Ovary
The swollen base of the pistil that holds the ovules and later becomes the fruit.
The ovary is the chamber at the bottom of the pistil where the ovules, the future seeds, are kept. After fertilisation the petals fall and the ovary swells into a fruit. You can see this on a rose, where the ovary area ripens into a red hip, or on a courgette, where the young fruit is already visible behind the female flower. In daffodils and irises the ovary sits below the petals as a green bump on the stem.