Hydrophytes

• examples

  • water lillies (surface)
  • water cress (surface)
  • duckweeds (submerged or free-floating)
  • yellow iris (edges)
• very thin/no waxy cuticle


  no conservation of water necessary

  • always readily available
• many stomata (always open)


  maximising gas exchange

  • in floating plants, stomata need to be on upper side of plants as to not be submerged into water, where gas ex cannot occur
• reduced structure


  water supports leaves and flowers
• wide flat leaves


  to capture maximum amount of light possible
• small roots


  less need for water uptake, as can diffuse through stem easily
• large SA of stems and roots under water


  maximises area for photosynthesis and oxygen to diffuse
• air sacs


  enable leaves/flowers to float
• aerenchyma 


  • specialised parenchyma tissue
  • many large air spaces
  • buoyancy
  • low resistance pathway for movement of substances to submerged tissues