Nymphaea gardneriana

Nymphaea gardneriana is a species of waterlily native to Cuba and tropical South America.

Vegetative characteristics
Nymphaea gardneriana is a polymorphic species. It exhibits a high degree of phenotypic plasticity and adapts its shape in response to different environmental conditions. Its stoloniferous rhizome is ovoid. Floating leaves have five, or rarely 4, primary veins. The leaf surface is glabrous and marked with irregular violet spotting. The colouration of the foliage varies with the light intensity it is exposed to. In direct sun, the leaves turn bright red due to anthocyanins, providing protection of tissues against radiation damage through sunlight.

Generative characteristics
The floating flowers are attached to the stem by an up to 6 mm wide, glabrous peduncle with 5-6 central primary and 10-12 peripheral secondary air channels. The floral fragrance has been described as very pleasant. It has also been described as pungent, fermented, fruity, or solvent-like. It is primarily composed of methyl hexanoate and methyl 2-methylbutanoate. The floral fragrance is primarily emitted from the innermost tepals, as well as petaloid stamens.

Cytology
The chromosome count is n = 14.

Vegetative reproduction
In most populations the main mode of reproduction is through the formation of stolons. Each individual plant is capable of forming many stolons.

Generative reproduction
In natural settings, fruits are rarely produced, although Nymphaea gardneriana easily sets fruit through artificial pollination in cultivation. Sexual reproduction occurs rarely and the main modus of reproduction relies on vegetative reproduction through stolons. It does not form tubiferous flowers.

Habitat
This adaptable plant can thrive in various freshwater environments. In rivers, it displays a submerged growth pattern, while in lakes, it develops floating leaves. For example, it has been documented in the Sucuri River in Brazil, known for its clear water. Additionally, it can be found in both natural and artificial lakes within the Pantanal, characterised by clayey soils and murky water rich in organic matter.

Taxonomy
It was first described by Jules Émile Planchon in 1852.

Type specimen
The type specimen was collected by Mr. G. Gardner in Brazil.

Placement within Nymphaea
It is placed in Nymphaea subgenus Hydrocallis.

Conservation
In Cuba, it is considered to be endangered. Current threats include the loss and degradation of habitats caused by blockage and pollution from waste, agricultural practices, subsistence livestock, and the impact of invasive species.

Ecology
Nymphaea gardneriana, among other Nymphaea species, serves as an important component in the trophic chain of aquatic ecosystems by providing shelter for aquatic organisms.

Pollination
Species of Nymphaea subgenus Hydrocallis are pollinated by beetles of the genus Cyclocephala.

Herbivory
There have been reports of birds seeking the rhizomes of Nymphaea gardneriana when the water levels in the swamp decline.

The articulated laticifers present in the two outer whorls of tepals may have a protective function against herbivores and microorganisms.

Cultivation
Nymphaea gardneriana is an uncommon in cultivation. It can be cultivated in clay, loam, or sandy soil. Propagating Nymphaea gardneriana is achievable through division.