LEAF ANATOMY

• Leaves of plants that live in moderate environments; typical leaf anatomy is described using these.

  Mesophytic Leaves
• The outer layer of cells covering the leaf, providing protection.

  Epidermis
• Openings in the epidermis that allow gas exchange.

  Stomata
• Cells that regulate the opening and closing of stomata.

  Guard Cells
• Layer of cells under the epidermis, rich in chloroplasts, where most photosynthesis occurs.

  Palisade Mesophyll
• Loosely packed cells below the palisade layer that aid in gas exchange.

  Spongy Mesophyll
• Xylem and phloem that transport water, nutrients, and sugars.

  Vascular Tissues
• Leaves adapted to aquatic environments.

  Hydrophytic Leaves
• Air spaces in leaves that help them float and exchange gases in water.

  Aerenchyma
• Star-shaped cells that provide structural support in hydrophytic leaves.

  Astrosclereids
• Leaves adapted to dry environments; have features to minimize water loss.

  Xerophytic Leaves
• There are two bundles of vascular tissue embedded within a region of cells called?

  transfusion tissue
• The transfusion tissue and vascular bundles are surrounded by a distinct layer of cells called the

  Endodermis
• There are several canals that appear as large, open circles in the cross section of the leaf.

  Resin canals
• The stomata are located at the base of these pockets, called _____?

  stomatal crypts
• A waxy layer covering the epidermis that prevents water loss.

  Cuticle
• Cells that allow leaves to alter their surface area to minimize water loss during dry conditions.

  Bulliform cells
• A distinct layer of cells around the vascular tissue, similar to that in roots.

  Endodermis