Tracheids are unicellular and with wide lumen

Tracheids are multicellular and with narrow lumen

Vessels are multicellular and with wide lumen

Vessels are unicellular and with narrow lumen

Excretory material

Reserved material

Insect attracting material

Wastes

Formation of procambium, primary phloem and xylem simultaneousl

Differentiation of procambium followed by the formation of secondary xylem

Differentiation of procambium, formation of primary phloem followed by formation of primary xylem

Differentiation of procambium followed by the formation of primary phloem and xylem simultaneously