Mostly on wet muds or very shallow (,5 cm) water, stranded by slowly falling water levels.
Previously recorded from this lagoon but without considering heterostyly. I checked 14 flowers in the wetland formed by lagoon overflow for heterostyly (a key character for Nymphoides montana) and found 8 S-morph (stigma below anthers) and 6 L-morph (stigmas above anthers), demonstrating heterostyly an confirming this as Nymphoides montana.