The upper epidermis layer contains cells that are transparent allowing light to pass through to underlying cells.

Epidermis Plant Cell
Epidermis Plant Cell TutorVista.com Mostly text with a small illustration.
http://www.tutorvista.com/biology/epidermis-plant-...
Leaf
Leaf Wikipedia.org Article with several good images.
http://en.wikipedia.org/wiki/Leaf
Plant Structures: Leaf
Plant Structures: Leaf SparkNotes.com Leaves contain chlorophyll and are the sites of photosynthesis in plants. Their broad, flattened surfaces gather energy from sunlight while apertures on the t
http://www.sparknotes.com/biology/plants/plantstru...
The epidermis
The epidermis, Glogster Unspecialized cells, hairs that grow under the leaf, and wax coating - all presented via an illustration.
http://www.glogster.com/lifetereal/the-epidermis/g...
What is the function of upper epidermis in a leaf?
What is the function of upper epidermis in a leaf? Wikianswers.com Clear, concise answer; scroll down to view related questions.
http://wiki.answers.com/Q/What_is_the_function_of_...