The giant waterlily has a rhizomatous growth habit - that is, the main stem of the plant grows horizontally under the ground (in this case in the mud at the bottom of a lake or pond) and only the leaves and flowers are seen above the surface.

[8] Nymphaea gigantea was first described in 1852 by the English botanist and illustrator William Jackson Hooker in The Botanical Magazine, based on material collected by John Carne Bidwill from the Wide Bay area of Queensland (at that time still a part of the colony of New South Wales).

[1][16] As of 6 July 2023[update], this species has not been assessed by the International Union for Conservation of Nature (IUCN).

The species was brought to England by Frederick Strange, where it received notices in newspapers and began to be cultivated by nurseries.

[13][15]: 226  The golfball-sized tubers were collected from the muddy bottoms of water bodies by indigenous women and roasted before eating.