Here is a reply from Shrikant ji:
"Dear Mr. Garg,
This plant grows only when the level of flowing water recedes and the flow of water becomes low but not stagnant. This is typical plant of the paddy fields, hence it is called as Bhat(rice)-Kamal in marathi. You may observe that the submerged leaves are narrow and shortly petioled and the floating leaves are with long spongy grooved petioles; their length varying as per the level of water. The spathe in which the flower grows is also with varying length of grooved tubular spongy peduncle to bring the flower just above the water. regards
Shrikant Ingalhalikar "