tracheid

noun

(L. trachia: windpipe, trachea; eidô: to look like) A type of cell occurring within the xylem of conifers, ferns, and related plants. Tracheids are elongated, slender, tapered at the ends, and their walls are usually extensively thickened by deposits of lignin. Water flows from one tracheid to another through unthickened regions (pits) in the cell walls.