vascular bundle

One of a number of strands of primary vascular tissue constituting the *vascular system of the plant.  Vascular bundles consist mainly of xylem and phloem, which may be separated by a *fascicular cambium. The relative position of xylem and phloem determines the type of bundle (collateral , *bicollateral , *concentric , *amphicribal , or *amphivasal ), and is often important taxonomically. The vascular bundles in a dictyostele are called *meristeles. See also eustele , atactostele.