Nymphaea odorata subsp. odorata is found in most North American states and provinces, though its presence in western North America is by way of introduction (see Non-native Invasive Freshwater Plants — Fragrant Water Lily from the Washington Department of Ecology). It is also found in Mexico, Central America and the West Indies (and naturalized in parts of South America).
Various vernacular names are used for this taxon, but as odorata means “fragrant” or “scented”, my preference is fragrant water lily. However, American white water lily and variations thereof are also common.
Several adaptations are required for plants to survive in an aquatic environment. For water lily, these include having stomata (pores for gas exchange) solely on the upper leaf surface (in most dryland plants, stomata are concentrated on the lower leaf surface) and air chambers running the length of the stem to deliver oxygen to the plant’s rhizomes (more photos of Nymphaea odorata, including rhizomes). Interestingly, stomata in the related Nymphaea lutea have lost the ability to regulate the size of the opening for gas exchange and instead remain permanently open (and presumably this is the case for Nymphaea odorata as well). This is unsurprising, though, as water loss through gas exchange pores is not a concern for aquatic plants.