Periderm

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Periderm
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Periderm

• Phellogen cork cambium
• Phellem cork
• Phelloderm parenchyma like tissue

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Periderm, Cork, and Bark

• Bark all the tissues outside of the vascular
  cambium
• Inner Bark includes all the tissues from the
  secondary phloem outward to the phelloderm (or
  phellogen)
• Outer Bark includes the periderm and all the
  tissue outside of it
• Rhytidome
• all the successive periderms that develop
• bark external to the last formed periderm

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Periderm developing on a branch
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Development of Periderm
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Periclinal divisions of sub-epidermal cells leads
to the development of phellogen
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In Quercus alba, the phellogen originates in
sub-epidermal cells
Phellogen has produced 4 layers of phellem (cork)
and one layer of phelloderm
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In Solanum (nightshade), the phellogen arises
from the epidermis
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Phellogen in Clematis originates deep in stem
tissue from phloem parenchyma cells below the
fiber caps
Phellogen (cork cambium)
Vascular cambium
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In grape vines, the phellogen also originates in
the primary phloem
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Periderm with tannins
Clusia
Oak
Tannins deter insects and other animals from
feeding on bark, adding to the protective
capacity of bark.
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Tilia periderm
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Lenticels
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Lenticels in moonseed form prior to periderm
formation
Cuticle
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Lenticel in Aristolochia
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Sambucus lenticel
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Lenticel in ivy stem
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Rhytidome
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Robinia rhytidome
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Pine
Walnut
Paper birch
Crepe myrtle
Sweetgum
White ash
Tilia
White Oak
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Commercial cork is obtained from Quercus suber,
the cork oak tree
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Harvesting and Regrowth