Floral whorls of flower- Definition, Meaning

The whorls are the set of leaves, branches and flowers that arise at the same height or from the same node, relative to the stem of the plant. These formations of the different organs of the plant have a structural as well as a reproductive role, especially when it comes to the floral whorls.

In this article we will tell you in detail about the morphology of plants.

What are Floral Whorls and Whorled Leaves?

Before we start to explain in depth what floral whorls are, it is important to know that other plant organs (like leaves or branches) also form whorls.

Whorled leaves

Thus, we can classify plants according to the arrangement of their leaves: leaves alternate or arranged around the stem and whorled leaves, those which are arranged in whorls or which are born at the same node.

Floral whorls

The flower is the most characteristic reproductive structure of phanerogamic plants. The flowers are made up of a set of modified leaves that are born after the plant has reached its adult stage and are usually distinguished by their coloring. 

Thus, we can distinguish several main parts: the peduncle, the calyx, the corolla, the androecium and the gynoecium . All of these structures that make up the flower are known as floral whorls.

Thus, as for the leaves, it is possible to classify the flowers according to their whorls:

• Achlamydeous: these flowers are devoid of perianth, and they are also called naked flowers.
• Chlamys : perianth flowers, also called dressed flowers.

In turn, the flowers are also distinguished from each other on the basis of their perianth. Remember that the perianth is the set of floral sheaths that protect the reproductive organs of the flower, that is to say the calyx and the corolla. Thus, the flowers are divided into several categories:

• Monochlamydeous, when they have only the calyx and a single whorl.
• Dichlamydeous, when they have two whorls in the perianth.
• Homochlamydeous, when they have two similar whorls.
• Heterochlamydeous, when the corolla and calyx are both differentiated.

What are the floral whorls and their parts?

We are now going to talk about the floral whorls or structures that make up what is called a flower. We will classify them into two groups:

• Androecium and gynoecium : these two floral whorls can be alone or coexist.
• Calyx and corolla : these two leafy pieces make up what is called the perianth.

Androecium

It is the male sexual organ of the flower. It is formed from the stamens which, in turn, have a filament with a closed sac at the end which is called the anther. The anther is responsible for storing pollen. The stamens can be united or free and can be grouped in the following ways:

• Monadelphous stamens , which are united by the filaments into a single bundle.
• Philadelphia stamens are those that have two bundles.
• Polyadelphous stamens are those that have more than two bundles.
• Syngeneic stamens are stamens united by anthers into a single bundle.
• Didynamous stamens composed of two long and two short stamens.
• Tetradynamous stamens composed of four long and two short stamens.

Gynoecium

This is the female sexual organ that contains corpuscles whose function is to produce what we call seeds. The gynoecium, which is formed of capillaries, contains the ovary, style and stigma. The stigmas can be classified as follows

• Monocarpellary when it consists of a single carpel sheet, which is also fused to itself.

• Pluricarpellar , when it consists of several carpel leaves. In this case, they are also divided into two: syncarpous, when the leaves of the carpel are fused together, and apocarpous, when the leaves of the carpel are free.

Calyx

The calyx is formed by the sepals , modified leaves, usually greenish in color, which have a protective function. Depending on the arrangement of the sepals, we can differentiate them:

• Dialysepal, when they are free.
• Gamosepal, when they are fused together.

Corolla

The corolla is made up of the petals, which are leaves modified into attractive shapes and colors to attract pollination. As with the calyx, it is also differentiated into polypetalae and gamopetalae depending on whether the petals are free or united, respectively.

Other parts of the flower

Now that you know what whorls and their characteristics are, let's take a look at some other parts of the flower that you need to know:

• Peduncle : the last part of the stem that supports the flower is called the peduncle. The peduncle is a thin pedicel that connects the flower to the stem. When the flower has a peduncle, it is classified as a pedunculate flower. On the other hand, when it does not have a peduncle, it is called a sessile flower. It is usually green in color and cylindrical in shape, and can vary in size depending on the species.
• Receptacle : also called the floral axis, this is the enlarged part that follows the peduncle and where the rest of the floral whorls sit. That is to say the chalice, the corolla, the androecium and the gynoecium.