Victoria species are rhizomatous, aquatic,[2][5] short-lived, perennial herbs with tuberous rhizomes bearing contractile[5] adventitious roots.[2] The floating leaves are peltate and orbicular.[2] The margin of the lamina is raised.[7] The lamina possesses stomatodes (i.e. microscopic perforations).[7][8][9] The abaxial leaf surface posesses prominent, reticulate venation.[2]
Generative characteristics
The up to 25 cm wide, nocturnal,[10] thermogenic,[11] solitary,[2] actinomorphic, chasmogamous, protogynous flowers[5] have prickly pedicels with 4 primary and 8 secondary air canals.[2] The flowers have four[12][7][2] prickly, petaloid, 12 cm long, and 7–8 cm wide sepals.[12] The 50-100 petals[5] gradually transition towards the shape of the stamens,[7] however there is an abrupt change between the innermost petals to the outermost staminodia.[12][10] The androeceum consists of 150–200 stamens.[12][5] The gynoecium consists of 30–44[5] fused carpels.[12] The 0–15 cm wide,[2] spiny,[12] irregularly dehiscencent fruit[5][12] bears arillate,[5][12] glabrous, smooth or granular seeds.[5] Proliferating pseudanthia are absent.[13]
Cytology
The ploidy level is 2x and the chromosome count ranges from 2n = 20 to 2n = 24.[2][14]
Taxonomy
VictoriaR.H.Schomb. was published by Robert Hermann Schomburgk in September 1837.[15][2] The type species is Victoria reginaR.H.Schomb.[3] The genus has two synonyms, both published within the same year with the same name: VictoriaLindl. published by John Lindley in October 1837 and VictoriaJ. E. Gray published by John Edward Gray in December 1837.[2] There is however disagreement over the correct taxon authority.[16]VictoriaR.H.Schomb. is seen as correct by several sources,[12][1][2] but VictoriaLindl. is also widely regarded as correct,[13][16][17][5] despite being published a month later.[2]
shallow waters of the Amazon River basin, such as oxbow lakes and bayous
The flowers are white the first night they are open and become pink the second night. They are up to 40 cm in diameter, and are pollinated by scarab beetles. According to Parodi, both V. amazonica and V. cruziana can occasionally produce flowers up to 50 centimetres (20 in) in width. The flower is depicted in the Guyanese coat of arms.[18]
Slightly smaller than V. amazonica, with the underside of the leaves purple rather than the red of V. amazonica, and covered with a peachlike fuzz lacking in V. amazonica. V. cruziana opens its flowers at dusk.
Leaves reaching more than 3 metres (9.8 ft) in width, larger seed and ovule size
Evolutionary relationships
Together with the genus Euryale, Victoria may be placed within the genus Nymphaea, rendering it paraphyletic in its current circumscription.[20][21][22][23][24]
^ abcdefghijkPellegrini, M.O.O. Nymphaeaceae in Flora e Funga do Brasil. Jardim Botânico do Rio de Janeiro. Available at: https://floradobrasil.jbrj.gov.br/FB24052 consulta.publica.uc.citacao.acesso.em28 Nov. 2024
^ abWarner, K. A., Rudall, P. J., & Frohlich, M. W. (2008). Differentiation of Perianth Organs in Nymphaeales. Taxon, 57(4), 1096–1109. http://www.jstor.org/stable/27756767