Nymphaeales is an order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 of plants, which consists of water lilies

Nymphaeaceae

Nymphaeaceae is a family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus...

 and other aquatic plant

Aquatic plant

Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...

s.

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.

Fossils

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

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

.

It is possible that the aquatic plant fossil Archaefructus

Archaefructus

Archaefructus is an extinct genus of herbaceous aquatic seed plants with 3 known species. Fossil material assigned to this genus originates from the Yixian Formation in northeastern China, originally dated as late Jurassic but now thought to be approximately 125 million years old, or early...

belongs to this group.

Classification

The Nymphaeales currently includes three families and about 65 to 80 species.

order Nymphaeales Cabombaceae Cabombaceae Cabombaceae is the botanical name of a family of flowering plants. The family has been recognised as distinct by at least some taxonomists and by APG III... Brasenia Brasenia Brasenia is a genus belonging to the family Cabombaceae, consisting of one extant species widely distributed in warm temperate and tropical regions of the world. Brasenia is an aquatic perennial plant with floating, peltate leaves and rhizomatous stems... (1 species) Cabomba Cabomba Cabomba is an aquatic plant genus, one of two belonging to the family Cabombaceae. It has divided submerged leaves in the shape of a fan and is much favoured by aquarists as an ornamental and oxygenating plant for fishtanks... (5 species) Hydatellaceae Hydatellaceae Hydatellaceae are small, aquatic flowering plants. The family includes the genus Trithuria, which has been recently re-defined to include the genus Hydatella. The family consists of about a dozen species. These tiny , relatively simple, aquatic plants occur in Australasia and India. The simple... Trithuria (7 species) Nymphaeaceae Nymphaeaceae Nymphaeaceae is a family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus... Barclaya Barclaya Barclaya is a genus of 3 - 4 species of flowering plants usually included in the family Nymphaeaceae but sometimes given their own family status as Barclayaceae on the basis of an extended perianth tube arising from the top of the ovary and by stamens that are joined basally. Barclaya are aquatic... (3-4 species) Euryale Euryale Euryale , in Greek mythology, was the second eldest one of the Gorgons, three vicious sisters with brass hands, sharp fangs, and hair of living, venomous snakes. She and her sister Stheno, unlike their sister, Medusa, were not able to turn any creature to stone with her gaze... (1 species) Nuphar Nuphar Nuphar is genus of aquatic plants in the family Nymphaeaceae, with a temperate to subarctic Northern Hemisphere distribution. Common names include water-lily , pond-lily, and spatterdock .A total of eight species and three hybrids are currently accepted in the genus... (10-12 species) Nymphaea Nymphaea Nymphaea is a genus of aquatic plants in the family Nymphaeaceae. There are about 50 species in the genus, which has a cosmopolitan distribution.-Name:The common name, shared with some other genera in the same family, is Water Lily.... (35-50 species) Victoria Victoria (genus) Victoria may refer to :* Victoria , a moth genus in the family Geometridae* Victoria , a waterlily genus in the family Nymphaeaceae... (2 species)	{clade| style=font-size:75%;line-height:75%	label1=Angiospermae	1= }}
The classification of Nymphaeales and phylogeny Phylogenetics In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...  within the flowering plants, as of APG III (2009).

This order was not part of the APG II system's

APG II system

The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...

 2003 plant classification (unchanged from the APG system

APG system

The APG system of plant classification is the first, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in 1998 by the Angiosperm Phylogeny Group. It was superseded in 2003 by a revision, the APG II system, and then in 2009 by a further...

 of 1998), which instead had a broadly circumscribed family Nymphaeaceae

Nymphaeaceae

Nymphaeaceae is a family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus...

 (including Cabombaceae

Cabombaceae

Cabombaceae is the botanical name of a family of flowering plants. The family has been recognised as distinct by at least some taxonomists and by APG III...

) unplaced in any order. The APG III system

APG III system

The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy...

 did separate Cabombaceae from Nymphaeaceae and place them in the order Nymphaeales together with Hydatellaceae. This Hydatellaceae

Hydatellaceae

Hydatellaceae are small, aquatic flowering plants. The family includes the genus Trithuria, which has been recently re-defined to include the genus Hydatella. The family consists of about a dozen species. These tiny , relatively simple, aquatic plants occur in Australasia and India. The simple...

 was placed among the monocots in previous systems, but a 2007 study found that the family belongs to this group.

Some earlier systems, such as Cronquist's system of 1981, often included the Ceratophyllaceae and Nelumbonaceae in the Nymphaeales. Although, the Takhtajan system

Takhtajan system

A system of plant taxonomy, the Takhtajan system of plant classification was published by Armen Takhtajan, in several versions from the 1950s onwards. It is usually compared to the Cronquist system. Key publications:-External links:* Takhtajan system at...

 of 1980 separated the Nelumbonales, the new order was retained alongside the Nymphaeales in the superorder Nymphaeanae.

The Cronquist system

Cronquist system

The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in his texts An Integrated System of Classification of Flowering Plants and The Evolution and Classification of Flowering Plants .Cronquist's system places flowering plants into two...

 placed the Nymphaeales in subclass Magnoliidae

Magnoliidae

Magnoliids are a group of about 9,000 species of flowering plants, including magnolias, nutmeg, bay laurel, cinnamon, avocado, black pepper, and many others. They are characterized by trimerous flowers, pollen with one pore, and usually branching-veined leaves.-Classification:Traditionally,...

, in class Magnoliopsida

Magnoliopsida

Magnoliopsida is a valid botanical name for a class of flowering plants. By definition the class will include the family Magnoliaceae, but its circumscription can otherwise vary, being more inclusive or less inclusive depending upon the classification system being discussed.-Cronquist and...

 [=dicotyledons]. In addition, Cronquist included the Ceratophyllaceae and split the family Barclayaceae from the Nymphaeaceae. Under the APG II system

APG II system

The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...

, the family Cambombaceae was included within the Nymphaeaceae, but could optionally be recognized separately. As of APG III

APG III system

The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy...

, the two families are recognized separately.

The Dahlgren system

Dahlgren system

One of the modern systems of plant taxonomy, the Dahlgren system was published by monocot specialist Rolf Dahlgren. His wife Gertrud Dahlgren carried on after his death.According to the extensive listing by Professor Reveal One of the modern systems of plant taxonomy, the Dahlgren system was...

 placed Nymphaeales together with the Piperales

Piperales

Piperales is a botanical name for an order of flowering plants. It necessarily includes the family Piperaceae but otherwise has been treated variously over time...

 in superorder Nymphaeanae, within subclass Magnoliideae (dicotyledons). Thorne's 1992 system

Thorne system (1992)

A modern system of plant taxonomy, the Thorne system of plant classification was drawn up by the botanist Robert F. Thorne . He replaced it in 2000 with a new system. These two systems were published in:...

 (and 2000 revision) placed Nymphaeales as the sole order in the superorder Nymphaeanae within subclass Magnoliideae (=dicotyledons).

Comparison of the Nymphaeales across five systems

APG III system APG III system The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy... Nymphaeales	Takhtajan system Takhtajan system A system of plant taxonomy, the Takhtajan system of plant classification was published by Armen Takhtajan, in several versions from the 1950s onwards. It is usually compared to the Cronquist system. Key publications:-External links:* Takhtajan system at... Nymphaeales	Cronquist system Cronquist system The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in his texts An Integrated System of Classification of Flowering Plants and The Evolution and Classification of Flowering Plants .Cronquist's system places flowering plants into two... Nymphaeales	Dahlgren system Dahlgren system One of the modern systems of plant taxonomy, the Dahlgren system was published by monocot specialist Rolf Dahlgren. His wife Gertrud Dahlgren carried on after his death.According to the extensive listing by Professor Reveal One of the modern systems of plant taxonomy, the Dahlgren system was... Nymphaeales	Thorne system (1992) Thorne system (1992) A modern system of plant taxonomy, the Thorne system of plant classification was drawn up by the botanist Robert F. Thorne . He replaced it in 2000 with a new system. These two systems were published in:...  & (2000) Nymphaeales
Hydatellaceae Hydatellaceae Hydatellaceae are small, aquatic flowering plants. The family includes the genus Trithuria, which has been recently re-defined to include the genus Hydatella. The family consists of about a dozen species. These tiny , relatively simple, aquatic plants occur in Australasia and India. The simple...	among monocots, as Hydatellales
Cabombaceae Cabombaceae Cabombaceae is the botanical name of a family of flowering plants. The family has been recognised as distinct by at least some taxonomists and by APG III...	Cabombaceae Cabombaceae Cabombaceae is the botanical name of a family of flowering plants. The family has been recognised as distinct by at least some taxonomists and by APG III... Brasenia, Cabomba	Cabombaceae Cabombaceae Cabombaceae is the botanical name of a family of flowering plants. The family has been recognised as distinct by at least some taxonomists and by APG III... Brasenia, Cabomba	Cabombaceae Cabombaceae Cabombaceae is the botanical name of a family of flowering plants. The family has been recognised as distinct by at least some taxonomists and by APG III...	Cabombaceae Cabombaceae Cabombaceae is the botanical name of a family of flowering plants. The family has been recognised as distinct by at least some taxonomists and by APG III... Brasenia, Cabomba
Nymphaeaceae Nymphaeaceae Nymphaeaceae is a family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus...	Nymphaeaceae Nymphaeaceae Nymphaeaceae is a family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus... subf. Barclayoideae, Euryaloideae, Nymphaeoideae	Barclayaceae Barclaya	Nymphaeaceae Nymphaeaceae Nymphaeaceae is a family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus...	Nymphaeaceae Nymphaeaceae Nymphaeaceae is a family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus... Barclaya, Euryale, Nuphar, Nymphaea, Ondinea, Victoria
		Nymphaeaceae Nymphaeaceae Nymphaeaceae is a family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus... Euryale, Nuphar, Nymphaea, Ondinea, Victoria
sister to eudicot clade	Ceratophyllaceae	Ceratophyllaceae	Ceratophyllaceae	in Ranunculanae
placed in eudicot clade	in Nelumbonales	Nelumbonaceae	in Magnolianae