Definition of Calyx

Outermost whorl formed by sepals of the flower in angiosperm plants.

More About Calyx

  • There are four whorls of a flower namely calyx, corolla, androecium, gynoecium
  • Calyx and corolla are the non reproductivenon-reproductive whorls whereas, androecium and gynoecium are the reproductive whorls
  • The calyx is the outermost non reproductive whorl of the flower
  • Calyx is formed by units called sepals, that are leaflike structure usually green in colour
  • The main function of the calyx is to protect the delicate inner whorls in the bud and support it during the opening of the flower
  • After the full bloom of the flower, it is located at the base of the flower
  • It protects the flower from desiccation
  • When the calyx becomes brightly coloured, then it is known as ‘petaloid’
    Example: Fuschia plant
  • When the sepals of the calyx fall off after the opening of the flower, the calyx is termed as caudcous
    Example: Argemone
  • When the sepals are bound to the fruit and do not fall off, then the calyx is said to be persistent
    Example: Brinjal
  • When a whorl of bracteoles is attached to calyx, it is known as epicalyx
    Example: Hibiscus

There aretwo main types of calyx

1) Gamosepalous calyx:

In this condition the sepals are partly or completely fused with each other
Example: Flowers of Datura and Hibiscus (China Rose) plant

2) Polysepalous calyx:
In this condition the sepals are free or seperate from each other, the calyx is said to be Polysepalous.
Example : Rose plant.