Tilok pana or Floating fern, Salvinia natans
Tilok pana or Floating fern (Salvinia natans, family: Salviniaceae) is a aquatic herb which floates on water, 1-3 cm in length. Actually it is an annual water fern. The good-looking fern grows well in stagnant water with the support of humid air and wide daylight. It is found throughout the tropical regions of the world.
Other names: Ulki pana (Bang); Floating watermoss, Floating moss, Water butterfly wings (Eng).
It has two leaves, which float on the water. Another leaf that is half-floating acts as root. Its leaves have a special layer to keep the process of photosynthesis from excess sunlight and to prevent it from rotting in water.
As ferns reproduce through their spores, so does this plant.