hesperidia

Hesperidia (plural of hesperidium) are a category of fleshy fruits typical of the citrus lineage in the family Rutaceae. In botanical terms, a hesperidium is a modified berry with a leathery rind (exocarp) and a segmented interior composed of juice-filled vesicles formed from the pericarp. The rind is often aromatic due to oil glands, and the inner rind layer (the albedo) is usually pale and fibrous. Inside, the fruit is divided into segments by septa; each segment contains numerous juice sacs derived from the endocarp. Hesperidia are typically indehiscent, adapted for dispersal by animals that consume the juice vesicles.

Most familiar citrus fruits—orange, lemon, lime, grapefruit, mandarin, and kumquat—are hesperidia. The term is used in botany to classify this particular fruit morphology rather than to name a single taxonomic group; all true hesperidia arise from a leathery-skinned, segmented fruit within the citrus lineage, though not every Rutaceae fruit is a hesperidium.

Taxonomic note: Hesperidium describes a fruit form rather than a single genus. It is characteristic of several genera in Rutaceae, including Citrus, and is often discussed in contrast with other fruit types such as berries, drupes, or pomes. In horticulture and food science, the structure of hesperidia influences peeling ease, rind flavor, and juice yield.