Define inflorescence and describe its various types



Define inflorescence and describe its various types.
Define the term inflorescence. Explain the basis for the different types of inflorescence in flowering plants.


Inflorescence: An axis bearing a cluster of flower is called an inflorescence.
The main types of inflorescence are :

  1. Racemose : This is further divided into (a) Raceme,
    (b) Catkin, © Spike, (d) Spadix, (e) Corymb, (f) Umbel, (g) Head or Capitulum.
  2. Cymose : It is further divided into (a) Monochasial Cyme, (b) Dichasial Cyme, © Polychasial Cyme. Various type of racemose inflorescence :
  3. Typical raceme : It is characterized by elongated axis bearing stalked flowers laterally in an acropetal manner. Older flowers are lower (having long stalks) while younger flowers are above (having short stalks), e.g., Gulmohar and larkspur.
  4. Corymb : The flowers having varying length of pedicels but come to the same level e.g., cauliflower and candituft.
  5. Spike: The flowers are sessile i.e., have no stalk, e.g.,grasses.
  6. Umbel: The main axis is short and all the flowers arise from the same point appearing like an umbrella, e.g., coriander.
  7. Catkin : The flowers are sessile and contain only of one type either male or female e.g., mulberry.
  8. Hypanthodium : The flask-shaped receptacle has all the flowers. There is only one pore at the tip. The cup like receptacle bears unisexual flowers on its inner wall, e.g., Ficus.
  9. Spadix: All the flowers are enclosed in a large bract called spathe. Unisexual small flowers occur in different groups on the thick axis, e.g., Banana.
  10. Capitulum : It is called head inflorescence. The main axis is flattened. Receptacle is short. Ray florets arise on it in centripetal order. An involurce surrounds the whole inflorescence. It bears ray and disk florets, e.g., Dahlia and sunflower. (It is an inflorescence and not a flower).