The Columbia Encyclopedia, Sixth Edition. 2001-07.
cortex
in botany, term generally applied to the outer soft tissues of the leaves, stems, and roots of plants. Cortical cells of the leaves and outer layers of nonwoody stems contain chloroplasts, and are modified for food storage (usually in the form of starch) in roots and the inner layers of stems and seeds. Because of the combination of its soft texture (especially after cooking) and its role as a food storage tissue, the cortex is the predominant plant tissue eaten by humans and other animals.
