Vascular bundle, which possess both xylem and phloem are called conjoint vascular bundle. In bicollateral conjoint vascular bundle phloem present on both outer and inner side of xylem, eg, Cucurbita. In collateral conjoint vascular bundle the phloem present on outside of xylem, eg, gymnosperm and dicot stem. In concentric conjoint vascular bundle one type of vascular tissue surround the other completely. In radial vascular bundles the phloem and xylem occur as distinct bundles present on alternate radii, eg, roots.