The root hairs are the principal absorbing organs, water is drawn into the root hair mainly by osmosis across the cellulose cell wall and the semi-permeable protoplast into the vacuole. The osmotic uptake is aided by active transport. From the root hair water passes to the vascular tissue in the center of the root through parenchyma cells by three possible mechanisms; Through sap cytoplasm by diffusion from cell to cell via plasmodesmata, along and betwern the cell walls by diffusion through intercellular spaces.
Water passes from the parenchyma cells into the vascular tissue of the root due to upward gradient created by transpiration pull from leaves. Transpiration pull is maintained by evapouration water from leaf surface. Water in root vascullar tissues now move to stem aided by sew mechanisms. Transpiration pull still operates here aided by root pressure, which pumps water upward.
Forces of adhesion between walls of vascular tissue and molecules as well as force of cohesion between water molecules. These force collectively move water up the stem to the vascular tissues of leaves. From leaf xylem, water diffuses into mesophyl cell to intercellular spaces and then to sub-stomata cavities then leaves the leaf in form of water vapor through the stomata