Descriptor : superficial protective layer (sub-epidermal)
Descriptor type : categorical
This descriptor concerns the organisation of the protective layer (sort of bark) of the stem.
Etagen meristem of the cortical ground parenchyma: a zone of cell divisions without permanent initials.
Some palms could conserve the initial epidermis (permanent epidermis) with stomata and in rare cases with epidermal hair. For other palms, the epidermis is no longer visible and a zone of more or less suberified parenchyma replaces it.
permanent epidermis
developed etagen meristem
suberization of ground parenchyma
- permanent epidermis
-
permanent epidermis
permanent epidermis
- developed etagen meristem (alignment of more than 10 cells)
-
a zone of cell division without permanent initial
[Philipp(1923)] M. Philipp. Über die verkorkten Abschlußgewebe der Monokotylen. Bibl. Bot. Stuttgart, 92(1-27), 1923.
anticlinal division of the parenchyma cells in the subepidermal zone
etagen meristem of the outer ground parenchyma
- suberization and sclerosis of the existing ground parenchyma
-
in some case a tangential alignement is slightly developed, but < 10 cells
suberization and sclerosis of the existing ground parenchyma
Hierarchy
identification within "subfamily" or "tribe" | |_ superficial protective layer (sub-epidermal) | |_ multicellular epidermal hair {developed etagen meristem (alignment of more than 10 cells) , suberization and sclerosis of the existing ground parenchyma} | |_ epidermal cells {developed etagen meristem (alignment of more than 10 cells) , suberization and sclerosis of the existing ground parenchyma}