Question

Give examples of the tetramerous and pentamerous flower.

Answer 1

Hint: Merosity is referred to as the number of component parts in a distinct whorl of a plant. It basically denotes the number of sepals in a whorl of the calyx, the number of petals in a whorl of the corolla, or even the number of carpels in a whorl of the gynoecium. The term can also be used to refer to the number of leaves in a leaf whorl.

Complete answer:
A typical flower has a circular section with a common centre that can be clearly observed and distinguished from the top of the flower. The calyx is the outermost whorl of a flower that comprises sepals which are basically tiny leaves situated at the base of a flower. Corolla is the second whorl of a flower that comprises petals. Both the calyx and corolla are together called the perianth.

In a tetramerous flower, the floral parts are arranged in four or even multiples of four in such a way that each whorl of flower parts has four flower parts An example is Brassica juncea

The diagram below shows Tetramerous flower

In pentamerous flower, the floral parts are either arranged in five or even multiples of five. An example is Hibiscus, Dicots.

The diagram below depicts Pentamerous flower

Note: If all the whorls in a given floral arrangement have the same merosity, the flower is called isomerous, if the floral arrangement does not have the same merosity the flower is known as anisomerous. There are Trimerous flowers also where the floral parts are arranged in three or multiples of three, an example is Polyanthus.