Epidermis-1

Lecture Directory	Sclerenchyma-1	Anatomy Home Page	Next Page
Epidermis-1
The Epidermis is the interface between the plant and its environment. Consequently, many adaptations have evolved to foster existence in terrestrial ecosystems where the leaves are exposed to the atmosphere. The "Conquest of the Land" is really the "Conquest of the Atmosphere" There are four important structures in this image. A= Typical Epidermal cell with wavy walls; B=Guard Cells; C= stalk of Secretory Trichome; D=Secretory Cells of the Trichome.

Agave (Spanish Bayonet) This is a plant which lives in dry (Xeric) ecosystems. Its epidermis contains several important adaptations.
The leaves can be highly reflective due to Epidermal Wax and Cuticle. This reflects excess sunlight which can damage leaves.
Agave Epidermis stained with Toluidine Blue - Locate the Cuticle, the Stomata & the Guard Cells.
*Surface view of Agave* epidermis - Epidermal cells can have rectangular shapes as seen here or wildly undulating shapes.**
Agave epidermal cells viewed with polarized light. These cells contain Silica Bodies in their vacuoles. These are birefringent. I think these may be involved in light scattering and the quantity of light available for photosynthesis.

*The Ice Plant (Mesembryanthemum) has shiny Leaves. This is due to Swollen Epidermal Cells that Store Water.*


Zebrina Leaves are very shiny. The upper surface has a silver sheen. This is due to bulbous Epidermal Cells that reflect Light. Similar cells are found on the Lower Epidermis but it is harder to photograph.
*Epidermal Cells may have complex shapes. This is illustrated by Replicas of Arabidopsis* Leaves seen to the right and in the two cells below**		*Adaxial (upper) Surface Replica of Arabidopsis* leaf: Low Magnification**
*Adaxial (upper) Surface Replica of Arabidopsis* leaf: High Magnification**		*Adaxial (upper) Surface Replica of Arabidopsis* leaf: False color produced by crossed polarizers.**