ISC-12>PRACTICAL>TAXONOMY

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Terminology useful for the practical-

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STUDY OF FLORAL CHARACTERISTICS THROUGH FLOWER DISSECTION

A. AIM: To study the floral characteristics of family Malvaceae by dissection of Hibiscus rosa-sinensis

• Division: Angiospermae
• Class: Dicotyledonae
• Family: Malvaceae
• Genus: Hibiscus
• Species: rosa-sinensis 

        (China rose, Shoe flower)

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• Inflorescence: Solitary axillary

• Floral characteristics: 

Pedicellate, complete, cyclic, bracteolate in the form of epicalyx, hermaphrodite, actinomorphic, hypogynous, regular and pentamerous.

• Epicalyx:
  

1. Number- 5-7
   
2. Colour – Green
   
3. An additional whorl below calyx
   

• Calyx:

1. Number- 5
2. Fusion- Gamosepalous
3. Aestivation- Valvate
4. Shape –bell shaped
5. Colour- Green

• Corolla:

1. Number- 5
2. Fusion- Polypetalous
3. Aestivation- Twisted
4. Shape –Bell shaped ,slightly fused due to fusion with staminal tube
5. Colour- red

• Androecium:  

Stamen

1. Number.-Indefinite
2. Cohesion- Monoadelphous. i.e forming a staminal tube around the style.
3. Adhesion -Epipetalous i.e. filaments adnate to the basal part of the petal.

 Anthers

1. Reniform, i.e. kidney shaped
2. Free and monothecous.
3. Basifixed, extrorse, 

• Gynoecium:
  

Carpel

1. Number of carpels-5, (Pentacarpellary)
   
2. Fusion - Syncarpous.
   

Ovary- Superior, pentalocular with 1 or 2 ovules in each locale
Style- Long, united below, free above, passes through staminal tube
Stigma-Five in number, capitate
Placentation-Axile

Characteristic of the family: 

• Presence of epicalyx
• Petals with twisted aestivation
• Stamens indefinite and monoadelphous
• Anthers reniform and monothecous
• Ovary two- many carpels with axile placentation.

Economically important plants:

Edible plants:

1. Hibiscus  esculantus (lady’s finger)
   
2. Bombax  ceiba ( silk cotton tree)
   

• Fiber yielding plant:
  

1. Gossypium spp. (common name: cotton)
   
2. Hibiscus cannabinus (common name: patsan)
   

• Cortical fibers used for cordage and ropes:
  

1. Hibiscus rosa-sinensis (shoe- flower)
   

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B. AIM: To study the floral characteristics of family Solanaceae by dissection of Datura stramonium

Classification

• Division- Angiospermae
• Class- Dicotyledonae
• Family- Solanaceae
• Genus- Datura 
• Species – stramonium
  

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• Inflorescence :Solitary axillary
  
• Flower: Ebracteate, Pedicellate,complete, bisexual/hermaphrodite, actinomorphic,  hypogynous, pentamerous, cyclic.

• Calyx:         

1.  Number-Five
2. Fusion- Gamosepalous
3. Aestivation-Valvate.
4. Duration: Persistent

• Corolla:

1. Number-Five
2. Fusion- Gamopetalous
3. Aestivation-twisted 
4. Shape-Infundibuliform/ funnel shaped/ bell shaped

• Androecium:

      Stamen

1. No of stamens -Five 
2. Cohesion: Polyandrous with long filaments.
3. Adhesion :Epipetalous

     Anthers

1. Connate/long
2. Basifixed
3. Dithecous 
4. Introrse

• Gynoecium

     Carpels

1. Bicarpellary
2. Syncarpous

Ovary :  Superior, carpels placed obliquely
Style:   Long
Stigma:  Slightly bilobed
Placentation :  Axile with swollen placenta/ obliquely placed placenta

 Characters of the family solanaceae

• Sepals and petals are fused
  
• Five stamens
• The flower is epipetalous
• In the ovary, carpels are placed obliquely.

  Economically important plants:

•   They provide several important food and medicinal plants.
  

1. Capsicum annum (chilles)
   
2. Solanum tuberosum (potato)
   
3. Lycopesicon  esculentum (tomato)
   

• Medicinal plants
  

1. Atropa belladonna 
2. Withania somnifera (ashvagandha)

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C. AIM: To study the floral characteristics of family Amaraylldaceae by dissection of Crinium lily.

Classification

• Division –Angiospermae
  
• Class – Monocotyledonae 
  
• Family- Amaraylldaceae
  
• Genus-Crinium 
  
• Species-lily
  

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• Inflorescence: Umbel
  
• Flower:   Bracteate, pedicellate, complete, actinomorphic, hermaphrodite, trimerous, epigynous.

• Perianth 

1. Number of tepals- 6
2. Arrangement:  arranged in two separate whorls of three part each(trimerous).
3. Fusion: Polyphyllous. 
4. Petalloid.
5. Aestivation: Twisted 

• Androecium

     Stamens

• Number-Six in two trimerous whorls 
• Fusion:-Polyandrous.
• epiphyllous(fused to tepals)

      Anthers

• Dorsifixed or pseudobasifixed.
• Dithecous.
• extrorse.

 Gynoecium:
      Carpel

• Number  of carpels- 3
• Fusion - Syncarpous.

     Ovary:

• Superior
• Trilocular

     Style:  Slender
     Stigma:  Minute
     Placentation:  Axile

Characters of the family 

• Inflorescence scapiferous umbel type
  
• Perianth petalloid
  
• Ovary inferior and trilocular with many ovules
  
• Stamens six into two trimerous whorls

Economically important plants:

• Edible plants: 
  

1. Allium cepa,
   
2.  Allium  sativum (garlic)
   

• Medicinal plants: 
  

1. Aloe vera: Constituent of laxative preparations.
   
2. Colchicum luteum: Useful in rheumatism and liver diseases.
   

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D. AIM: To study the floral characteristics of family Fabaceae/ Leguminosae by dissection of Clitoria ternate.

Classification 

• Division: Angiospermae
  
• Class: Dicotyledonae 
• Family: Fabaceae
• Genus: Clitoria 
  
• Species: ternate  ( Butterfly pea)
  

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• Inflorescence: Racemose type
• Flower -Complete, pedicellate, bracteate, hermaphrodite, zygomorphic, hypogynous, pentamerous, papilionaceous.

Calyx:

1. Number -5
   
2. Fusion:  gamosepalous
3. Aestivation :valvate
4. Odd sepals anterior

 Corolla:

1. Number- 5 
   
2. Fusion: polypetalous
   
3. Papilionaceous, i,e the posterior petal is largest called standard, two lateral petals are called wings and inner to anterior petals fused to form boat shaped structure called the keel.

Aestivation is vexillary
Androecium:
   Stamen 

• Number- 10
• Diadelphous (9+1)
• 9 fused stamens are placed anteriorly and one free is placed posteriorly.

   Anthers:

• Basifixed, 
• Dithecous
• Introrse

Gynoecium:
    Carpel

• Monocarpellary.
• Unilocular

   Ovary- Superior, unilocular
   Style- Long and curved
   Stigma- Flattened or feathery
  Placentation- Marginal

  Characters of family leguminosae

• Flower zygomorphic
  
• Corolla papilionaceous or butterfly shaped
  
• Ten stamens diadelphous 
  
• Marginal placentation
  
• Vexillary aestivation
  

Economically important plants:

• Edible plants-
  

1. Vigna  mungo (black gram), 
2. Vigna  radiata (green gram)
   

• Medicinal plants
  

1. Abrus  precatorius (rati), 
2. Glycyrrhiza  glabra (liquorice), 
   

• Ornamental plants
  

1. Clitoria  ternatea ( butterfly pea),
2. Lathyrus  odoratus ( sweet pea)

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E. AIM: To study the floral characteristics of Family Asteraceae/Compositae through dissection of flower Helianthus annuus.

Classification

• Division –Angiospermae
  
• Class – Dicotyledonae 
  
• Family- Asteraceae/Compositae
  
• Genus-Helianthus 
  
• Species-annuus

Inflorescence: Capitulum, with involucres. It consists of two types of flowers:
a) Ray florets (ligulate type) and
b) Disc florets tubular type.
Flowers:

RAY FLORETS
Position: Arranged on the periphery of capitulum
Flower (Floral characters):
Bracteate, sessile, incomplete, pentamerous, zygomorphic, ligulate, pistillate, irregular, epigynous.
Calyx: Absent or 3 and modified into pap pus.
Corolla: Petals 5, gamopetalous, having a short basal tube.
Androecium:Absent.
Gynoecium:
Carpel: absent or bicarpellary
Fusion: Syncarpous
Ovary: inferior, unilocular
Style: single
Stigma: Bifid and hairy
Placentation: Basal

DISC FLORETS
Position: Arranged in the central part of the capitulum.
Flower (Floral characters):
Bracteate, sessile, complete, tubular, actinomorphic, pentamerous bisexual and epigynous.
Calyx: Reduced and modified into 2-3 scales called pappus.
Corolla: Petals 5, gamopetalous and tubular, valvate aestivation.
Androecium: 
Stamens - 5, syngenesious, epipetalous,
Anthers - dithecous, bilobed, basifixed, introrse.
Gynoecium:
Carpels: 2 (bicarpellary)
Fusion: Syncarpous
Ovary: inferior, unilocular
Style: long
Stigma: Bifid
Placentation: Basal

Characteristics of the family:

• Inflorescence capitulum
  
• Calyx is pappus
  
• 5 syngenesious stamens
  
• Inferior ovary and basal placentation
  

Economically important plants: Provide food, dye, oil and medicines.
Calendula officinalis (medicinal), Marigold, Chrysanthemum

Edible plants:
Cichorium intybus (blended with coffee), Helianthus tuberosus

Oil yielding:
Carthamus tinctorius (safflower), Helianthus annuus (sun flower)

Ornamental:
Dahlia pinnata

OR

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Classification

• Division –Angiospermae
  
• Class – Dicotyledonae 
  
• Family- Asteraceae/Compositae
  
• Genus-Tridax
  
• Species-procumbens
  

AIM: To study the floral characteristics of family Asteraceae/Compositae. 

Inflorescence- Head or capitulum type of inflorescence.

TUBULAR OR DISC FLORETS

• Bracteate, ebracteolate, sessile, complete, bisexual, pentamerous, actinomorphic and epigynous.

Calyx

• Number: Numerous, Reduced into hairy outgrowths called pappus arranged on top of ovary and persistent.

Corolla

• Number- 5
  
• Fusion- gamopetalous 
  
• Regular, tubular 
  
• Aestivation- valvate 

Androecium
Stamens

• Number-5 
• Epipetalous, syngenesious and alternate with petals. 

Anthers

• Dithecous
• basifixed, 
• Introrse and dehiscing longitudinally.

Gynoecium
Carpel-Bicarpellary,  unilocular
Ovary Inferior, and syncarpous. 
Style-simple 
Stigma-bifid
Placentation-basal. 

LIGULATE OR RAY FLORETS 
Bracteate, ebracteolate, sessile, incomplete, pistillate, zygomorphic and epigynous.
Calyx

• Number- Numerous, reduced into hairy outgrowths called pappus arranged on top of the ovary and persistent.

Corolla

• Number- 5
  
• Fusion- gamopetalous, irregular, ligulate or bilabiate, the anterior lip is large and 3 lobed, the posterior one is small in the form of 2 teeth like projections 
  
• Aestivation - valvate.

Androecium

• Absent.

Gynoecium-Bicarpellary and syncarpous
Ovary-Inferior, unilocular
Placentation-Basal. 
Style -Simple
Stigma- Bifid.

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OTHER FLOWERS OF THE SAME FAMILY