Hesperidium

Hesperidium, so named from the legend of the golden apples of the Hesperides, is the technical term for the fruit of the orange tribe, a superior polycarpellary syncarpous succulent fruit, belonging to the nuculane type. It has a leathery epicarp, studded with oil-glands, a white woolly mesocarp and a thin membranous endocarp dividing the numerous carpels, which are each usually two-seeded. From the inner surface of this endocarp are produced rows of large spindle-shaped cells, filled with watery acid or sub-acid juice, which fill the carpels as the pulp of the fruit.