In protosteles, it is in 
In protosteles, it is in the center of the stem, and in angiosperms, rays, fibers, and axial parenchyma cells make up one form of it. Its meta- type is distinguished by wider tracheids, and its most specialized structure is known as the trachea. Transpirational pull causes negative pressure to form in it, and it is used to transport water and minerals from the roots to the rest of the plant. FTP, the cambium separates what part of a plant's vascular system from the phloem.
In protosteles, it is in the center of the stem, and in angiosperms, rays, fibers, and axial parenchyma cells make up one form of it.
{xylem}