Victoria or giant waterlily is a genus of aquatic herbs in the plant family Nymphaeaceae. Its leaves have a remarkable size: Victoria boliviana produces leaves up to 3.2 m in width. The genus name was given in honour of Queen Victoria of the United Kingdom.

Description

Vegetative characteristics

Victoria species are rhizomatous, aquatic, short-lived, perennial herbs with tuberous rhizomes bearing contractile adventitious roots. The floating leaves are peltate and orbicular. The margin of the lamina is raised. The lamina possesses stomatodes (i.e. microscopic perforations). The abaxial leaf surface posesses prominent, reticulate venation.

Generative characteristics

The up to 25 cm wide, nocturnal, thermogenic, solitary, actinomorphic, chasmogamous, protogynous flowers have prickly pedicels with 4 primary and 8 secondary air canals. The flowers have four prickly, petaloid, 12 cm long, and 7–8 cm wide sepals. The 50-100 petals gradually transition towards the shape of the stamens, however there is an abrupt change between the innermost petals to the outermost staminodia. The androeceum consists of 150–200 stamens. The gynoecium consists of 30–44 fused carpels. The 0–15 cm wide, spiny, irregularly dehiscencent fruit bears arillate, glabrous, smooth or granular seeds. Proliferating pseudanthia are absent.

Cytology

The ploidy level is 2x and the chromosome count ranges from 2n = 20 to 2n = 24.

Taxonomy

Victoria R.H.Schomb. was published by Robert Hermann Schomburgk in September 1837. The type species is Victoria regina R.H.Schomb. The genus has two synonyms, both published within the same year with the same name: Victoria Lindl. published by John Lindley in October 1837 and Victoria J. E. Gray published by John Edward Gray in December 1837. There is however disagreement over the correct taxon authority. Victoria R.H.Schomb. is seen as correct by several sources, but Victoria Lindl. is also widely regarded as correct, despite being published a month later.

Species

Evolutionary relationships

Together with the genus Euryale, Victoria may be placed within the genus Nymphaea, rendering it paraphyletic in its current circumscription.

Ecology

Habitat

It occurs in lakes and streams.

Pollination

Victoria flowers are pollinated by Cyclocephala beetles.

Use

Horticulture

Victoria is a popular ornamental plant.

Food

The seeds, petioles, and rhizomes are used as food.

Other uses

Root extracts are used as black dye.