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Monocot Stem
Primary Growth
The vascular bundles are randomly scattered in the ground tissue (usually comprised of parenchyma cells). Each vascular bundle is surrounded by a bundle sheath and contains xylem orientated towards the inside and phloem towards the outside of the stem. The outer layer is epidermis.
Monocot, Dicot or Gymnosperm Root
Primary Growth
Root anatomy is virtually the same for monocots, dicots and gymnosperms. The vascular tissue occurs in the center, which is surrounded by two rings of cells, the pericycle and endodermis, then the cortex and epidermis. The cell walls of the endodermis that are perpendicular to the root surface (i.e. the radial and anticlinal walls) are sealed by a suberized band called the Casparian strip.  Root hairs are extensions of the epidermal cells.
Woody Dicot or Gymnosperm Root - Secondary Growth
A woody dicot or gymnosperm root in secondary growth looks almost identical to a stem in secondary growth. Therefore, see Stem Cross Section - Woody Dicot or Gymnosperm - Secondary Growth. The only difference is that the woody root has remnants of the xylem in the center as opposed to pith.