hesperidium

This botanical term describes the specific fruit structure of citrus plants. It is characterized by a thick, oily outer rind called a flavedo and a spongy inner layer known as the albedo, which together form a protective shell around the juicy pulp. Unlike a standard berry, the interior of this fruit is partitioned into distinct segments containing juice-filled vesicles. Because it is a technical scientific classification, it is used almost exclusively in botany and horticulture rather than in casual conversation.