Vascular bundle is a strand of special vascular tissue in plants that is a part of the transport system in vascular plants. It is composed of two complex tissues, xylem and phloem, and sometimes a layer of cambium cells. Xylem transports water and dissolved minerals from the roots to other parts of the plant, while phloem moves sugars produced during photosynthesis from the leaves to other parts of the plant. Cambium cells divide to produce new xylem and phloem as the plant grows, contributing to rings in trees and the layers of bark in woody plants. The different types of vascular bundles are open (with cambium) and closed (without cambium), radial, conjoint, and concentric. Vascular bundles are found in both the stem and leaves of a plant, and they vary in size and number depending on the species.