''Nymphaea gigantea'', commonly known as the giant waterlily or blue waterlily, is a

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of ...

plant in the family

Nymphaeaceae Nymphaeaceae () is a family of flowering plants, commonly called water lilies. They live as rhizomatous aquatic herbs in temperate climate, temperate and tropical climates around the world. The family contains five genera with about 70 know ...

which is native to parts of northern and eastern Australia, and possibly New Guinea, and has been widely cultivated elsewhere. It is an aquatic plant whose natural habitat is permanent and semi-permanent still water bodies.

Description

The giant waterlily has a

rhizomatous In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

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. The rhizome is

globose This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary ...

, the large floating leaves are orbicular to slightly egg-shaped, and

cordate Cordate is an adjective meaning ' heart-shaped' and is most typically used for: * Cordate (leaf shape), in plants * Cordate axe, a prehistoric stone tool See also * Chordate A chordate ( ) is a bilaterian animal belonging to the phyl ...

(i.e. the petiole, or leaf stem, attaches to the leaf blade at the base of a deep radial cleft). They measure up to diameter and are

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

(hairless) on both sides, with regularly-spaced teeth along the margins measuring about long. The large flowers are solitary and up to diameter. They are held on a rigid, upright peduncle that may extend up to above the water surface. They have four green

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s that measure about long and sometimes have blue or purple streaks, and up to 32

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s that are initially lilac or blue but fade to almost white with age. The fruit is – in botanical terms – a

berry A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit although many pips or seeds may be present. Common examples of berries in the cul ...

. After fertilisation of the flower it is drawn underwater by the contraction of the peduncle (i.e. the flower stalk), where the fruit ripens just below the surface. They are roughly the size of an apple and may contain up to 3,000 seeds.

Phenology

Flowering occurs throughout the year, but is more common in warmer months. The flowers are open during the day and closed at night.

Cytology

The chromosome count is n = 112. The genome size is 2709.06 Mb.

Taxonomy

''Nymphaea gigantea'' was first described in 1852 by the English botanist and illustrator

William Jackson Hooker Sir William Jackson Hooker (6 July 178512 August 1865) was an English botany, botanist and botanical illustrator, who became the first director of Kew Gardens, Kew when in 1841 it was recommended to be placed under state ownership as a botan ...

in The Botanical Magazine, based on material collected by

John Carne Bidwill John Carne Bidwill (5 February 1815 – 16 March 1853) was an English botanist who documented plant life in New Zealand and Australia. He is attributed with the discovery of several Australian plant species. Life in England Bidwill wa ...

from the Wide Bay area of

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

(at that time still a part of the

colony of New South Wales The Colony of New South Wales was a colony of the British Empire from 1788 to 1901, when it became a State of the Commonwealth of Australia. At its greatest extent, the colony of New South Wales included the present-day Australian states of New ...

). The description was accompanied by an illustration by

Walter Hood Fitch Walter Hood Fitch (28 February 1817 – 14 January 1892) was a botanical illustrator, born in Glasgow, Scotland, who executed some 10,000 drawings for various publications. His work in colour lithograph, including 2700 illustrations for ''C ...

detailing the flower.

Distribution and habitat

The range of the giant waterlily in Australia is from northeastern

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

, through eastern and northern

, northern parts of the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

, and the far northeast of

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. Some non-authoritative sources claim it is also native to New Guinea. The habitat is permanent and semi-permanent waters of lakes, billabongs, and sluggish rivers where the bottom is deep mud and the water depth is at least .

Conservation

This species is listed by the Queensland Government's Department of Environment, Science and Innovation as "special least concern", a rating unique to Queensland which is ranked between "

least concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

" and "

near threatened A near-threatened species is a species which has been Conservation status, categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to Endangered species, endangerment in the ne ...

". , this species has not been assessed by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

(IUCN).

Cultivation

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

Uses

Various parts of ''Nymphaea gigantea'' are edible and the plant was an important staple food for

indigenous Australians Indigenous Australians are people with familial heritage from, or recognised membership of, the various ethnic groups living within the territory of contemporary Australia prior to History of Australia (1788–1850), British colonisation. The ...

across the northern parts of Australia. The golfball-sized

tuber Tubers are a type of enlarged structure that plants use as storage organs for nutrients, derived from stems or roots. Tubers help plants perennate (survive winter or dry months), provide energy and nutrients, and are a means of asexual reproduc ...

s were collected from the muddy bottoms of water bodies by indigenous women and roasted before eating. The flower buds and peeled stalks were eaten raw, and the seeds could either be eaten on their own after roasting the whole fruit, or were pounded to make a flour for damper.

Gallery

File:Nymphaea gigantea 184015407.jpg, In natural habitat, southern Queensland, March 2022 File:Nymphaea gigantea 183879021.jpg, Southern Queensland, March 2022 File:Nymphaeales - Nymphaea gigantea 14.jpg, Leaves (cultivated at

Kew Gardens Kew Gardens is a botanical garden, botanic garden in southwest London that houses the "largest and most diverse botany, botanical and mycology, mycological collections in the world". Founded in 1759, from the exotic garden at Kew Park, its li ...

)

References

External links

* *
View a map
of historical sightings of this species at the

Australasian Virtual Herbarium The ''Australasian Virtual Herbarium'' (AVH) is an online resource that allows access to plant specimen data held by various Australian and New Zealand herbaria. It is part of the Atlas of Living Australia (ALA), and was formed by the amalgama ...

View observations
of this species on

iNaturalist iNaturalist is an American 501(c)(3) nonprofit social network of naturalists, citizen scientists, and biologists built on the concept of mapping and sharing observations of biodiversity across the globe. iNaturalist may be accessed via its web ...

View images
of this species on Flickriver {{Taxonbar, from=Q150010 gigantea Flora of New South Wales Flora of Queensland Flora of the Northern Territory Flora of Western Australia Aquatic plants