(botany) An order of flowering aquatic herbs in the subclass Magnoliidae; all lack cambium and vessels and have laminar placentation.
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.
| Nymphaeales Temporal range: 130–0 Ma Early Cretaceous - Recent |
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| Nymphaea lotus | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| Order: | Nymphaeales Salisb. ex Bercht. & J.Presl |
| Families | |
Nymphaeales is an order of plants, which consists of water lilies and other aquatic plants.
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.
The fossil record consists especially of seeds, and also pollen, stems, leaves, and flowers. It extends back to the Cretaceous.[1][2]
It is possible that the aquatic plant fossil Archaefructus belongs to this group.[3]
The Nymphaeales currently includes three families and about 65 to 80 species.
order Nymphaeales
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| The classification of Nymphaeales and phylogeny within the flowering plants, as of APG III (2009). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
This order was not part of the APG II system's 2003 plant classification (unchanged from the APG system of 1998), which instead had a broadly circumscribed family Nymphaeaceae (including Cabombaceae) unplaced in any order. The APG III system did separate Cabombaceae from Nymphaeaceae and place them in the order Nymphaeales together with Hydatellaceae. This Hydatellaceae was placed among the monocots in previous systems, but a 2007 study found that the family belongs to this group.[4]
Some earlier systems, such as Cronquist's system of 1981, often included the Ceratophyllaceae and Nelumbonaceae in the Nymphaeales. Although, the Takhtajan system of 1980 separated the Nelumbonales, the new order was retained alongside the Nymphaeales in the superorder Nymphaeanae.
The Cronquist system placed the Nymphaeales in subclass Magnoliidae, in class Magnoliopsida [=dicotyledons]. In addition, Cronquist included the Ceratophyllaceae and split the family Barclayaceae from the Nymphaeaceae. Under the APG II system, the family Cambombaceae was included within the Nymphaeaceae, but could optionally be recognized separately. As of APG III, the two families are recognized separately.
The Dahlgren system placed Nymphaeales together with the Piperales in superorder Nymphaeanae, within subclass Magnoliideae (dicotyledons). Thorne's 1992 system (and 2000 revision) placed Nymphaeales as the sole order in the superorder Nymphaeanae within subclass Magnoliideae (=dicotyledons).
| APG III system[5] Nymphaeales |
Takhtajan system[6] Nymphaeales |
Cronquist system[7] Nymphaeales |
Dahlgren system[8] Nymphaeales |
Thorne system (1992)[9] & (2000)[10] Nymphaeales |
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| Hydatellaceae | among monocots, as Hydatellales | |||
| Cabombaceae | Cabombaceae
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Cabombaceae
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Cabombaceae | Cabombaceae
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| Nymphaeaceae | Nymphaeaceae
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Barclayaceae
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Nymphaeaceae | Nymphaeaceae
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Nymphaeaceae
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| sister to eudicot clade | Ceratophyllaceae | Ceratophyllaceae | Ceratophyllaceae | in Ranunculanae |
| placed in eudicot clade | in Nelumbonales | Nelumbonaceae | in Magnolianae | |
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