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What is the difference between the calyx and the corolla of a flower?
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Plant reproductive system
A large bumblebee (Bombus species) pollinating a teasel flower head (Dipsacus species).
The calyx and the corolla are the two outermost, accessory whorls of a flower, collectively forming the perianth. While both are sterile appendages not directly involved in sexual reproduction, they differ in their composition, appearance, and primary functions.123
- Calyx: This is the outermost whorl, consisting of individual units called sepals. Sepals are typically green and leaflike, serving primarily to enclose and protect the developing flower bud. In some species, the calyx remains persistent even after the fruit matures.123
- Corolla: Located internal to the calyx, the corolla consists of petals. These are generally larger and more brightly colored or white, serving to attract pollinators such as insects and birds. The corolla also defines the symmetry of the flower.34
In some plants, if the sepals and petals are similar in color and appearance, they are collectively referred to as tepals.123