Angiosperm Leaf: Stomatal Pits In Nymphaea - Cross Section: Nymphea Leaf Common Name: Waterlily Magnification: 400x Both The Upper (adaxial) And Lower (abaxial) Epidermis Are Uniseriate And Contain Chloroplasts. The Air Exposed Adaxial Epidermis Is Well Cutinized And Contain Numerous Stomata That Open Into Large Substomatal Air Chambers. The Submerged Abaxial Epidermis Has A Very Thin Cuticle And Lacks Stomata. Dark Staining Slime Glands Are Present On The Abaxial Surface. Deep To The Upper Epidermis Are Several Layers Of Tightly Packed Palisade Mesophyll, The Chief Photosynthetic Tissue Of The Leaf. Most Of The Leaf Interior Is Occupied By A Deeper Zone Of Spongy Mesophyll With Large Air Spaces. Large Red Staining Branched Astroscleroids Are Abundant Throughout The Mesophyll. Photo