Water travels up a tree through small tubes called xylem. Aswater is released through the leaves of the tree, it creates anegative pressure at the top of the tree. Even though the weight ofall the water is dragging it down via gravity, the adhesion andcohesion properties of water create a strong attraction between thewater molecules. Another property that helps is capillary action,where the water molecules are more strongly attracted to the wallsof the xylem than they are to each other. The height that capillaryaction can draw water is inversely proportional to the width of thetube, which means that the xylem and stomata can draw water up andincredible distance.