As the water gets deeper, the wavelength of light gets shorter until its gone. Organs specialized to excrete salts -selectively remove certain ions from the vascular tissus of the leaf. Its three leaves and anthers form a sailboat. The spathe floats along until hopefully it bumps into a stigma. A chinese lotus can lay dormant for over 1,000 years.
Algal blooms can block the sunlight and nutrients to submerged plants.
Lacunae alsohave a structural role. An experiment was done to demonstrate the oxygen gradient in plants. The oxygen istaken in from the air by photosynthesis and travels through the plant and out the root hairs. When low oxygen levels are present, plants use other mechanisms to adjustfor respiration. Aquatic plants can respire anaerobically.