Stems

Stem Functions:

• Support of Leaf Display
• Support of Flower Display
• Support of Fruit Display
• Conduct water and minerals up from soil
• Conduct water and nutrients (sugar, amino acids) from leaf to rest of plant
• Photosynthesis (in some plants, eg. cacti)
• Storage of water, etc (cacti, underground stems (potato), swollen bases kohlrabi)
• Anchorage especially in vines
  twining (morning glory)
  adventitious roots (poison ivy)
  "suction cups" (Virginia creeper)
• Protection from fire, herbivory Sequoia bark
  Prickles, Spines, Thorns
  Chemical Defenses glands (see later)

Stem Structure/Function:

• Epidermis - prevents water loss with cuticle (maybe gas exchange & window for PS)
• Cortex
  • Collenchyma - plastic support during growth
  • Parenchyma - storage (maybe PS)
• Vascular Bundle
  • Bundle Cap Fibers - elastic support after growth
  • Phloem - conducts nutrients away from leaves
  • Cambium - makes secondary wood by mitosis
  • Xylem - conducts water & minerals up from roots
• Pith - storage (esp water)

Go back to the Course Schedule.