•RADIAL: Xylem and phloem are alternate with each other separated by parenchymatous cells.
•CONJOINT: Xylem and phloem in the same radius.
•COLLATERAL: Phloem lies towards outerside and xylem towards innerside.
•BICOLLATERAL : Phloem lie on outer and inner side and xylem sandwitch between them.
•CONCENTRIC: One tissue surrounds the other it is of two types:
•AMPHIVASAL : Phloem lies in the centre xylem surrounds it.
•AMPHICRIBAL: Xylem lies in the centre phloem surrounds it.
•EXARCH: Protoxylem towards periphery metaxylem towards centre.
•ENDARCH: Metaxylem towards periphery protoxylem towards centre. MESARCH: Protoxylem remain surrounded by metaxylem
