Flower: Definition, Types, and Functions

Flower: Definition

Anthology refers to the study of flowers. The Flower may be defined as a modified condensed shoot meant to carry out sexual reproduction in Angiosperms (Goethe). The flower is a highly condensed modified reproductive shoot. The stalk of the Flower is known as Pedicel and swollen part of the pedicel is known as the receptacle. At the center there is the presence of female reproductive part called Gynoecium, then male reproductive part Androecium, Another whorl called Petals, Group of petals are known as Corolla, After corolla, the outermost whorl called Sepals Group of sepals called the calyx.

Types of Flower

1. Complete Flower: If all the four whorls are present in the flower it is called Complete Flower (Gynoecium, Androecium, corolla, calyx).

2. Incomplete Flower: If any one of the four whorls are absent in Flower it is called Incomplete Flower (Gynoecium, Androecium, corolla, calyx)

3. Bisexual Flower: If a flower contains both male and female reproductive parts it is called Bisexual Flower.

4. Unisexual Flower: If Flower has only one reproductive part then it is called Unisexual Flower.

Pistillate Flower: If the only female part is present

Staminate Flower: If the only male part is present i.e. Androecium the flower is called Staminate Flower.

5. Dichlamydeous Flowers: If a flower contains both Calyx and Corolla it is known as Dichlamydeous Flower. It is most common in plants.

6. Monochlamydoeus Flower: If a flower contains only one whorl, the whorl which is present is known as perianth and this is seen in the case of monocot families e,g Liliaceae

7. Achlamydeous Flower: If Calyx and Corolla are absent in flower it is called Achlamydeous Flower.

Types of Flowers based on Symmetry

It is of the following types

1. Actinomorphic Flower: If Flowers can be cut into two halves by any vertical plane passing through the center such types of Flowers are known as Actinomorphic Flowers. This type of condition is shown by the Malvaceae family, China rose, Brassicaceae family Mustard, Solanaceae family Dutara.

2. Zygonorphic Flower: If flowers can be cut into two halves by one vertical plane passing through the center it is called a Zygonorphic Flower.

3. Asymmetrical Flower:  Asymmetrical Flowers are those that cannot be cut into two halves by any vertical plane running through the center. e,g Canna.

Types of Flowers on the position

1. Hypogynous Flower: These are those flowers in which Ovary (Gynoecium) is superior i.e. Ovary is at top and rest of the floral parts are developing from lower part i.e. they are inferior. Thus this type of flowers are known as Hypogynous Flowers e,g China rose, Mustard, Brinjal, etc

2. Perigynous Flowers: These are those flowers in which Gynoecium is Half Superior and Half Inferior e,g Peach, Plum, Rose, etc.

3. Epigynous Flowers: These are those flowers in which Ovary (Gynoecium) is inferior and the rest of the floral parts arise from above the ovary. Thus this type of flowers is known as Epigynous flowers e,g Guava, Cucumber, etc

Functions of Flowers

1. The flower is a highly condensed modified reproductive shoot meant for sexual reproduction.

2. Flowers helps diverse modes of pollination

3. Flowers help for germination of pollen, development of pollen tube, formation of gametes, and fertilization.

5. The calyx helps in the dispersal of fruits and seeds.

Important Points to be remember

1. Dioecious plants: In this, the male and female parts are present on different plants e,g Date palm, Mulberry, Papaya, etc.

2. Opening of Flowers called Anthesis

3. Cultivation of flowers called Floriculture

4. Parts of typical flower Pedicle, Thalamus, Calyx, Corolla, Androecium, Gynoecium.

5. Aggregation of sepals called Calyx

6. Aggregation of Petals called Corolla

7. Aggregation of Stamens called Androecium

8. Aggregation of carpels called Gynoecium

9. Polysepalous means sepals free e,g Mustard

10. Gamosepalous means sepals fused e,g Brinjal

11. Polypetalous means Free petals e,g Rose

12. Gamopetalous Fused petals e,g Burseraceae Family

13. The arrangement of sepals and petals for each other is called Aestivation

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