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Nymphaeales

 
Sci-Tech Dictionary: Nymphaeales
(′nim·fē′ā·lēz)

(botany) An order of flowering aquatic herbs in the subclass Magnoliidae; all lack cambium and vessels and have laminar placentation.


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Sci-Tech Encyclopedia: Nymphaeales
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An order of flowering plants that have previously been included in the same larger grouping as Magnoliales, the Magnoliidae. Deoxyribonucleic acid (DNA) sequence studies have demonstrated that Nymphaeales as previously defined contain two families, Ceratophyllaceae (water hornwort) and Nelumbonaceae (lotus), that are not closely related to the others. Remaining in the order is the family Nymphaeaceae, the waterlilies, from which a small group of tropical plants, Cabombaceae, are split by some scientists. Nymphaeaceae contain nearly 100 species of fresh-water aquatics that are typically found in river and lake systems throughout the world. The ovaries of these plants are filled with mucilage, which mediates pollen tube growth from the stigmas to the ovules, and they have either inappertuate or monosulcate pollen. A spectacular plant is the Amazonian water lily (Victoria), which has leaves up to 15 ft (5 m) in diameter. The water lily family has been shown by DNA analyses to be one of the oldest lineages of flowering plants and distantly related to all others as well. The family members are relics of the early diversification of the flowering plants. See also Eumagnoliids; Plant kingdom; Pollen.


Wikipedia: Nymphaeales
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Nymphaeales
Fossil range: 130 Ma
Early Cretaceous - Recent

Scientific classification
Kingdom: Plantae
Division: Angiospermae
Class: see text
Order: Nymphaeales
Dumortier
Families

Nymphaeaceae
Cabombaceae
Hydatellaceae

Nymphaeales is a botanical name at the rank of order. When recognized, it includes water lilies and sometimes other aquatic plants. This order is not part of the APG II system's 2003 plant classification (unchanged from the APG system of 1998), which instead has a broadly circumscribed family Nymphaeaceae (including Cabombaceae) unplaced in any order. It is recognized by some systems of plant taxonomy, but others use different placements for the families in this order. In particular some plant systematists using the APG II system now use this order and circumscribe it to include the Nymphaeaceae and Cabombaceae. A 2007 study has found that Hydatellaceae also belongs to this group.[1]

This order is considered to be a basal, or early diverging, group of angiosperms. The families of this order are united by being families of aquatic herbs and are known from the fossil record as early as the Lower Cretaceous.

Contents

Fossils

The fossil record consists especially of seeds, and also pollen, stems, leaves, and flowers. It extends back to the Cretaceous.[2][3]

It is possible that the aquatic plant fossil Archaefructus belongs to this group.[4]

Classification

The current phylogenetic placement (based on the APG II system, with subsequent revisions) is:

Angiospermae

Amborella



Nymphaeales


Nymphaeaceae



Cabombaceae




Hydatellaceae





Austrobaileyales



Mesangiospermae

Chloranthaceae



magnoliids



Ceratophyllum



monocots



eudicots





The family Cambombaceae is included within the Nymphaeaceae in the APG II system, but may optionally be recognized separately.

Cronquist

The Cronquist system, of 1981, placed it in subclass Magnoliidae, in class Magnoliopsida [=dicotyledons] of division Magnoliophyta [=angiosperms]. It used this circumscription:

  • order Nymphaeales

Thorne (1992)

The Thorne system (1992) placed it in superorder Nymphaeanae in subclass Magnoliideae [=dicotyledons] in class Magnoliopsida [=angiosperms]. It used this circumscription:

  • order Nymphaeales
  • family Cabombaceae
  • family Nymphaeaceae

Dahlgren

The Dahlgren system placed it in superorder Nymphaeanae, in subclass Magnoliideae [=dicotyledons], in class Magnoliopsida [=angiosperms]. It used this circumscription:

  • order Nymphaeales
  • family Cabombaceae
  • family Nymphaeaceae
  • family Ceratophyllaceae

References

  1. ^ Saarela et al (2007). "Hydatellaceae identified as a new branch near the base of the angiosperm phylogenetic tree". Nature 446 (7133): 312–5. doi:10.1038/nature05612. PMID 17361182. 
  2. ^ "Nymphaeales: Fossil Record". University of California Museum of Paleontology. http://www.ucmp.berkeley.edu/anthophyta/paleoherbs/nymphfr.html. 
  3. ^ Else Marie Friis, Kaj Raunsgaard Pedersen and Peter R. Crane (15 March 2001). "Fossil evidence of water lilies (Nymphaeales) in the Early Cretaceous". Nature 410: 357–360. doi:10.1038/35066557. PMID 11268209. 
  4. ^ Soltis, D. E. (published June 2008). "The Year in Evolutionary Biology 2008". Ann. N.Y. Acad. Sci. 1133: 3–25. doi:10.1196/annals.1438.005. PMID 18559813. http://www.annalsnyas.org/cgi/content/abstract/1133/1/3. 
  • Simpson, M.G. Plant Systematics. Elsevier Academic Press. 2006.

 
 
Learn More
Ceratophyllaceae (botany)
Nelumbonaceae (botany)
Nymphaeaceae (botany)

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