Easily confused with : Fringed Water-Lily but Fringed Water-Lily has much smaller leaves, and a paper-thin fraying petals, whereas yellow water lily has much larger leaves and much thicker yellow petals.

Uniquely identifiable characteristics : It is called Brandy Bottle because the flowers smell of brandy, and at the fruit stage in the development look similar to bottles. The reason why the flowers smell of alcohol has to do with the anoxic conditions in a lake in which it is growing: without oxygen the sugars in the roots cannot be converted to energy and carbon dioxide via the normal metabolic process for plants, and have to proceed via a highly in-efficient alternative synthesis where it is converted to alcohol, as does yeast. But alcohol is poisonous to most species, and must be disposed of: In Yellow Water-Lily it is evaporated out of the yellow flowers whereas in beer and wine the alcohol cannot evaporate and slowly kills off the yeast as the percentage alcohol increases.

That said, another source tells that

Distinguishing Feature : Large leaves floating on still fresh-water. The flowers are much smaller than white water-lily and yellow, shaped like cups.

No relation to : Fringed Water-Lily [a plant with similar name] which is also yellow but is not a Water-Lily and instead belongs to the Bogbean Family.

This plant will yield a black dye.

QUINOLIZIDNE ALKALOIDS Yellow Water-Lily contains the poisonous alkaloids Nupharine, Nupharidine, Desoxynupharidine and some other quinolizidine alkaloids such as Nuphacristine and Nupharolidine. Quite a few also contain sulfur, such as Thionupharidine. These alkaloids are mostly contained in the rhizomes. Compare these quinolizidine alkaloids with Lupinine, a simpler Quinolizidine alkaloid.