious: United anthers and free filaments. .

*

e.g.: Compositae disc floret

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

B) Gynoecium) .It is the female sex organ* ).It consists of one or more carpel )s* Each carpel (pistil) Consists of

Ovary

Style

Stigma

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Stigma .Is the terminal part of the gynoecium which recieves the pollen grains :Style Is the more or less elongated part of the gynoecium between the ovary and the :stigma , it may be

:Ovary Encloses one or more ovule )s), which after fertilization becomes seed and the Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi .ovary wall become fruit

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Carpels may be ) :United )Syncarpous*

) :Free )Apocarpous*

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Position of the ovary on the receptacle in relation to :the other floral parts

Epigenous

Hypogenous

Level of the ovary is below the level of the other floral parts on the rece.ptacle which in turn covers the ovary .and fuses with it

Level of the ovary is higher than the level of the other floral parts on the receptacle .

Perigenous Both the ovary and the other floral parts are at the same level on the receptacle

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Placentation It is the arrangement of the ovules inside the ovary, where the ovules are attached to the ovary wall in place known as . placenta

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Forms of placentation :Marginal* Placenta arises from the margin of the ovary wall at the # .conjunction of the two margins of the carpel .there is one carpel, one locule # e.g.: Leguminales #

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Parietal* Placentae bearing the ovules on the inner wall of the ovary and# .their position corresponds to the fusion of the carpel margins .Number of placentae = number of carpels # ).There are many carpels )=2 or more # e.g.: Cruciferae #

L.S

T.S

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Axile* Ovules arranged on a central axis arises from the base to the tip # .of the ovary wall .There are many carpels, many locules# (e.g. : Malvaceae, Solanum lycopersicum (Solanaceae #

T.S

L.S

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Free central* .Similar to the axile placentation but the tip of the axis is free # .The ovules arise on this axis without any septae # .There are many carpels, one locule # (e.g. : Capsicum annum (Solanaceae #

T.S

L.S

L . S & T. S

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Basal* Similar to the free central placentation, but with one ovule arises # .at the base of ovary and fills the ovary cavity .There is one carpel )rarely two), one locule # e.g.: Graminae #

L. S

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Apical* .As the reverse as the basal type # .There is one carpel )may two), one locule#

.L. S

: .e.g.: Umbelliferae

Apical axile* L. S #

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

How can you formulate a floral formula from a dissected ?flower

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Floral formula It is the number and figure of the flower contents represented by different symbols , these symbols refer :to A) Symmetry) :Which may be [Actinomorphic [Regular flower .When all the flower parts in each whorle are simillar in shape*

The flower can be divided into two equal halves along more than* .one median longitudinal plane

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

[ %Zygomorphic [Irregular .When the floral parts are unequal in shape* The flower can be divided longitudinally into two equal halves in* .only one vertical plane

Sometimes, the flower can not be divided into two equal halves, in this case the flower is Asymmetric. e.g.: Canna

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

B) Sexuality) :Flower may be Unisexual Male or Female [Bisexual [Hermaphrodite .Both male and female organs are present C) Perianth) :If we have a dicot flower, perianth may be Differentiated into Calyx )United k)x Free

kx

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Corolla )United C)x Free CX Un-differentiated into calyx & corolla sepaloid or petaloid) and called) Perianth )United P)x Free Px If we have a monocot flower, perianth is undifferentiated into caly & corolla Reduced or petaloid) and called) Tepals United T)x) Free Tx .Where the letter x refers to number of the floral units

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

D) Androecium) :May be )United A)x Free Ax Stamens may attach with the base of the petals and called epipetalous C A E) Gynoecium) May be with .United G)X) . Free Gx

in advanced flowers in primitive flowers

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

According to position of ovary )Superior ovary )Hypogenous flower* G ) Inferior ovary )Epigenous flower* G )Semi-inferior )Perigenous [indefinite[ flower* G F) Placentation) Should be written at the end of the floral .formula

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Summery If dicots K Or P or

C Or

A or G or both♀

Placentation%

♂

or

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

If monocots T or both or

A or or

G

Placentation%

♀

or ♂

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

How can you draw a floral diagram )T.S.) from a floral formula of a ?dissected flower

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Floral diagram Represents the cross section through the- 1 . flower It shows the arrangement of the floral - 2 .parts in relation to each other The rule is: the sepals, petals and- 3 .stamens are alternate to each other It is derived from the dissected flower,- 4 where we draw it from out side to inside .starting with the side, which near the stem From outside to inside = from up to down) ).ward = from posterior to anterior side

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:If we have this floral formula

K2+2

C4

A2+4

G)2)

Parietal

:We can draw the floral diagram as the following Calyx Corolla Placentation Stamens

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

.:From the previous floral diagram we can draw this L. S Complete sepal receptacl

Complete sepal Placentation

Where L. S. planned from the floral diagram in downward* .direction .It is drawn from left to right* It shows the arrangement of the floral parts longitudinally on the* .receptacle from left to right hand side During the planning of the L. S. we must take this rule in our* :consideration Length of: union of two epicalyx units < complete epicalyx unit < union of two sepals < complete sepal < union of two petals < .complete petal

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

:Another example K5

C5

A5

G)2)

Axile

. T. S.

L. S )Stem )main axis Complete sepal Stamen Placentation Complete petal

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi

Bract

:Third example K)5)

C5

A)00)

G)5)

Axile

Attachment of the staminal tube with the petals

Staminal tube

Epicalyx

Note: Epicalyx can be drawn in T. S. & L. S. but can not Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi .be written in the floral formula

Differences between monocot & dicot flowers

Monocot flowers

Dicot flowers

Perianth undifferentiated into- 1 calyx & corolla ; it’s units are .called tepals

Perianth differentiated into- 1 calyx & corolla ; some- times one [ .of them [sepaloid or petaloid The whorls are penta-- 2 .The whorls are tri-merous-2 merous ,sometimes are tetra).merous )Cruciferae In the floral diagram the stem- 3 In the floral diagram the stem- 3 is in the front of complete sepal is in the front of two free tepals or [except in order .union of two tepals Leguminales] the stem is in the front of two free sepals or union .of two sepals

Taxonomy of the flowering plants- Asmaa Khamiss&Hesham Elfayoumi