What are medullary rays and what are their functions?

• Medullary rays are strips of parenchyma present between vascular bundles of dicot stem. They separate xylem and phloem bundles.
• They serve as a link between pith and cortex. They are also known as pith rays and vascular rays.
• They perform various functions like food storage, storage of tannins, transport of food and water, gaseous exchange, etc.