What the flower becomes
After fertilisation the zygote is formed, and it develops into an embryo. A series of changes then takes place in the flower.
| Part of the flower | Becomes |
|---|---|
| Ovary | The fruit |
| Ovary wall | The pericarp |
| Fertilised ovules | The seeds |
| Integument of the ovule | The seed coat |
Generally, the sepals, petals, stamens and stigma fall away at this point. Their work is finished: the flower no longer needs protecting or advertising.
The exception
In some flowers the sepals do not fall even after fertilisation. They become fleshy and remain fused with the pericarp — so part of what you eat was never the ovary at all.
Examples — guava, rose apple, brinjal, mangosteen.
One ovary, one fruit; one ovule, one seed
This is why a papaw, with many ovules in one ovary, is a single fruit full of seeds, while a mango, with one ovule, is a single fruit with one seed. Count the seeds in a fruit and you have counted the ovules that were fertilised.