The plant cortex is the tissue located between the vascular bundles and epidermis. The cortex is responsible for the storage of photosynthetic products and the uptake of water and minerals. It also consists of a large amount of thin-walled parenchyma cells, which maintain the structure of a plant.
According to Wikipedia, the cortex is the outermost layer of the stem or root of a plant. It transports materials into the central cylinder of the root through diffusion and stores food in the form of starch. The cells inside the cortex may also contain stored carbohydrates or other substances such as resins, latex, essential oils and tannins. The cortex typically develops into a porous tissue called aerenchyma, which contains air spaces produced by separation and tearing of the cortex cell walls. Cortical cells also contain chloroplasts, which can convert carbon dioxide and water into simple carbohydrates using photosynthesis. In addition, cortex cells beneath the epidermis produce waterproof cells known as cork, which replace the epidermis on woody stems and roots. The bark of trees consists of cork, cortex and phloem. In fleshy stems such as carrots, beet, turnips and radishes, the cortex is located in the area between the vascular bundles and the epidermis.