an elongated cell , the contents of which are non-living
TRAY-kee-idz Less specialized conducting cells in plants that are elongated, dead at maturity, and have thick walls. 538
Long, tapered cells with pitted walls that form a system of tubes in the xylem and carry water and solutes from the roots to the rest of the plant. One type of xylem cells. Tracheids are long and relatively narrow, and transport materials from the roots upward. Tracheids are dead at maturity and have lignin in their secondary walls. PICTURE 1 | PICTURE 2
water-conducting tissues in the xylem.