A Grammatical Dictionary of Botanical Latin

Hesperidium, the fruit of species of the genus Citrus; citrus fruit, “a many-celled superior indehiscent fruit, pulpy within, and covered by a separable rind [i.e. the peel]; as the Orange” [Citrus, Rutaceae] (Lindley); “Desvaux’s term for a fruit, such as the orange: a superior, polycarpellary syncarpous berry, pulpy within, and externally covered with a tough rind; “Aurantium” of DeCandolle” (Jackson) [name derives “from the golden fruit of the garden of the Hesperides” (Jackson)]; “a thick-skinned septate berry with the bulk of the fruit derived from glandular hairs, as in Citrus” (Radford et al. 1974); [“NL, fr. the Hesperides “a berry (as an orange or lime) having a leathery rind” (WIII); see albedo,-inis (s.f.III); see aurantium,-ii (s.n.II); see flavedo,-inis (s.f.III); see hesperus,-i (s.m.II).

A specialized berry, with a leathery rind or “peel,” which is composed of three layers:

Outermost: the epicarpium,-ii (s.n.II) or exocarpium,-ii (s.n.II), called the flavedo,-inis (s.f.III), where reside the essential oils, paraffin waxes, bitter essences, etc. Commonly called the ‘zest.’ The exposed waxy, pigmented epidermal layer contains chromoplasts.

Middle: the mesocarpium,-ii (s.n.II), between the outermost and innermost layers of the pericarp or peel, consists of the albedo (albedo,-inis (s.f.III). A spongy flesh commonly called the ‘pith.’

Innermost: the endocarpium,-ii (s.n.II), wherein lie the locules (sections, segments) with their juice vesicles, commonly called the ‘pulp.’

Aurantium,-ii (s.n.II), abl. sg. aurantio: “a succulent superior fruit with a rough rind, such as the Orange” [Citrus; Rutaceae] (Jackson), used by DeCandolle (Jackson); note that DeCandolle seems to use this word as we would use of a fruit: ‘an orange;’

- [Dillenia] fructus aurantii forma et magnitudine (DeCandolle), the fruit with the form and size of an aurantium [i.e. orange; hesperidium or citrus fruit]

NOTE: Hesperidium was used as a generic name, as in Hesperidium triste (L.) Beck. after Hesperis tristis L.