Epidermis (plant)
The epidermis (from the Greek ἐπί , epi , “over”, “on top” and δέρμα, derma , “ skin ”) is a primary terminating tissue of the stem and leaves in higher plants . The main task of the epidermis is to protect the underlying plant tissue. The epidermis usually consists of just one layer of cells with a particularly thick outer wall. It also has a layer of wax, the cuticle , resting on the epidermal cells . With some plants, such as conifers , there may also be tertiary wall thickening.
As a result of the secondary growth in thickness of the plant, the epidermis can be destroyed and replaced by secondary closing tissue. The rhizodermis of the root is generally not considered an epidermis because it is endogenous and does not have a cuticle.
Epidermal cells are usually free of chloroplasts , but other plastids can certainly occur. However, chloroplasts are found in the guard cells of the stomata and in the epidermal cells of ferns and some shade plants .
literature
- Andreas Bresinsky , Christian Körner , Joachim W. Kadereit , Gunther Neuhaus , Uwe Sonnewald : Strasburger - textbook of botany. 36th edition. Founded by E. Strasburger. Spectrum Akademischer Verlag, Heidelberg 2008, ISBN 978-3-8274-1455-7 .