White water-lily  (Nymphaea alba)

White water-lily flowers are produced between June and September (6); they are visited by bees, flies and beetles, but it seems that they are often self-pollinated (2). There is much variation in the size of both the leaves and the flowers; certain populations in nutrient-poor waters are much smaller than average (2). These differences seem to have some genetic basis, as even when moved to nutrient-rich waters the plants stay small for a number of years (2).