Structure of Sepals
Sepals are the green-coloured vegetative structures, which are a characteristic feature of flowering plants better known as the angiosperms. Sepals are located at the base of the flower, forming the outermost whorl, often encircling and protecting the developing bud and are collectively termed as the calyx. Unlike petals, which are usually soft and colorful, sepals are often tougher and less conspicuous. In a complete flower, i.e. one which has all the four floral parts (sepals, petals, stamen and carpel), the sepals are attached to the floral stalk by a receptacle.
The sepals mainly comprise the:
- parenchyma
- secretory cells known as laticifers
- tannin cells and
- other specialized plant cell organelles
Though sepals are mainly green, they can also be of varied colors depending on the plant species. Green coloured sepals contain plastids that contain chlorophyll, better known as chloroplasts along with the differentiated palisade and spongy mesophylls. Both monocots and dicots have sepals, but the difference lies in the number of sepals present in the flowers of monocots and dicots. The monocots have floral parts in the multiples of three whereas dicots tend to have floral parts in the multiples of four or five. Hence, the monocots are termed trimerous and the dicots on the other hand are termed as tetramerous or pentamerous.
Also Read: Anatomy of Flowering Plant
The Role of Sepals in Flower Development and Protection
Sepals are small leaf-like green outermost part of flowers. Together, they form the outermost whorl of a flower. This whorl is called the calyx. Sepals function as protective structures that cover the bud and provide structural integrity to the petals that form the corolla. There are different types of sepals based on their shapes and modifications. Some commonly observed examples of sepals include the urn-shaped green structure at the base of Hibiscus, marigolds, etc., and a cap-like green structure at the top of brinjal, tomato, etc.
Table of Content
- What is Sepal?
- Structure of Sepals
- Types of Sepals
- Functions of Sepals
- FAQs – Sepals