The yellow-fringed water snowflake (Nymphoides geminata) is one of quite a number of tropical and subtropical species in this genus. Nymphoides means "like Nymphaea", like waterlilies, and while sort of like waterlilies in the growth pattern of some species, they are not closely related at all. For small, shallow water gardens these can be quite nice, easy to grow, showy plants, and while growing this plant for reasons now forgotten the Phactor noticed the fringed petals. Now anything that increases the size of a floral display is generally interpreted as enhancing its ability to get visited and pollinated, and this was how the function of the fringe was explained. Quite by accident, the ever observant Phactor discovered that the fringe had a second function. Experimentation demonstrated that the fringe interacts with the surface tension of water, the same principle that allows a water strider to walk on water, and rather than rising water drowning the tethered flowers, it closes the petals, and when the water level recedes the flower reopens undampened, a useful adaptation for a plant growing in shallow water subject to rapid and brief changes in water levels. That was some real "fringe science", but without question it's a fabulous flower.