An avascular bundle is that part of the transport system in vascular plants which has two tissues. The vascular bundle comprises the xylem and phloem. In any vascular bundle, the xylem transports water and minerals from the roots to all the parts of the plant and phloem transports nutrients from leaves to all parts of the plant.   In a monocot leaf, many small and large-sized vascular bundles are present, whereas, in a dicot leaf, vascular bundles are generally large.