Epidelia

Epidelia is a rarely used term referring to the outermost layer of cells or tissues in certain plant structures. It is most often associated with the protective covering of fruits and seeds. While sometimes used synonymously with epidermis, epidelia specifically emphasizes the external facing layer in these reproductive structures, distinct from the more general use of epidermis for leaves, stems, and roots. The term helps to differentiate between the protective layers of different plant organs and may be used to highlight specialized functions associated with the outer layers of fruits and seeds, such as preventing desiccation, pathogen attack, or regulating gas exchange. Its usage is generally limited to botanical research and technical literature.