Tracheids are dead cells and like sclerenchyma has neither the nucleus nor the phrotoplast. The lumin of cell is large. The wall of the tracheids is provided with a number of bordered pits. Taracheids have oblique end walls. They help in conduction and mechanical support.

Vessles arise from traicheids through the desolution of end walls. Vessels are composed of rose of cells placed one above the other with the transverse walls being eliminated.