Vascular land plants make lignin, a polymer used to strengthen the secondary cell walls of xylem tracheids and vessels to keep them from collapsing when a plant sucks water through them under water stress.
Ihishkan n akal chund lignin, polymer exdaman i aassuhi n iɣalayan win issin n xylem tracheids d vessels i a tan ogazan daɣ egadal alwaq wa id iswa ahishk aman sarsan daw aman