PHOTO STUDY 5-1 Pelargonium (geranium): Stem with secondary cortex, t.s.

View the tissue outside the primary cortex. Is there an epidermal layer? That tissue immediately under the epidermis is phellem (cork). See that its constituent cells are without protoplasm: they are mere walls, though some waste productsmay have accumulated in them. Note also that these cells are lined up in regular, radial rows. At the inner boundary of the cork tissue, recognize a single layer of living, nucleated cells, the phellogen or cork cambium. Between the latter and the tissue internally (cortex) is a thin layer of phelloderm. Both cork and phelloderm have been produced by the phellogen How can you recognize the boundary between cortex and phelloderm? What features of cork tissue are of protective significance? Do you judge cork to be more efficient than epidermis, or less so?