Nymphaea immutabilis

Nymphaea immutabilis is a species of waterlily native to Western Australia, the Northern Territory, and Queensland, Australia.

Vegetative characteristics
Nymphaea immutabilis is an annual or perennial plant with globose rhizomes. The round, 70 cm wide leaves have dentate margins.

Generative characteristics
The flowers extend up to 50 cm above the water surface. The flowers have four sepals, and 34 petals. The androecium consists of 400 stamens. The gynoecium consists of 9-20 carpels. The globose, 5 cm wide fruit bears numerous 4 mm long, and 2.5 mm wide, rounded seeds with trichomes arranged in irregular rows. Immature seeds are red, but mature to brownish-grey seeds. The seeds have a mechanism of physiological dormancy.

Cytology
The chromosome count is n = 42. The genome size is 1408.32 Mb.

Generative reproduction
Flowering occurs from March to November.

Publication
It was first described by Surrey Wilfrid Laurance Jacobs in 1992.

Type specimen
The type specimen was collected by S. Jacobs and J. Clarkson near Mareeba, Queensland, Australia on the 26th of July 1987.

Placement within Nymphaea
It is placed in Nymphaea subgenus Anecphya.

Separation of Nymphaea kimberleyensis
The subspecies Nymphaea immutabilis subsp. kimberleyensis S.W.L.Jacobs was described in 1992. Later in 2011, it was elevated to a separate species Nymphaea kimberleyensis (S.W.L.Jacobs) S.W.L.Jacobs & Hellq.

Etymology
The specific epithet immutabilis, meaning unchanging, references the floral colouration, which does not change as the flower ages.

Conservation
The NCA status of Nymphaea immutabilis is Special Least Concern (SL). In the Northern Territory it is categorised as vulnerable.

Habitat
It occurs in swamps, permanent, or temporary waters, billabongs, streams, and rivers.