Hesperidium

Overview

A hesperidium is a type of berry with a leathery rind. It is a fruit characteristic of the Rutaceae family, which includes the citrus genus. The term "hesperidium" is derived from the Hesperides, the nymphs of the evening in Greek mythology, who were said to guard a garden of golden apples.

Structure

Diagram of an orange, a typical hesperidium

The structure of a hesperidium is unique among fruits. It consists of several distinct layers:

• The outermost layer is the exocarp, commonly referred to as the peel or rind. This layer is leathery and contains oil glands that give citrus fruits their characteristic aroma.
• Beneath the exocarp is the mesocarp, also known as the albedo or pith. This layer is spongy and white, providing a cushion for the inner parts of the fruit.
• The innermost layer is the endocarp, which is divided into segments. Each segment contains juice-filled vesicles, which are the edible part of the fruit.

Development

Hesperidia develop from a single ovary and are classified as simple fruits. During development, the ovary wall thickens to form the protective rind, while the inner tissues differentiate into the juicy segments. The oil glands in the rind develop from specialized cells that produce volatile compounds, contributing to the fruit's fragrance.

Examples

Common examples of hesperidia include:

• Oranges
• Lemons
• Limes
• Grapefruits
• Tangerines

Uses

Hesperidia are widely consumed for their juicy segments, which are rich in vitamin C and other nutrients. The rind is often used for its aromatic oils in cooking and perfumery. Additionally, the pith can be used in marmalades and other culinary applications.

Related pages

• Berry
• Citrus
• Fruit anatomy
• Rutaceae