The Anatomy of a Flower

Learning Objectives:

• To understand that the flower is the reproductive centre of the plant.
• To identify the key parts of the flower involved in reproduction.

What You Need:

• A selection of different flowers, particularly those with a ‘classic’ structure, such as hibiscus or lilium.
• A pair of tweezers
• A scalpel or another small, sharp blade
• Any magnification tools, such as a magnifying glass, viewer or microscope will also be helpful.

What to do:

Use the tweezers (or very gently, your fingers) to remove the petals on one side of the flower.

Use the diagram below as a guide to identify the following parts on your flower:

Anther: The parts that produce pollen grains. Each pollen grain contains a male sex cell. There will be more than one anther on the flower.

Filament: The long strands that attach the anthers to the base of the flower.

(The anther and the filament together make up the Stamen, the male part of the flower).

Style: A long column standing up in the centre of the flower.

Stigma: The end of the style. It produces a sticky substance for capturing pollen.

Ovary: Located at the other end of the style from the stigma. The ovary contains female sex cells, or ovules.

(The Style, Stigma and Ovary together make up the Pistil, the female part of the flower).

Sepals: Special leaves around the base of the flower. The job is to wrap around and protect the flower bud.

Receptacle: The base of the flower where all parts are attached.

Peduncle: The stem of the flower.

How does fertilisation happen?

When pollen grains get stuck to the stigma, a ‘pollen tube’ begins to form – a tunnel that goes down the style to the ovary. The male sex cells travel down the pollen tube to the ovary, where they fertilise the ovules (female sex cells). The fertilised ovules then develop into seeds. A fruit forms around the seeds.