Difference Between Androecium and Gynoecium

In the study of plant reproduction under the chapter Morphology of Flowering Plants, the structure and function of the male and female reproductive parts are essential topics. These reproductive whorls are known as the androecium and gynoecium, and together they form the reproductive system of a flower. 

What Is an Androecium?

• The androecium is the male reproductive whorl of a flower. 
• It consists of stamens, and each stamen participates in the production and release of pollen grains that contain male gametes.

Structure of a Stamen

A typical stamen consists of:

• Anther:
  Typically bilobed and contains microsporangia where pollen grains develop. The pollen grains carry male gametes.
• Filament:
  A slender stalk that supports the anther
• Holds the anther in a suitable position for pollen release and pollinator contact
• Connective Tissue that connects the two lobes of the anther.

Types of Stamens Based on Attachment

• Epipetalous (attached to petals): Example – Solanum
• Epiphyllous (attached to perianth): Example – Lilium

Variation in Androecium Arrangement

Stamens may be:

• Polyandrous: Free stamens
• Monadelphous: Filaments fused into one bundle (e.g., China rose)
• Diadelphous: Fused into two bundles (e.g., pea)
• Polyadelphous: Fused into multiple bundles (e.g., citrus)

Function of Androecium

• Produces pollen grains containing male gametes
• Assists in pollen transfer during pollination
• Supports the reproductive cycle by enabling fertilisation

1.0What Is a Gynoecium?

• The gynoecium is the female reproductive whorl of a flower and is located at the centre. 
• It consists of one or more carpels, each containing the female gametophyte (embryo sac).

Structure of a Carpel

A single carpel includes:

• Stigma – Sticky structure that receives pollen during pollination.
• Style – Elongated stalk connecting stigma to ovary.
• Ovary – Enlarged basal portion containing ovules, which develop into seeds after fertilisation.

Types of Gynoecium Based on Carpel Number

• Monocarpellary: One carpel (e.g., pea)
• Multicarpellary: Multiple carpels (e.g., rose)

Types Based on Fusion

• Apocarpous: Carpels free (e.g., Michelia)
• Syncarpous: Carpels fused (e.g., mustard)

Function of Gynoecium

• Produces female gametes within ovules
• Facilitates fertilisation through pollen tube formation
• Develops into fruit and seeds after fertilisation

2.0Androecium vs Gynoecium: Key Differences

3.0Structural and Functional Relationship Between Androecium and Gynoecium

Although distinct in structure and function, both whorls work together during fertilisation:

1. Pollination transfers pollen from the anther to the stigma.
2. Pollen germinates and forms a pollen tube through the style.
3. Male gametes reach the ovule inside the ovary.
4. Fertilisation occurs, leading to the formation of a seed and a fruit.

Thus, the coordination between the androecium and the gynoecium ensures successful sexual reproduction in angiosperms.

4.0Significance in Plant Classification

Both the androecium and gynoecium provide important classification criteria in taxonomy. Features such as:

• Position of the ovary (superior, inferior)
• Number of stamens and carpel fusion
• Type of aestivation or attachment

help in identifying plant families and analysing evolutionary relationships.