Nymphaea macrosperma is an aquatic annual or perennial flowering plant in the family Nymphaeaceae. It is native to Australia and New Guinea.
Nymphaea macrosperma is an aquatic annual or rhizomatous herbaceous perennial, with rounded rhizomes that lack stolons. The glabrous, orbicular, elliptic or suborbicular leaves with a dentate margin are 17âÂÂ38 cm long, and 15âÂÂ31 cm wide. The abaxial leaf surface has a strong midrib and 6 palmately arranged primary veins, which are reticulate towards the leaf margin. The petioles are up to 2.5 m long, and 2-4 mm wide.
The 6âÂÂ7 cm wide, diurnal flowers extend above the water surface. The four oblong sepals with a rounded apex are 25-55 mm long, and 9-25 mm wide. The 10âÂÂ18(âÂÂ22) white, blue, or purple, oblanceolate to spathulate petals have an obtuse apex. There is a conspicuous gap between petals and stamens. The androecium consists of 150âÂÂ200 stamens. The gynoecium consists of 10âÂÂ13 carpels. The 4 cm wide fruit bears oblong to ovoid, hairy, 3âÂÂ4.5 mm long, and 2âÂÂ3 mm wide seeds.
It was published by Elmer Drew Merrill and Lily May Perry in 1942. In the same publication, the species was described a second time as Nymphaea dictyophlebia , which is a synonym of Nymphaea macrosperma .
The type specimen was collected by LJ Brass in Lake Daviumbu, New Guinea (British New Guinea) in August 1936.
It is placed in Nymphaea subgenus Anecphya.
The specific epithet macrosperma means large-seeded.
It occurs in up to 2.5 m deep stagnant or flowing water in lagoons, swamps, billabongs, and drainage channels on clay substrates. It can occur in slightly brackish water.
The NCA status of Nymphaea macrosperma is Special Least Concern (SL). Under the Biodiversity Conservation Act 2016, it is classified as Not threatened.
The plant is a traditional Aboriginal bushfood. The seeds are usually described as "sweet like a pea" and are eaten for lunch.