Search in gallery Transverse section of the outer portion of the Allium root - Large (114 Kb) - Scroll down   to information With labels Legend: 1  epidermis 3  cortex 2  exodermis   English name: Onion Scientific name: Allium cepa Familia: Liliaceae Classis: Monocotyledonas Phylum: Angiospermae Regnum: Plantae The epidermis is and the exodermis, the outer layer of cortical cells, has taken over the function of the epidermis.

http://www.vcbio.science.ru.nl/en/image-gallery/show/PL0187/print/