Leaf Parts and Function

Lower epidermis

Outmost tissue on the lower side of the leaf; protects the leaf

Upper epidermis

Outmost tissue on the upper side of the leaf; protects the leaf

Palisade layer

Rows of elongated cells in the upper center of leaf; site of photosynthesis

Cuticle

Waxy layer on the covering of the epidermis; holds in moisture, prevents too much absorption of water

Stoma

Opening between the guard cells; allows for gas exchange and some water

Guard cells

Surround the stoma; control the opening and closing of the stoma

Vein

Supply support for the leaf; contain the xylem and phloem

Spongy layer

Irregular shaped cells in the lower center of the leaf; absorbs gas and some water

Air space

Space in the spongy layer; contain gases

Xylem

Found in the vein; transports minerals and water from roots to shoots

Phloem

Found in the vein; transports sugar and other products of photosynthesis from leaves to other parts of the plant

Chloroplast

Cells in the leaves that contain chlorophyll; trap light energy and convert it to chemical energy

Mesophyll

All of the middle tissue of the leaf