Nymphaea gigantea

Giant Waterlily

Description

Nymphaea gigantea is a beautiful waterlily has large (to 25 cm) blue-white flowers that emerge from the water. Leaves circular with a radial slit, to 75 cm diam., margins toothed with acute, regularly-spaced teeth to c. 5 mm long. The plant is a perennial and grows from small tubers. The large circular leaves grow up to 75 cm in diameter and have toothed margins. Flowers emergent, to 25 cm diam. and standing to 50 c. above the water surface. Sepals 4, green with a bluish tinge on the margins. Petals usually lilac-blue when young, gradually fading to light blue, almost white.
The Giant Waterlily is found in permanent water with deep mud in tropical and subtropical Australia. It occurs on the northern coast of NSW and up through Queensland.

Reference
http://www.rbgsyd.nsw.gov.au/education/Resources/bush_foods/Nymphaea_gigantea