As the water is drawn through tubes called xylem vessels, the tension increases until it becomes too great and the supply is cut off, limiting the tree height.
وفيما يصعد الماء عبر انابيب نسيج الخشب ،‏ يزداد وزنه كثيرا بحيث تزداد عملية صعوده صعوبة .‏