the function of epidermis:

in the lower part there is the sign,cellula,membrua, sinkline, and midrib

in the upper part of epidermis there is also the sign cell, cellule, membrua, and sinotopilensicuaye

and in wax layer is the botany crispifiedencius "crispifiedencius" is a kind of cell which leaves layer the insects into it.

and the last layer is synocimprotocium membulare crisd.

Epidermis, in botany, outermost, protoderm-derived layer of cells covering the stem, root, leaf, flower, fruit, and seed parts of a plant. The epidermis and its waxy cuticle provide a protective barrier against mechanical injury, water loss, and infection.

The stoma, or pores of a plant control all gas exchange. The stoma is found in the epidermis of the leaf.

Hair is any of the numerous fine, usually cylindrical, keratinous filaments growing from the skin of humans and animals; a pilus.

In botany it is a filamentous outgrowth of the epidermis.

Answer:

the epidermis of a leaf includes: upper epidermis and lower epidermis but if you are referring to the epidermis of an onion: it is only one layer