Tracheids Pits Vessel Elements Xylem Cells Diagram. They are responsible for the characteristic odor of wood. It is a type of conductive cell called a tracheary element.
At maturity the cells are no longer alive and the mature cells are devoid of protoplast. Tracheids have thick secondary cell walls and are tapered at the ends. Tracheary cells ie tracheids and vessel elements in xylem are a model system for cell differentiation.
Bordered pits are cavities in the lignified cell walls of xylem conduits vessels and tracheids that are essential components in the water transport system of higher plants.
The cells are non living at their maturity. Elongate tube like cell tapering rounded or oval ends hard lignified walls. They are very long tubule structures formed by the fusion of several cells end to end in a row vessel elements are shorter and wider than tracheids. They are dead cellswater and minerals move upwards through vessels and tracheids.