Difference Between Calyx and Corolla

The key difference between calyx and corolla is that calyx is the collection of sepals while the corolla is the collection of petals of a flower.

Flowers are the reproductive structures of flowering plants. They have several parts – petals, sepals, stamen, and carpel are the main parts. Each part performs distinct functions. Complete flowers have all four parts, while incomplete flowers lack one or more parts. The carpel is the female reproductive organ of the flower while stamens are the male reproductive organs. Petals are the most colourful parts. They surround the reproductive organs. Petals are collectively called the corolla. Corolla helps to attract pollinators. Sepals are modified leaves that enclose the developing flower. Sepals are collectively called the calyx. Calyx protects the flower bud. It also provides structural support to a flower.

CONTENTS

1. Overview and Key Difference
2. What is Calyx 
3. What is Corolla
4. Similarities Between Calyx and Corolla
5. Side by Side Comparison – Calyx vs Corolla in Tabular Form
6. Summary

What is Calyx?

The calyx is the outermost whorl of the flower composed of sepals. Therefore, the collection of sepals is known as the calyx. The sepal is the unit of the calyx. Calyx is mostly green in colour. It has a leaf-like structure. The calyx is present just beneath the corolla. Together, the calyx and corolla is called the perianth. Calyx protects the flower bud and the developing flower. Especially, it protects the petals and supports petals when blooming.

Moreover, calyx provides structural support to the flower. After flowering, calyx has no more use. In some flowers, the sepals are fused towards the base, forming a calyx tube.

What is Corolla?

Petals are the modified leaves which are colourful. They protect the reproductive parts of the flower. Collection of petals of a flower is called the corolla. Therefore, the petal is the unit of a corolla. Corolla is brightly colourful in almost all flowers. Since corolla is colourful, it helps the flower to attract pollinators such as birds and insects.

Moreover, in many flowers, the corolla produces different scents to attract pollinators. Shape and the size of the corolla also influence pollination. A large corolla is visible for a large distance for pollinators. Corolla is present just above the calyx

What are the Similarities Between Calyx and Corolla?

• Calyx and corolla are the two main parts of a flower.
• Calyx and corolla together make up the perianth.
• They are seen in flowering plants.
• Both can be colourful.
• They are important parts of a flower, and they perform distinct functions.
• Calyx is present just beneath the corolla.
• Both corolla and calyx are comprised of modified leaves.
• When corolla and calyx are not well distinguishable, they are collectively called tepals.

What is the Difference Between Calyx and Corolla?

The calyx is the outermost whorl of a flower composed of sepals while the corolla is the collection of petals. So, this is the key difference between calyx and corolla. The unit of a calyx is a sepal while the unit of a corolla is a petal.

Moreover, calyx protects the flower bud and provides structural support to the flower whereas corolla protects the reproductive parts of the flower and aids in pollination. Thus, this is a functional difference between calyx and corolla.

Below infographic tabulates more differences between calyx and corolla.

Summary – Calyx vs Corolla

Calyx and corolla are two important parts of a flower. They are together called perianth. Calyx is the collection of sepals while the corolla is the collection of petals of a flower. Calyx basically protects the developing flower and provides structural support to the flower. In contrast, corolla protects the reproductive organs of the flower and attracts pollinators. Calyx is mostly green in colour while the corolla is colourful most of the time. Thus, this summarizes the difference between calyx and corolla.

Reference:

1. “Sepal”. En.Wikipedia.Org, 2020, Available here.
2. “Flower Structure | Biology For Majors II”. Courses.Lumenlearning.Com, 2020, Available here.

Image Courtesy:

1. “Vicia February 2008-1” By Alvesgaspar – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Geranium incanum 9156s” By JonRichfield – Own work (CC BY-SA 3.0) via Commons Wikimedia