Vasular tissue is the tissue concerned with the transportation/tranlocation in all vascular plants. It’s mainly organised by vascular bundles, the vascular bundles are continuous from roots to stem to leaves.
In angiosperm, vascular tissue is made up of xylem and phloem. Xylem tissue is mainly responsible for movement of water and mineral salt in solution while the phloem is concerned with the translocation of organic substace. Xylem contain two type of conducting element; vessels and tracheids.
Vessels are formed from chain of elongated cells placed end to end, they possess large lumen which ensure communication between vessels. Vessels are identified dead cells/without protoplasm with lignified walls perforated with numerous pits, pits may be bordered with or without holes, and the walls may have spiral or annular thickenings.
Tracheids are similar to vessels, except that they are polygonal/five-sided in cross section, they possess tapering end walls perforated by pits.
Phloem tissue consist mainly of elongated sieve elements placed end to end to form sieve tubes. Sieved tubes run parallel with the long axis of the plant, it’s derived from cells without nuclei; it possess end wall called sieve plates. Sieve plate is perforated with numerous pores, the sieve elements filled with cytoplasmic filaments.