fozzyb- From your pictures esp the one with the white flowers,, I also think you have a plant in the arrowhead genus: Sagittaria. FYI: S. lancifolia typically does not grow in MI, but S. latifolia is common in MI. I am not sure of the species unless I can see a better, close-up photo of leaves, flowers or individual seeds. MI has 6 different species of arrowhead and since the leaves can be variable shaped most taxonomic keys use the flowers and seed shape as separating characters. Since your pictures did not show leaves from a mature flowering plant the other possible name is "water plantain" (Alisma spp.) which can be easily confused with some arrowheads.
