Neotropical Nymphaeaceae

Lidyanne Yuriko Saleme Aona* and Daniela Zappi**

Universidade Federal do Recôncavo da Bahia (UFRB)*
Royal Botanic Gardens, Kew, UK.**  

Description

Perennial, rarely annual aquatic herbs with rhizomes. Leaves simple, alternate, floating, emergent or submersed, petiole long; leaf-blade rounded, cordate to peltate, sometimes spiny underneath. Flowers on the water surface (above only in Nuphar Sm.), solitary, with a long pedicel attached to the rhizome, sepals and petals intergrading, sepals 4-6(-12), free to adnate to the ovary, petals 6-70, spiralled or the outer ones 4-verticillate, rarely absent, frequently with a gradual transition to stamens or staminodes, stamens 14-700, spirally arranged, anthers with 2 thecae, introrse, longitudinally dehiscent, ovary superior to inferior, carpels 3-50, totally or partially fused, stigmas sessile, equalling the number of carpels; ovules many, placentation laminar. Fruit a leathery berry or an irregularly dehiscent capsule; few to numerous seeds ovoid to globose, sometimes arillate, testa glabrous to hairy, embryo small, endosperm scant, perisperm abundant, cotyledons 2.

Notes on delimitation

  • Nymphaeaceae is in the order Nymphaeales together with Cabombaceae and Hydatellaceae.
  • Saarela et al. (2007) suggest a few additional possible synapomorphies for Nymphaeales, such as hydrolysable tannins in this group (e.g. in Nuphar) being different to those found elsewhere (Gottlieb et al. 1993; Ishimatsu et al. 1989), although Hydatellaceae are still very poorly known.

Distribution in the Neotropics

  • Nuphar (c. 11, north temperate, North America, Europe, and Asia), of which Nuphar lutea Sibth. & Sm. is cultivated in the Neotropics.
  • Nymphaea L. (15 - 20 species in the Neotropics). 
  • Victoria Lindl. (2 - 3 species, Tropical America, mainly in the Amazon region). 

Distinguishing characters (always present)

Nymphaeaceae are the best known waterlilies with:

  • Large flowers and usually many free perianth parts and stamens disposed spirally.
  • Many ovules in each carpel, the placentation usually being clearly laminar (Stevens 2008).
  • The stems are not free floating, as the plants are essentially rooted, and the leaves are disposed in rosettes attached to the rhizome.
  • The root endodermis has a Casparian strip.

Other important characters

  • Flowers showy, relatively large.
  • Stigmas sessile.

Key differences from similar families

Nymphaeaceae are closely related to the Cabombaceae, sharing with them:

However, Nymphaeaceae has relatively large, showy flowers with 4-6(-12) sepals and 6(-70) petals, while Cabombaceae have considerably fewer perianth parts and the flowers are less conspicuous.

Number of genera

Three Neotropical genera: Nuphar, Nymphaea and Victoria.

Useful tips for generic identification

Nymphaeaceae is subdivided into 2 subfamilies:

  • Nupharoideae, with stout, creeping rhizomes, roots with 10-18 xylem poles, pith large; fruit emergent (Nuphar); chromosome n = 17.
  • Nymphaeoideae, roots with 5-9 xylem poles, pith small, if any; fruit maturation underwater; chromosome n = 10, 12, 14-18 (Nymphaea, Victoria).

Notable genera and distinguishing features

Nuphar: distinguished by its rounded petals and emergent fruit.
Nymphaea: water lilies with acute petals, leaves without thorns.
Victoria: this genus has acute, very numerous petals, thorns or spines in the outside side of its leaves, petioles, peduncles and outer sepals, the leaf margin is distinctly folded upwards. 

Status

  • Nympheaceae is a predominantly Temperate family, although Victoria amazonica Sowerby and V. cruziana Orbign. are found in the Amazon river.
  • Many species are used in horticulture.
  • Nuphar is introduced (cultivated).

General notes

  • Nymphaeaceae are often pollinated by beetles, and sometimes their flowers open at night
  • Protogyny has been studied in Victoria amazonica (Prance 1975, 1980).

Important literature

Feres, F. & Amral, M.C.E. 2003. Nyphaeaceae. In Wanderley, M. G. L., Shepherd, G. J. & Giulietti, A. M. (Eds.). Flora Fanerogâmica do Estado de São Paulo. Vol. 3. São Carlos, Editora RiMA. pp: 241-245.

Gottlieb, O., R., Kaplan, M. A. C., & Kubitzki, K. 1993. A suggested role of galloyl esters in the evolution of dicotyledons. Taxon 42: 539-552.

Ishimatsu, M., Tanaka, T., Nonaka, G., Nishioka, I., Nishizawa, M., & Yamagishi, T. 1989. Tannins and related compounds. LXXIX. Isolation and characterisation of novel dimeric and trimeric hydrolyzable tannins, nuphrins C, D, E and F, from Nuphar japonicum DC. Chem. Pharmac. Bull. 37: 1735-1743.

Prance, G.T. & Arius, J.R. 1975. A study of the floral biology of Victoria amazonica (Poepp.) Sowerby (Nymphaeaceae). Acta Amazonica 5 (2): 109-139. 1975.

Prance, G.T. 1980. A note on the pollination of Nymphaea amazonum Mart. & Zucc. (Nymphaeaceae). Brittonia 32(4): 505 - 507.

Saarela, J. M., Rai, H. S., Doyle, J. A., Endress, P. K., Mathews, S., Marchant, A. D., Briggs, B., & Graham, S. W. 2007. Hydatellaceae identified as a new branch near the base of the angiosperm phylogenetic tree. Nature 446: 312-315.

Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 [and more or less continuously updated since]. http://www.mobot.org/MOBOT/research/APweb/.

How to cite

Aona, L.Y.S. & Zappi, D.C. (2009). Neotropical Nymphaeaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/neotropikey/families/Nymphaeaceae.htm.