Types of Flowers: Flower, Types of Flowers Based on Reproductive Structures, Length of a Stamen, Fusion of Stamen to Other Floral Parts, Free or United Stamen, the Fusion of Pistils, the Position of an Ovary and Symmetry, Practice Problems and FAQs

All of you like flowers. It is associated with our lives in many ways. Do you know flowers have a language too or they can convey messages? When we are giving a flower to someone it represents a message. For example, if we are giving a red rose to a person, it means we love that person. Similarly, if we are giving an aconite flower to someone, it means ‘beware’ of something. If we are giving Coronilla flowers to someone, it represents the message ‘all the best’. 

                                       Fig: Flowers

A flower is the most beautiful structure of a plant, hence it is considered as the ornament of the plant. It is the reproductive part of a plant. You know that all flowers do not look the same. They differ in their structure, colour, position etc. Do you know how many varieties of flowers are present, based on the difference in structures they possess? No, you are confused. Let’s find out the answer for this question in this article. So let’s take a deep dive into the details of flowers in detail in this article.

Table of contents

• Flower
• Types of flowers on the basis of reproductive structures
• Types of flowers on the basis of shape of different parts
• Types of flowers based on the length of a stamen
• Types of flowers based on the fusion of stamen to other floral parts
• Types of flowers based on free or united stamens
• Types of flowers based on the fusion of pistils
• Types of flowers based on the position of an ovary
• Types of flowers based on symmetry
• Practice Problems
• FAQs

Flower

The reproductive organ of a plant is its flower because they play a role in reproduction. They also provide food for other living things. They offer a plentiful supply of nectar to the organisms. Some flowers are edible. They provide pollen grains which can be consumed in most cases. 

Flowers can either be complete or incomplete. If a flower possesses sepals, petals, stamens, and pistils. It is called a whole flower. On the other hand, a flower that is missing one or more of these features is said to be incomplete. Therefore, it is said that a complete flower consists of all vegetative and reproductive parts. 

                                                             Fig: Complete flower

Types of flowers on the basis of reproductive structures

The flowers are classified into two categories on the basis of the presence or absence of reproductive structures. These are as follows:

• Bisexual flower
• Unisexual flower

Bisexual flower

In bisexual flower, both reproductive structures, androecium, and gynoecium are present in the same flower. The bisexual flowers are also known as monoecious flowers. Examples of the bisexual flowers include Hibiscus and passion fruit flowers.

                                                             Fig: Bisexual flower

Unisexual flower

In a unisexual flower, only one reproductive structure is present and that is either androecium or gynoecium. Therefore, they are known as staminate and pistillate flowers, respectively. The condition of a unisexual flower is also known as a dioecious. Examples include cucurbits.

                                                                  Fig: Unisexual flower

Types of flowers on the basis of shape of different parts

Flowers are divided into two types based on the shape, size, colour and origin of floral parts. They are as follows:

• Regular flower
• Irregular flower

Regular flower

In this type of flower all its floral parts of each series are similar in shape, size, colour and origin. Examples include lily flowers.

                                 Fig: Lily flower

Irregular flower

In this type of flower irregularity is shown in any of its floral parts in size, shape, colour and origin. Examples include butterfly pea flowers. 

                Fig: Butterfly pea flower

Types of flowers based on the length of a stamen

Based on the length of the stamen, two types of flowers are present. These are listed below:

• Didynamous
• Tetradynamous

Didynamous

Four stamens are arranged into two equal pairs of unequal length in this condition in a flower. Examples of didynamous flowers include Salvia and Ocimum.

              Fig: Didynamous flower

Tetradynamous

There are six stamens, four of which are long and two of which are short in this condition. Examples include the mustard flowers.

              Fig: Tetradynamous flower

Types of flowers based on the fusion of stamen with other floral parts

According to how the stamen blend with other floral components, the flowers are divided into two types:

• Epipetalous
• Epiphyllous

Epipetalous

In the epipetalous type of flower, the stamens are attached to the petals. Examples include brinjal flowers.

                                                 Fig: Epipetalous flower

Epiphyllous

In epiphyllous types of flowers, the stamens are attached to the perianth (whorl of tepals). An example of such a condition is a lily flower.

                       Fig: Epiphyllous flower

Types of flowers based on free or united stamen

According to the condition, whether the stamens are free or joined, the flowers are divided into two types as follows:

• Fused stamens (Cohesion of stamens)
• Polyandrous

Fused stamens

The stamens are joined together in this state. Androecium of a flower with five fused stamens is denoted as A(5). This condition is also known as adelphous. 

Adelphous

The stamens are only joined by their filaments in this state. They are of three varieties as follows:

• Monadelphous
• Diadelphous

• Polyadelphous

Monadelphous

Stamens unite to form a single group here. China Rose is an example of this condition.

                 Fig: Monadelphous

Diadelphous

Stamens fused to form two bundles or groups in this condition. Pea flower is an example.

                                            Fig: Diadelphous

Polyadelphous

Stamens united to form many bundles here. Citrus flowers are an example of this condition.

                                                        Fig: Polyadelphous

Polyandrous

The stamens are free in the polyandrous flower. Lotus flower is an example for this condition.

                                            Fig: Polyandrous

Types of flowers based on the fusion of pistils

On the basis of the arrangement or fusion of pistils, the flowers are divided into three categories. These are as follows:

• Monocarpous
• Apocarpous
• Syncarpous

Monocarpous

Only one carpel or pistil is present in the monocarpous flower. Examples include wheat flowers.

                                                     Fig: Monocarpous flower

Apocarpous

Multiple carpels are present and are free in this type of flower. G5 represents a flower with five free carpels. Lotus and rose are examples for this condition.

                      Fig: Apocarpous flower

Syncarpous

There are several carpels present, but they are all connected in this condition. G(5) represents a flower with five joined carpels in the gynoecium. Tomato and mustard flowers are examples for this condition.

                        Fig: Syncarpous flower

Types of flowers based on the position of an ovary

Based on where the ovary is located, there are three different types of flowers. These are listed below:

• Hypogynous
• Perigynous
• Epigynous

Hypogynous

The gynoecium is located at the top of the flower. Below the gynoecium located are the calyx, corolla, and androecium in this condition. The ovary is located at the superior position and is represented with a symbol G. Hibiscus, mustard flowers, and brinjal flowers are some examples.

           Fig: Superior ovary

Perigynous

The position of the gynoecium is in the centre, a little lower than the other floral whorls. Other floral parts are located on the rim of the thalamus, almost at the same level. The ovary is located at the half-inferior position and is represented with a symbol G-. Rose, plum flowers, and peach flowers are some examples of this condition.

                                  Fig: Half-inferior ovary

Epigynous

The margin of the thalamus grows upwards and encloses the ovary. It fuses with the ovary. Above the ovary other parts like the calyx, corolla, and androecium are present. The ovary is situated inferior. Sunflower ray florets, guava flowers, and cucumber flowers are a few examples of this condition.

     Fig: Inferior ovary

Types of flowers based on symmetry

Symmetry is the ability to split flowers into equal halves. Based on symmetry, flowers are categorised into three types as follows:

• Actinomorphic
• Zygomorphic
• Asymmetric

Actinomorphic

Actinomorphic flowers can be cut in any plane to two equal halves. They show radial symmetry. It can be represented using the symbol ‘⊕’. Examples of actinomorphic flowers include mustard flowers, Datura flowers, and chilli flowers.

              Fig: Actinomorphic flower

Zygomorphic

Zygomorphic flowers can be cut into two equal halves only through one plane. They show bilateral symmetry. It can be represented by the symbol ‘%’. Examples of such flowers are Gulmohar, cassia, pea, and bean flowers.

                    Fig: Zygomorphic flower

Asymmetric

Asymmetric flowers cannot be normally divided into equal halves in any plane. An example of such a flower is Canna.

                       Fig: Asymmetric flower

Practice Problems

Q 1. Identify the flower in which radial symmetry is found?

a. Cassia  
b. Brassica
c. Trifolium
d. Pisum 

Answer: A flower is said to be radially symmetrical if it can be split in equal halves evenly by a plane that passes through the centre. For example, the mustard family includes the genus Brassica. Datura and chilli flowers are other examples. Hence, the correct option is b.

Q 2. When all of the stamens of a flower joints by its filaments to form a single bundle, the situation is known as ______________.

a. monandrous 
b. monadelphous 
c. diadelphous 
d. polyadelphous

Answer: When all of the stamens of a flower joints by its filaments to form a single bundle, the situation is known as monadelphous. The staminal column is a single bundle made up of all the filaments of the stamens in the Hibiscus rosa-sinensis (China rose) flower. Monadelphous condition is the name given to this condition. Hence, the correct option is b.

Q 3. Identify the plants in which perigynous flowers are found?

a. Rose 
b. Guava 
c. Cucumber 
d, China rose

Answer: A rose flower is an example of a perigynous flower. It is referred to as perigynous because the gynoecium is in the centre and other floral parts are situated close to the level of the rim of the thalamus. In such flowers, the ovary will be half inferior. Hence, the correct option is a.

Q 4. Identify the flower in which the half-inferior ovary is present?

a. Guava
b. Peach
c. Cucumber
d. Cotton 

Answer: The gynoecium is found in the centre of flowers like roses, peaches, and plums, whereas other components of the flower are situated on the thalamus rim almost at the same level (perigynous). The ovary is thought to be half inferior in this condition. Hence, the correct option is b.

FAQs

Q 1. Which flower is considered as the “king of the flowers”?
Answer: Since the Tang Dynasty, the peony flower has been referred to as the "king of flowers." The aestheticism of the Tang Dynasty was one of plenty and rich beauty. The peony was an obvious choice to be the "lord of flowers" due to its large, glittering petals and strong aroma.

Q 2. Why are flowers so special to humans?
Answer: Each flower is distinctive in terms of size, colour and shape. They are associated with different religions and cultures. In all ceremonies flowers are used. Due to all these flowers are more unique than any other plant parts.

Q 3. How long do flowers remain fresh after being harvested?
Answer: Most of the plucked flowers can remain fresh anywhere from 7 - 12 days.

Q 4. Why do some flowers have no scent?
Answer: Scent is not always necessary for flowers. When pollination is carried out by a pollinating agent like insects or small birds, scent or smell is required. However, no fragrance is required when pollination happens by wind or water.

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