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.

In plants, the tissue of unspecialized cells lying between the epidermis (surface cells) and the vascular, or conducting, tissues (see phloem and xylem) of stems and roots. Cortical cells may contain stored food or other substances, such as resins, latex, essential oils, and tannins. Cortical cells in herbaceous stems, young woody stems, and stems of succulents contain chloroplasts and can therefore make food by photosynthesis. Food, usually in the form of starch, in edible roots, bulbs, and tubers is stored mostly in the cortex.

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