Applies to cells that are living or dead at maturity (e.g., fiber cell or tracheid) and includes any external encapsulating structures (if present) such as the plasma membrane and the plant-type cell wall. Definition of cell GO:0005623: "The basic structural and functional unit of all organisms. Includes the plasma membrane and any external encapsulating structures such as the cell wall and cell envelope". GO:0009505. Definition of plant-type cell wall (GO:0009505): A more or less rigid structure lying outside the cell membrane of a cell and composed of cellulose and pectin and other organic and inorganic substances, synonym; exact: cellulose and pectin-containing cell wall.