Hydrophytes and Xerophytes

• Xerophytes


  Plants adapted to dry and arid conditions
• Xerophytes


  • Physiological and structural (xeromorphic) adaptations to maximise water conservation
• Transpiration rate


  1. Moves water potential gradient

  2. Causes the rate of transpiration
• Xerophytic adaptations


  • Fleshy codes
  • Leaves reduce surface area
  • Leaves rolled or folded when flaccid
  • Sunken stomata
  • Stomata closed during light, open in dark (CAM plants)
  • Thick waxy cuticle
• Hydrophytes


  Plants adapted to living in freshwater
• Hydrophytes


  • Excess water uptake not a major concern
  • Little need for water transport mechanisms or adaptations that reduce water loss
  • Main challenge is receiving enough carbon dioxide during the day and enough oxygen during the night
• Hydrophytic adaptations


  • Floating leaves
  • Thin waterproof waxy cuticle
  • Stomata located on upper leaf surface
  • Reduced root system
  • Reduced veins in leaves
• A common hydrophyte is the waterlily