Conjoint and concentric vascular bundles refer to the arrangement of the different tissues that make up the vascular bundles in plants.
Conjoint vascular bundles have phloem and xylem tissues arranged adjacent to each other, forming a cylindrical structure. The cambium layer is present between these two tissues. Conjoint vascular bundles are typical of dicotyledonous plants.
Concentric vascular bundles, on the other hand, have xylem tissue surrounded by phloem tissue, forming a circular or oval shape. The cambium layer is present between the xylem and phloem tissues. Concentric vascular bundles are found in monocotyledonous plants.
In summary, the main difference between conjoint and concentric vascular bundles is the arrangement of the phloem and xylem tissues. Conjoint vascular bundles have phloem and xylem tissues arranged adjacent to each other, while concentric vascular bundles have xylem tissue surrounded by phloem tissue.
