bio

Xylem

The system of microscopic pipes in a tree's wood that carries water and minerals up from the roots to the leaves. The xylem is the "straw" the whole tree drinks through: water is pulled up it as an unbroken column by cohesion-tension. The width of these pipes, and the friction as water grinds through them, is part of why getting water to the crown gets harder the taller a tree grows.