Compared Seasonal growth cycles proceed from seed germination, to seed formation, to death. Growth at Lateral Meristems Vascular cambium is a cylinderlike lateral meristem. It produces secondary xylem on its inner face and secondary phloem on its outer. In regions with cool winters or dry spells, the vascular cambium is inactive during part of the year. Late wood contains xylem with small diameters and thick walls.
Tree rings appear as alternating light bands of early wood and dark bands of late wood.