Differences Between Secondary Growth in Dicot Stem and Root

Beyond the wavy-versus-circular difference in how the cambial ring first appears, dicot stem and dicot root secondary growth differ in several other, related ways, summarised in the table below. Because the stem's cambial ring is partly primary (fascicular) and partly secondary (interfascicular) in origin, it starts out circular from the very beginning, whereas the root's completely secondary cambial ring starts wavy and only becomes circular afterward. The periderm also originates differently in each organ: generally from the cortical cells in the stem (an extrastelar origin, outside the stele) but generally from the pericycle in the root (an intrastelar origin, inside the stele). Because a stem is exposed aboveground while a root is buried underground, a stem generally produces more cork t …