I saw a couple in habitat, probably U. juncea, or possibly cornuta. The plants I saw flowering were in full direct sun, but they had very few leaves, and I could only find two of them (on ground that I think is flooded parts of the year). They cleary were having trouble competing with D. rotundifolia under those conditions.
Has anyone else seen any of these plants in habitat? I kept looking for them all summer, and I must have found around 15 aquatic utric ponds, and at least four species of aquatics, but only those 2 terrestrials.