What is Calyx?

Table of Contents

Calyx Meaning

The outermost whorl of the flower is referred to as the calyx. Sepals are the functional units of the calyx, meaning that the calyx is a collection of sepals. The sepals are mostly green in colour and protect the inner structures of the flower from breakage, mechanical injury and desiccation. It supports the other internal structures of flowers such as the corolla, gynoecium and androecium. Corolla is the collection of petals, androecium is the male reproductive whorl and gynoecium is the female reproductive whorl of the flower.

The calyx is found just below the corolla. In some plants, the calyx and corolla are indistinguishable and are termed as perianth. Once the flower has bloomed, the calyx goes on to support the development of fruit. Sometimes, an additional whorl is found externally to the calyx that consists of a whorl of bracts that arise by the union of sepal appendages.

Forms of Calyx

  • Polysepalous: When the calyx consists of sepals that are free from each other, it is referred to as polysepalous. E.g., Rose, Cassia
  • Gamosepalous: When the sepals are fused in the calyx, it is referred to as gamosepalous. E.g., Datura
  • Caducous: When the sepals of a flower wither or drop off, it is referred to as caducous. E.g., Poppy
  • Petalloid: In petalloid conditions, the sepals of the flowers are coloured. E.g., Delphinium
  • Persistent: In this form, the sepals do not wither and are persistent even in the fruits. E.g., Brinjal

Difference between Calyx and Corolla




The whorl of sepals is known as calyx.

The whorl of petals is known as corolla.


It is the outermost whorl of the flower.

It occurs inside the calyx.

Functional Unit




It is usually green in colour.

It has vibrant colours.


It protects the interior whorls of the flower from mechanical injury.

It attracts pollinators for pollination.

Keep visiting BYJU’S Biology for more updates.

Also Read:

Frequently Asked Questions


Epicalyx is a characteristic feature of which family?

The presence of epicalyx is the characteristic feature of the Malvaceae family.

What is the function of calyx in flowers?

The calyx functions to protect the flower while it is in the bud stage.