Fruit development

A fruit is a grown ovary. After the ovule in an ovary is fertilized in a method known as pollination, the ovary begins to ripen. The ovule develops into a seed and the ovary wall pericarp may become thickset (as in berries or drupes), or form a hard outer covering (as in nuts). In a few cases, the sepals, petals and/or stamens and style of the flower fall off. Fruit growth continues until the seeds have matured. With some multiseeded fruits the extent to which the flesh develops is comparative to the number of fertilized ovules.

The wall of the fruit, developed from the ovary wall of the flower, is known as the pericarp. The pericarp is regularly differentiated into two or three distinct layers called the exocarp (outer layer - also called epicarp), mesocarp (middle layer), and endocarp (inner layer). In some fruits, specially simple fruits derived from an inferior ovary, other parts of the flower (such as the floral tube, including the petals, sepals, and stamens), fuse with the ovary and ripen with it. When such other floral parts are an important part of the fruit, it is called an accessory fruit. Since other parts of the flower may donate to the structure of the fruit, it is important to study flower structure to understand how a particular fruit forms.