The fruit of Nymphaea is spongy berry, which dehisces by the swelling of mucilage surrounding the seeds. The seeds thus set free float as spongy aril entangles air bubbles. They settle down to the bottom of pond as aril decays.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.