secondary growth is the increase in the girth of plant organs caused by the activity of lateral meristems, such as vascular cambium and cork-cambium . This process is characteristic of dicotyledonous plants and gymnosperms (which include conifers and cycads) . Conversely, monocotyledonous plants, such as grasses, do not undergo secondary growth . Therefore, grasses are the only plants listed that would exhibit little to no secondary growth.