phloem

noun

(Gr. phloios: [inner] bark) A complex plant tissue specialized to transport synthesized foods, mainly sugars (carbohydrates), in a vascular plant. It is composed of sieve elements, parenchyma cells and sometimes also of fibers and sclereids. It consists then principally of tubelike cells that lack nuclei, the end of one cell being linked to the next by means of a porous wall (sieve plate). The cells are controlled by small neighbouring cells, known as companion cells.