The root system includes those parts of the plant below ground, such as the roots, tubers , and rhizomes . Dermal tissue covers the outer surface of herbaceous plants. Dermal tissue is composed of epidermal cells, closely packed cells that secrete a waxy cuticle that aids in the prevention of water loss. The ground tissue comprises the bulk of the primary plant body. Parenchyma, collenchyma, and sclerenchyma cells are common in the ground tissue.
Vascular tissue transports food, water, hormones and minerals within the plant.
Vascular tissue includes xylem, phloem, parenchyma, and cambium cells. Two views of the structure of the root and root meristem. Images from W.H. Freeman and Sinauer Associates, used by permission. Plant cell types rise by mitosis from a meristem . A meristem may be defined as a region of localized mitosis.