It's incredible to see how many different floating leaved plants we have in our freshwater lakes. Watershield (Brasenia schreberi) is one of the less showy ones:
The flowers on these plants only last for 2 days, so I was lucky to see some on my most recent expedition. The flower buds form underwater. When they come to the surface, only the female parts of the flower open on the first day, then it retracts and goes back under the surface for the night. On the second day the flower re-emerges, sporting only the male parts of the flower - this is an elaborate ruse to ensure cross-pollination! My pics show the second day of flowering.
The U.S. Forest Service website had this interesting tidbit about these overlooked little gems: "Watershield plants secrete a number of chemicals that kill or inhibit growth of a wide range of bacteria, algae, and other plants." Fascinating!
They can cover huge areas of the water surface, making it difficult to pass through in a kayak.