Leaf

• Leaves

  Lateral out growths that develop from the  node of the stem

  Main photosynthetic organ of the plant
• Parts of a leaf

  Petiole

  Blade / lamina

  Stipules

  Midrib

  Veins
• Leaf Structure

  A) simple

  B) palmately compound

  C) ternate (trifoliate)

  
• Leaf Structure

  A) pinnately compound

  B) bipinnate

  C) tripinnate

  
• Laminar Shape

  A) elliptic

  B) obovate

  C) ovate

  D) oblong

  
• Laminar Symmetry

  A) symmetrical

  B) asy

  C) base asymmetrical

  
• Base Shape

  A) cuneate (straight)

  B) convex

  C) rounded

  D) truncate

  E) concave

  F) concavo-convex

  
• Base Shape

  A) decurrent

  B) complex

  
• Base Shape

  A) cordate

  B) lobate

  C) sagittate

  D) hastate

  
• Apex Shape

  A) straight

  B) convex

  C) rounded

  D) truncate

  E) acuminate

  F) complex

  
• Leaf Margin

  A) dentate

  B) serrate

  C) crenate

  D) entire

  E) revolute

  F) erose

  
• Phyllotaxy - Arrangement of leaves along the stem.

  General Types:

  • Alternate/Spiral - only one leaf develops at each node.
  • Opposite - two leaves opposite each other at each node.
  • Whorled - three or more leaves develop equidistantly around the node.
  • Decussate - each leaf attached at 90 degrees from those above and below.
  • Fasciculate - two or more leaves develop at only one side of the node.
• Phyllotaxy

  A) alternate

  B) opposite

  
• Phyllotaxy

  A) whorled

  B) decussate

  
• Leaf Modifications

  • Phyllode - consist of flattened blade-like petiole
  • Tendrils - coiled and twinning leaf or leaf part; usually a modified leaflet
  • Spines (stipular, petiole, leaf) - a sharp-pointed leaf or leaf part
  • Storage leaves - modified to store water
• Carnivorous leaves:

  • Pitcher leaves - shaped like a container, which bears an internal fluid and functions in the capture and digestion of small animals.
  • Tentacular leaves - bears numerous, sticky, glandular hairs or bristles that function in capturing and digesting small animals;
  • Trap leaves - mechanically move after being triggered, in the process capturing and digesting small animals.
• Leaf Modifications

  A) phyllode

  B) vestigial rachillae

  C) leaf tendril

  D) stipular spines

  E) petiole

  F) petiole spine

  G) leaf spines

  
• Carnivorous Leaves

  A) pitcher leaves

  B) tentacular leaves

  C) trap leaves

  D) bract

  E) ower

  
• Parts of a Leaf

  A) blade

  B) midrib

  C) secondary veins

  D) bud

  E) petiole

  F) stipules