STRUCTURE OF MATURE ANTHER

In a flower, stamen is considered as the male reproductive organ. Each stamen consists of filament, connective and anther. Anther may be monothecous or dithecous. A monothecous anther consists of two locules or two sporangia. So it is said to be bilocular or bisporangiate. A dithecous anther consists of four locules or four sporangia. So it is said to be tetralocular or tetrasporangiate.

Development of microsporangium is eusporangiate. A very young anther in transverse section shows epidermis and archesporium. The archesporial cells divide periclinally giving rise to primary parietal cells. On the outer side and sporogenous cells towards innerside. The cells of the parietal layer divide periclinally and anticlinally forms endothecium, middle layers and tapetum. The cells of the primary sporogenous tissue differentiated into pollen mother cells or microspore mother cells.

                                                 

The anther wall consists of following walls layers.

1.Epidermis: Epidermis is the outermost single layer. It  is compactly arranged and usually protective in function. Epidermal stomata was reported in Alangium.

2.Endothecium: The cells of the endothecium are radially elongated and shows fibrous bands. The fibrous bands are made up of callose an arise from the inner tangential walls. Usually fibrous bands are “U” shaped. Fibrous bands are absent in Hydrocharitaceae, Saprophytes and Cleistogamous flowers. Endothecial thickenings are also absent in Musa, Sesamum, Annona, Ipomea etc but in these members the anther epidermis has deposition of cutin and lignin. The fibrous bands are hygroscopic in nature. Endothecial cells help in the dehiscence of anther at maturity. Because of the presence of fibrous bands, this layer is otherwise called fibrous layer. It is single layered but in Coccinia double layered.

3.Middle layers: Below the endothecium 2-3 layers of cells are present which constitute middle layers. These layers are ephemeral and become crushed by early meiosis in pollen mother cells. These cells act as storage centres for starch.

4.Tapetum: Tapetum is the innermost layer of antherwalls, and it  completely surrounds the sporogenous tissue. The cells contain dense cytoplasm with prominent nuclei. Usually tapetum consists of single layer of cells. As the tapetum completely surrounds the sporogenous tissue major part of it is derived from parietal cells and a small part developed from the sporogenous tissue. Tapetum transports the nutrients to the developing sporocytes. Tapetal cells are pigmented and it is red brown in apple or violet in Anemone

  Base on the behaviour,  two kinds of tapetum were recognised.

a)    Amoeboid tapetum:

 The inner and radial walls of the tapetum break down due to the action of hydrolytic enzymes and their protoplast penetrates between the pollen mother cells and developing pollen grains. After intrusion, they fuse with each other and forms a mass of tapetal periplasmodium. This tapetal plasmodium remains associated with the pollengrains till their maturity. When the anther gets drying up the tapetal periplasmodium gets dehydrated and coated over the surface of pollengrains, thereby helping in the formation of exine. Amoeboid tapetum is considered as the primitive type. It is also called periplasmodial tapetum. Eg:- Alisma, Tradescantia, Typha, Saggitaria, Potamogeton.

b)   Glandular tapetum:

The cells of glandular tapetum remains intact throughout microspore development. They secrete their substances from their innerfaces. Secretary tapetal cells are thin and possess almost all cell organells like mitochondria, plastids, dictyosomes etc. some spherical structures called proubisch bodies are also present. Just before the pollen mother cells undergo meiosis, the walls of the tapetal cells become thick and there is considerable increase in the no. of ribosomes and pro-ubisch bodies with the completion of pollen development proubish bodies pass into the anther locule from the tapetal cells and they are now called ubisch bodies and they coated over the pollengrains Eg:- Higher monocots and many dicots.

Functions of tapetum:

1.   The nutrients are transported through tapetum to the sporogenous tissue.

2.   Tapetum is involved in the synthesis of callose which release microspores in a tetrad by degrading callose wall.

3.   Tapetum plays an important role in the formation of exine.

4.   Pollen kit (Lipids and carotenoids) is formed by tapetal layer. It is a insect attractant & protect pollen from ultra violet.

Technical description of Calotropis gigantea

1.    HABITAT: Mesophyte with xerophytic adaptation.

2.    HABIT    : Shrub.

3.    ROOT    : Not provided.

4.    STEM    : Herbaceous, aerial, erect, cylindrical, solid, glabrous with milky latex.

5.    LEAF     : Cauline (or) ramel, opposite decussate, subsessile, simple,exstipulate, ovate to eliptical, entire, acute, glaucus, reticulate unicostate, coriaceous.

6.    INFLORESCENCE         : Extra axillary, umbelate (or) dichasial cyme.

7. FLOWER IN GENERAL : Pedicellate, bracteate, ebracteolate (or) bracteolate, complete, bisexual, actinomorphic, cyclic, hypogynous, pentamerous, dichlamydeous and heterochlamydeous.

8.    FLOWER IN DETAIL  : 5 Sepals, polysepalous, asendingly imbricate, 5petals, polypetalous, valvate, 5 , epipetalous or gynandrous, exerted stamens, introrse,dithecous anther.

Basifixed in asclepiadoideae behind the stamens the extentions of coralla are present called coronary coralla.

The two anther lobes of adjacent stamens fuses to form a lambda shaped structure called translator mechanism.

Androecium fuses with gynoecium to from gynostegium.

Gynoecium : 2 carpels, bicarpellary, sub-apocarpous, bilocular, superior, marginal placentation, terminal, fuses with pentagonal disc.

TECHNICAL DESCRIPTION OF A FLOWERING PLANT

1. HABITAT: The surrounding environment of a plant

v  Mesophytes

v  Xerophytes

v  Hydrophytes

2. HABIT: Characteristic form or bodily appearance of an organism.

                   A) Herbs, Shrubs, Trees.

                        Herb  :  Small plants with soft stems are called herbs.

         Shrub:  Shrubs are mostly larger than herbs. They give rise to woody branches from the                        soil level   to  form bushy plants.

        Trees: Trees are large, woody with prominent main trunk, which normally give rise to many branches.

3. ROOT: Underground part of the plant body.

v  Tap root                 : A primary root developing from the radical of the embryo.

v  Adventitious root  : Root developing from any part of the plant body except the radical.

4. STEM: Aerial part of the plant body.

A) Texture:

v  Herbaceous: Non-woody.

v  Woody        : Hard in texture.

    B) Types of stems

   a) Aerial/Underground:

v  Aerial            : Remains above the ground in the air.

v  Underground: Remains below the ground.

                       b) Erect/weak:

v  Erect  : A rigid and strong stem growing upright in position.

v  Weak : Not strong enough to keep itself in a upright position. They are  three types

C)      Form :

v  Cylindrical: Circular in transverse section.

v  Angular     : Showing many angles (Tri, Quadra, Pent angular)

D)      Interior:

v  Solid    : A stem having filled interior.

v  Fistular : A stem having hollow interior.

E)      Surface:

v  Glabrous: Without hairs (or) smooth.

v  Hairy      : Covered with hairs.

v  Spiny      : Covered with prickly spines.

5. LEAF : Leaves are the lateral, exogenous appendages developed from the nodes of a shoot system.

A)      Insertion: Position of leaf in a plant body.

v  Radical: Leaves born on an underground reduced stem.

v  Cauline: Leaves born on the main stem.

v  Ramal : Leaves born on the lateral branches.

B)      Phyllotaxy: The mode of arrangement of leaves on the stem or branch is called “Phyllotaxy”.

1)       Alternate: Single leaf arising at each node and alternate with each other.

     2)  Opposite: Two leaves are present at a node opposite to one another.  It is of two types.

                  a) Opposite decussate   : A Pair of opposite leaves at successive nodes are present at  

                                                           right angles to each other.

                   b) Opposite superposed: A Pair of opposite leaves at successive nodes are arranged 

                                                            one above the other in the same plane.

     3)  Whorled      :  More than two leaves at each node as a whorl.

     4) Leaf mosaic: Older leaves present at the lower nodes of the stem possess longer petioles with          

                               bigger lamina and the young leaves of upper nodes bear shorter petioles with  

                                smaller lamina.

                                      

                               Alternate                              Opp. deccusate                          opp.superposed

Whorled                               

C)      Leaf attachment: Petiolate or Sessile.

1. Petiolate: Leaf base situated on the stalk or petiole.

v  Pulvinous: Swollen petiole base.

v  Sheathing : Leaf base is broad and surrounds stem

2. Sessile: Leaf without stalk or petiole.

D)      Type of leaf :

1.       Simple: The leaf having simple undivided lamina.Eg: Mango.

2.       Compound: The leaf lamina is completely divided into many segments called leaf lets or pinnas. It is of two types

a) Pinnately compound  : The leaf let’s develop on the lateral sides of the rachis.

v  Uni-pinnately compound: The leaflets directly born on the primary rachis.

Paripinnate     : With even pair of leaflets. Eg: Tamarindus.

Imparipinnate: With odd number of leaflets. Eg: Margosa.

                     

Paripinnate                                    Imparipinnate

v  Bi-pinnately compound: The primary rachis divided once and produce secondary rachii.  

                                                The leaflets develop on secondary rachii.Eg: Delonix.

v  Tri-pinnately compound: The rachis divides twice and produces secondary and tertiary  

                                                 rachii. The leaflets develop on the tertiary rachii. Eg:Moringa.

v  Decompound leaf          : Primary rachis divides many times without any definite order. 

                                                                The lamina is dissected into many units. Eg: Coriandrum.

                                 

Bi pinnately leaf              Tri pinnately compound                       Decompound

b) Palmately compound: Leaflets are arranged at the tip of the petiole.

v  Unifoliate  : With a single leaflet.   Eg: Citrus.

v  Bifoliate    : With two leaflets.        Eg:Hadwickia.

v  Trifoliate   : With three leaflets.      Eg:Oxalis.

v  Tetrafoliate: With four leaflets.       Eg:Marsilea.

v  Pentafoliate: With five leaflets.       Eg:Gynandropis.

v  Multifoliate : With many leaflets.    Eg: Ceiba.

                                      

Unifoliate                      Bifoliate                              Trifoliate

                                          

Tetrafoliate                   Pentafoliate                         Multifoliate

     E)   Stipules: Stipules are the small lateral appendages present on either side of the leaf base.

v  Stipulate    : Stipules are present on either side of leaf base.

v  Exstipulate: Stipules are absent

     F) Shapes of leaves:

        The shape of lamina is the description of its form. It has various shapes.

v  Acircular      : Needle shaped.  Eg: Pinus

v  Linear           : Long and slightly broader.  Eg: Grasses

v  Lanceolate    :  Shaped like lance. Eg: Nerium

v  Orbicular       :  More or less circular. Eg: Lotus

v  Elliptical       : Like an ellipse. Eg: Vinca

v  Ovate            : Egg shaped.  Eg: Hibiscus

v  Spathulate     : Spoon like. Eg: Euphorbia

v  Oblique     : Lamina with unequal halves. Eg: Margosa

v  Oblong       : More or less rectangular. Eg: Banana

v  Reniform   :  Kidney shaped. Eg:  Hydrocotyle

v  Cordate ­     : Heart shaped (with a deep notch  at the base). Eg: Betel vine

v  Saggitate    : Shaped like an arrow  head.  Eg: Saggitaria

v  Hastate       : Like saggitate but the two basal lobes are directed outwards. Eg: Ipomea

v  Lyrate         : Shaped like a lyre. Eg: Mustard

v  Centric        : Hollow and cylindrical. Eg: Onion

v  Cuneate       : Wedge shaped. Eg: Pistia

v  Obovate      : Oval but slightly broader at the apex than at the base Eg: Cassia

v  Deltoid       : Triangular/Delta shape. Eg: Abutilon

G) Margin of Leaf:

    The  margin of the lamina may be of different types

v  Entire    :  Smooth margin. Eg:  Mango

v  Repand : When the margin is wavy. Eg: Polyalthia

v  Serrate  : Saw like margin. Eg: Margosa

v  Spiny    :If the margin is spiny. Eg: Argemone

v  Crenate : Margin with rounded  teeth. Eg: Bryophyllum

v  Dentate : Large pointed teeth like margin. Eg: Water lily

H) Apex of Leaf:

     The apex of the leaf lamina shows variations in different plants

v  Acute               : When  the apex is narrow and pointed. Eg: Mango.

v  Acuminate       : If the apex is drawn out into a long tapering tail. Eg: Ficus religiosa.

v  Obtuse             : When the apex is  round. Eg: Banyan.

v  Mucronate       : Round apex  with sharp pointed tip. Eg: Vinca.

v  Cuspidate         : When the apex is spinous.  Eg: Date palm.

v  Tendrillar         : When the apex form a tendril. Eg: Gloriosa.

v  Cirrhose           : When the mucronate apex ends with fine thread like structures.eg: Banana.

v  Truncate           : If the apex is abruptly cut with across. Eg: Paris Polyphylla

v  Retuse              : If the obtuse apex slightly notched. Eg: Pistia.

v  Emarginated :If the obtuse apex is deeply notched. Eg: Bauhinia.

                                   

                      

I) Surface of Leaf:                                              

     The surface of the leaf lamina may be

v  Glabrous   : Smooth and with out  hairs. Eg: Mangifera

v  Glaucus      : Covered  by waxy coating  with white tinge. Eg: Calotropis

v  Scabrous  : Rough surface. Eg: Ficus

v  Viscose    : Sticky surface. Eg: Cleome

v  Pubescent : Covered with soft  and wooly hair. Eg: Tomato

v  Pilose       : Covered with long distinct scattered hairs. Eg: Grewia pilosa

v  Hispid      : Covered with long rigid hairs. Eg: Cucurbita

v  Spinous   : Covered with small spines. Eg: Solanum xanthocarpum

J) Venation:

     The arrangement of veins in the lamina of a leaf is called venation   In angiosperms there exists two types                          

     of   venation. They are

v  Reticulate:  vein lets are irregularly distributed forming a network.

v  Unicostate(Pinnate): Having single prominent mid rib. Eg:Mangifera.

v  Multicostate(Palmate) : Having more than one prominent veins arisig at the apex of petiole

a)       Convergent :Veins run from base to apex  in a curved manner Eg: Zizyphus.

b)       Divergent  :Prominent veins  arising from the tip of petiole diverges from one another                 towards margin of leaf Eg: Cucurbita.

                            

Simple                          Pinnate                                     Palmate

v  Parallel  : Veins run parallel to each other , network is not found

v  Unicostate (Pinnate)   : Having single prominent vein that gives off many lateral veins which          

                                              run   parallel towards margin Eg: Banana.

v  Multicostate (Palmate) : Having more than one prominent veins

                a) Convergent: Prominent veins arising from the base of a leaf blade run parallel  

                                        towards  apex   Eg: Grass

                b)Divergent: Prominent veins arising from the tip, of petiole diverge towards the  

                                     margin of leaf  blade in  more or less parallel manner .Eg: Borassus.

                     

Simple                          Pinnate                                     Palmate

K) Texture of Leaf:

      The texture of leaf lamina also varies in different species

v  Herbaceous  : When the lamina is thin and soft

v  Coriaceous   : When the lamina is leathery

v  Succulent     : When the lamina is thick ,soft and juicy

v  Hygrophytic : When the lamina is very thin , membranous and spongy

6. INFLORESCENCE: Specialized stalk bearing variable number of flowers is called inflorescence.

a) Position of Inflorescence:

v  Terminal: Developed from the apices of Main stem Eg: Crotalaria.

v  Axillary: Developed in the axils of leaf Eg: Hibiscus

v  Intercalary: Borne at internodes Eg:Callistemon

v  Cauliflory: Flowers are formed directly on old stems. Eg: Polyalthia

        b) Type of inflorescence:

   1) Racemose inflorescence: Indefnite growth of peduncle and flowers are arranged acropetally

v  Simple raceme: Simple unbranched peduncle produce many pedicellate , bracteate flowers in acropetal manner. Eg: Crotalaria.

v  Compound raceme or Panicle: Peduncle is branched, each branch is a simple raceme Eg: Mangifera.

                           

v  Simple Corymb: All the flowers on a peduncle are arranged in acropetal manner and are brought more or  less to the same height. Eg: Cassia.

v  Compound Corymb: Peduncle is branched, each branch is a simple corymb.Eg: Cauliflower.

                    

v  Simple Umbel: Many pedicellate flowers arise from the apex of the peduncle. Eg:Allium.

v  Compound Umbel: Peduncle is branched, each branch produces a simple umbel at its apex                             Eg: Coriandrum.

                   

v  Spike: A simple raceme with sessile flowers

Eg: Amaranthus.

v  Compound Spike: Compound spike has branched peduncle with each branch, a spikelet. The axis of the spikelet is called rachilla and form bottom sterile bracts called glumes, above them fertile bracts bearing flowers called lemma are present. The axis of flower bears reduced bracteoles called palea and essential organs are arranged above the reduced perianth lobes called lodicules. This inflorescence is a characteristic feature of the family Poaceae.

        

v  Catkin: A  spike inflorescence with weak ,drooping peduncle. Eg: Acalypha

v  Simple Spadix: A spike inflorescence with fleshy peduncle covered by a large spathe (a modification of bract) Eg: Colocasia.

v  Compound Spadix: Peduncle is branched covered by spathe Eg: Cocos.

                                                                                                                  

v  Head:  Peduncle is condensed into a flattened disc called receptacle. Flowers are arranged in centripetal manner

A)      Homogamous head :-  Inflorescence with only one type of florets i.,e ray (or)disc florets

B)      Heterogamous Head :- Inflorescence with disc and ray  florets.

                           

2)  Cymose:  Growth of the peduncle is condensed, with definite number of flowers

v  Solitary cyme: It is the simple cymose inflorescence. The axis bears only single flower at its apex.  

                                Eg: Hibiscus rosasinensis.

                   

v  Simple cyme or cymule : Inflorescence axis terminates into single flower which in turn bears  two

                                      lateral flowers. A three flowered  inflorescence is formed. Eg: Jasmine.

v  Monochasial cyme:   Inflorescence axis terminates into a flower and produce only  one  branch from    

                                 its bract 

                   a)Helicoids cyme:  Monochasial cyme in which the successive lateral branches develop only on  

                                                   one side in a spiral manner. Eg: Hamelia.

                b) Scorpoid cyme : Monochasial cyme in which the successive lateral branches develop in a zig   

                                              zag manner.  Eg: Heliotropium.

                                

v  Dichasial cyme :   In this  type after the peduncle terminates into a flower the inflorescence  axis  

                           produces two  lateral branches and this  type of branching continues so it is called   

                          dichasial  cyme. Eg: Clerodendron.

v  Polychasial cyme :  After the peduncle terminating into a flower, the inflorescence axis  produces               

                              many lateral branches , hence it  is called polychasial cyme. Eg: Nerium.

3) Special type of inflorescence:   Due to some modification in some inflorescence the opening and arrangement  

                                                      of flowers remains special

v  Verticillaster : This type of inflorescence consists of flowers arising  in the  axils of  leaves arranged  

                        oppositely  to each other. At every node  in the axil of leaves flowers develops                

                         initially into dichasial cyme and lateral into monochasial cyme.  The flowers  are   

                         sessile and  axes are so short that flowers are crowded round the node like a false whorl    

                         (Verticel) hence it is   called vertcillaster. Eg: Leucas

v  Cyathium   :  It is a single flower like inflorescence.  It is covered by a deep cup like involucres of   

                             bracts with external nectaries at the centre of this cup there is a  single female flower      

                             encircling this female flower many male flowers are arranged in scorpoid cyme. Eg:  

                             Euphorbia

v  Hypanthodium  : It is a fruit like inflorescence. The inflorescence axis is condensed and forms a

                                   fleshly, cup like structure with an apical opening. Eg: Ficus.

Ø  7. FLOWER IN GENERAL :

            A) Pedicel: Stalk of an individual flower.

v  Pedicellate: A flower having a pedicel.

v  Sessile: A flower without a pedicel.

    B) Bract: A modified leafy structure in the axis of which a flower arises.

v  Bracteate: Flowers having bracts.

v  Ebracteate: Flowers without bracts.

    C) Bracteole: A secondary bract at the base of an individual flower.

v  Bracteolate: The flowers having bracteoles.

v  Ebracteolate: The flowers without bracteoles. 

    D) Presence of Floral Whorls:

v  Complete: A flower having all the four whorls i.e., calyx, corolla, androecium, gynoecium.

v  Incomplete: A flower lacking one or more whorls.

    E)  Presence of Reproductive Organs:

v  Bisexual: A flower with both stamens and carpels.

v  Unisexual: A flower having only one sex organ i.e., either androecium (Staminate)or   

                                Gynoecium (Pistillate)

   F) Structural Symmetry:

v  Actinomorphic (regular): A flower with radial symmetry i.e., the parts of each whorl are  

                                                 similar    in size and shape; the flower can be divided into two  

                                                 equal halves along more than one median longitudinal plane.

v  Zygomorphic               : A flower with bilateral symmetry i.e., the parts of one or more              

                                                       whorls are dissimilar ; the flower can be divided into two equal   

                                                       halves in only one vertical plane. i.e., along the axis.

v  Asymmetric flower (irregular) : A flower which can not be cut into two equal halves in any  

                                                           Plane. Eg: Orchids

    G) Arrangement of Floral Organs:

v  Acyclic (spiral): The thalamus is conical or convex and the floral parts are arranged spirally.

v  Cyclic: The floral organs are arranged in definite whorls.

v  Hemi cyclic( Spiro cyclic):Sepals and petals are arranged in regular whorls and androecium 

                                                   and Gynoecium are arranged spirally

   H) Position of Floral Organs on Thalamus:

v  Hypogynous: A flower in which all the other organs i.e., calyx, corolla, androecium are  

                              situated below the level of ovary; ovary superior.

v  Perigynous: The floral organs viz, sepals, petals and stamens are born and arise from around  

                            the ovary and not beneath it; ovary half superior or inferior.

v  Epigynous: The floral organs viz, sepals, petals and stamens are attached to the upper part of    

                           the ovary; ovary is inferior.

   I) Merosity: Number of floral parts in each whorl

v  Dimerous    : Floral parts in 2’s or multiple of two.

v  Trimerous   : Floral parts in 3’s or multiple of three.

v  Tetramerous: Floral parts in 4’s or multiple of four.

v  Pentamerous: Floral parts in 5’s or multiple of five.

           J) Nature of Perianth:

v  A chlamydeous: Perianth is absent and flowers appeared naked Eg: Euphorbia

v  Chlamydeous: Perianth is present. These are of two types.

              a) Monochlamydeous: Flower with perianth in one whorl Eg: Amaranthus

              b) Dichlamydeous: Perianth is distinguished in to calyx and corolla.

v  Homochlamydeous: Calyx and corolla are similar in all respects (size and                     

                                       shape)

v  Heterochlamydeous: Calyx and corolla are dissimilar in all respects (size and          

                                           shape)

8. FLOWER IN DETAIL:

A) Calyx: The outer whorl of flower composed of the sepals.

            a) Number of Sepals: 3 or 4 or 5 or more

   b) Cohesion:

v  Polysepalous: Sepals are free and separate.

v  Gamosepalous: Sepals are fused in whorl or in part.

     c) Aestivation: Mode of arrangement of sepals/petals in the bud.

B) Corolla: The second whorl of flower composed of the petals.

            a) Number of Petals: 3 or 4 or 5 or more

   b) Cohesion:

v  Polypetalous: Petals are free and separate.

v  Gamopetalous: Petals are fused in whorl or in part.

   c) Aestivation: Mode of arrangement of sepals/petals in the bud.

v  Valvate: Sepals/petals are arranged closely with small gaps between them. Eg: Calyx of Hibiscus

v  Twisted: Sepals/petals overlap one another i.e., one margin of the sepal /petal is covered by the next one  Eg:  Corolla of Datura

v  Imbricate : Out of five sepal/ petals one is completely outside, one completely inside, and the  

                          remaining three with one margin inside and one margin outside.

v  Ascendilingly Imbricate: The odd petal is posterior and completely inside, one of the  

                                                 anterior petal is completely out side. The remaining 

                                                 petals show regular overlapping in ascending manner. Eg:  

                                                  Corolla of Caesalpinaceae

v  Descendingly Imbricate: The odd petal is posterior and completely outside. The anterior  

                                                Pair of petals are completely inside. The remaining  

                                                petals how regular overlapping in the descending manner. 

                                                 Eg: Corolla of Fabaceae

v  Quincuntial:  Out of five sepals/petals, two are completely outside, two are completely inside,

                             The remaining has one margin outside and one margin inside. Eg: Calyx of                

                             Ipomea

              

    C) Androecium:

v  It is the third whorl of the flower 

v  Individual units are called as stamens

v  Each stamen has a fertile anther and  filament

a)       Number of stamens:

b) Cohesion of stamens:  Union among the stamen

v  Monadelphous:  All filaments unite to form a single bundle.  Eg: Hibiscus

v  Diadelphous   : All filaments unite to form two bundles. Eg:  Tephrosia

v  Polyadelphous: Filaments unite to form many bundles.  Eg : Citrus

v  Syngenesious: Here the anthers of filaments are united and the filaments remain free.  

                                Eg: Tridax

v  Synandry: Here all the stamens of flower unite completely to form a single structure. 

                        Eg: Cucurbita

v  Polyandrous: Stamens are indefinite and free.

               c) Adhesion of Stamens:   Stamens may unite with other floral organs like sepals, petals or gynoecium.  

v  Epiphyllous:  Stamens unite with perianth. Eg: Asparagus

v  Episepalous: Stamens unite with sepals.

v  Epipetalous: Stamens unite with petals. Eg: Datura

v  Gynandrous: Stamens unite with gynoecium .It is also called gynandrium or

Gynostegium. Eg:  Calotropis.

             d) Insertion of Stamens:

v  Haplostemnous: Stamens in one whorl are usually as many as the number of sepals or  petals

v  Diplostemonous: Stamens in two alternating whorls, the members of outer whorl alternate with petal

v  Obdiplostemonous: Stamens in two alternating whorls, the members of outer whorl opposite the petals

v  Polystemnous:  Stamens in more than two whorls

           e) Length of the Stamens: Stamens in a flower are of the same length but in some cases it varies  

                                                      accordingly.

v  Didynamous: Androecium has six stamens in which two are long and other two  

                              are short.Eg: Ocimum.

v  Tetradynamous:  Androecium has 6 stamens arranged in two whorls. The outer 

                                   two stamens are short and inner four are longer. Eg: Brassica

TETRADYNAMOUS       DIDYNAMOUS

         

            f) Position of the Stamens:

v  Inserted stamens: in some flowers the filaments are shorter than the petals .so the stamens remain within the flower. Eg: Datura

v  Exerted stamens: In some flowers the filament of stamens are longer than the petals. Eg: Acacia Arabica

       g) Length of stamens:

v  Extrorse: When the ventral surface of anther faces the petal and the condition is called   

                     extrose

v  Introrse: When the ventral surface of anther faces the gynoecium called introse.

        h) Number of Anther Lobes:

v  Dithecous anther:  In this two anther lobe are present. Eg: Datura

v  Monothecous anther: In this only one anther lobe is present. Eg: Hibiscus

        i) Fixation of Anther: The filament is attached to anther in different ways

v  Basifixed: the filament is attached to the baser of the anther. Eg: Datura

v  Dorsifixed: the filament is attached to the anther on the mid dorsal side. Eg: Hibiscus

v  Adnate: the filament is attached to the whole length at the back of the anther.Eg: Nelumbo

v  Versatile:  the apex of the filament is pointed and is attached to the back of the anther at a point , so that the latter can swing freely in any direction. Eg: Oryza sativa.

  

         j) Dehiscence of Anther: At maturity the anther dehisces to liberate pollen grains.  

v  Longitudinal: the anther dehisces longitudinally. Eg: Datura

v  Transverse: the anther dehisces horizontally. Eg: Hibiscus

v  Valvular : the wall of the anther lobe dehisces like a valve. Eg: Cassytha

v  Porous: the anther lobes dehisce in the form of pores at their apices. Eg:  Solanum   

   D) Gynoecium:         

v  The innermost whorl of the flower

v  Individual unit are called as carpels

v  Each carpel has ovary, style and stigma

     a)Number of Carpels :

v  Monocarpellary: Gynoecium with one carpel.      Eg: Dolichos

v  Bicarpellary     :  Gynoecium with two carpels.    Eg: Solanum

v  Tricarpellary    :   Gynoecium with three carpels. Eg: Allium

v  Tetracarpellary:   Gynoecium with four carpels.   Eg: Oenothera

v  Pentacarpellary:  Gynoecium with five carpels.    Eg: Hibiscus

v  Multicarpellary:   Gynoecium with many carpels.Eg: Annona

    b) Fusion of Carpels:    The carpels of gynoecium may remain free or fused.

v  Apocarpous:  the carpels present on the thalamus remain free. Eg: Annona

v  Syncarpous: the Carpels of the ovary are completely or partially fused. Eg: Hibiscus

  c) Number of Locules :

v  Unilocular    :  With one locule.     Eg: Dolichos

v  Bilocular      :  With two locules.   Eg: Solanum

v  Trilocular     :  With three locules. Eg: Allium

v  Tetralocular:   With  four locules.  Eg: Ipomea

v  Pentalocular:  With five locules.    Eg: Hibiscus

v  Multilocular:  With  may locules.   Eg: Abutilon

  d) Position of the Ovary :

v  Superior :   It is seen in hypogynous flowers. The gynoecium is placed on the thalamus

v  Inferior:   It is seen in epigynous flowers.The thalamus is deep cup like structure  in which  

                      gynoecium is placed.

 

  e) Placentation:    The mode arrangement of ovules in the ovary is called placentation

v  Marginal placentation :  The ovary is unilocular. The ovules are borne on the ventral suture  

                                               of ovary. Eg: Dolichos

v  Parietal placentation : The ovules are borne on the inner walls of the ovary that bears  

                                           incomplete  partitions. Eg: Brassica

v  Axile placentation: The ovules are attached  to central axis present in the bi to multilocular  

                                       ovary. Eg: Hibiscus

v  Free central placentation: This placentation is developed from the axile placentation with

                                                 degradation of septa. Eg: Dianthus

v  Basal placentation:  This is found in unilocular ovary. The ovules are few or reduced to one  

                                         and are borne on the base of the ovary. Eg: Tridax

v  Superficial placentation: It is found in multilocular ovary. Ovules develop all round the inner

                                               surface of the septa. Eg: Nymphaea

f) Style:  It is a long stalk above the ovary 

v  Terminal:   It arises from the apical part of the ovary. Eg: Hibiscus

v  Lateral    :   Style arises from the lateral side of the ovary. Eg: Mangifera

v  Gynobasic:  Style arises from the base of the ovary in between the four locules. Eg: Ocimum

      g) Stigma:   It is the terminal end of the style which receives pollen grains

v  Capitate    :  Rounded stigma

v   Bifid        :  Forked

v   Feathery  :  Faethers

v   Discoid    :  Disc shaped

v   Dumbbell :  Dumbbell shaped

v  Linear       :  Long

v   Sticky      :  With  sticky fluid.