Vascular Leaves

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Vascular Leaves

• D.L. Mowery
• Douglass High School

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Leaf Function

• Photosynthetic organ of a plant usually they are
  composed of 2 parts the blade and petiole
• Main site of evaporation of water from the plant
• Gas exchange carbon dioxide for photosynthesis
  and oxygen from photosynthesis and for
  respiration are usually exchanged through the
  leaves

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Parts of a Typical Leaf
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Function of Leaf Tissues

• Cuticle waxy covering which prevents water loss
• Upper and Lower Epidermis - Protection
• Palisade Mesophyll Cells main photosynthetic
  tissue
• Bundle Sheath Cells - primarily function for
  rigidity and protection
• Xylem transports water
• Phloem transports sugars
• Spongy Mesophyll Cells create spaces for gas
  exchange
• Guard Cells regulate the flow of water
• Stomata openings in the leaf, allow the
  exchange of gases
• Vein (Vascular bundle) transportation of water
  and sugars
• Sclerenchyma strength and support

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Most photosynthesis takes place in the palisade
cells
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Stomata

• Pores" in leaves (and stems) through which CO2
  is taken in and O2 is released during
  photosynthesis. Plants control when stomata are
  open or closed and the width of the opening
  (formed by two guard cells that expand and
  contract to open and close the space between them)

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Leaf Types
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Leaf Margins
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Leaf Arrangements
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The End.