Green bean parenchyma cells and seed, SEM

Green bean pod parenchyma cells and seed (Phaseolus vulgaris; Blue Lake variety), coloured scanning electron micrograph (SEM). Shown here is a fresh cross section through a green string bean pod revealing a bean seed surrounded by parenchyma cell tissue. The been pod tissue is composed of inner and outer parenchyma cells. The outer parenchyma cells have large substomatal and intercellular spaces surrounded by a thick-wall hypodermis. Cells of the outer parenchyma contain numerous starch granules and are thicker walled than the inner parenchyma cells. The inner parenchyma cells are thin-walled and form a compact, succulent tissue with only small intercellular spaces. They contain some starch granules and they compose the inner bean pod tissue that surrounds the bean seeds. Magnification: x6 when shortest axis printed at 25 millimetres.