Descripteur : superficial protective layer (sub-epidermal)

Type du descripteur : 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.

../images/Pseudophoenix_sargentii.jpg

permanent epidermis

../images/Syagrus_sancoana_copie.jpg

developed etagen meristem

../images/Phoenix_dactylifera_epi_1.jpg

suberization of ground parenchyma


permanent epidermis

../images/Pseudophoenix_sargentii.jpg

permanent epidermis

../images/Caryota_rumphiana.jpg

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

../images/Syagrus_sancoana_copie.jpg

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

../images/Phoenix_dactylifera_epi_1.jpg

suberization and sclerosis of the existing ground parenchyma


Hiérarchie

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}

Fait partie des groupes