By the transpiration stream, in the xylem.The xylem is the tube in the plant in which water and solutes are transported from the plant roots to the stem and leaves. The xylem allows capillary action, which causes a continuous column of water, called the transpiration stream or the transpiration pull. As water evaporates (transpires) from the pores on the leaf's surface, more water is drawn up from the roots to create this continuous column.