Epidermis-1 

The Epidermis is the interface between the plant and its environment. Consequently, many adaptations have evolved to foster existence in terrestrial ecosystems. 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.

Sectional view of a typical
Epidermal cell showing the Cuticle and Stomata with Guard Cells.

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.