Ceratophyllaceae is a

cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 Hotels and resorts * Cosmopoli ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants t ...

s including one living genus commonly found in ponds, marshes, and quiet streams in tropical and in temperate regions. It is the only

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

family in the order Ceratophyllales. Species are commonly called coontails or hornworts, although hornwort is also used for unrelated plants of the division Anthocerotophyta. Living ''Ceratophyllum'' grows completely submerged, usually, though not always, floating on the surface, and does not tolerate drought.

Taxonomy

Ceratophyllaceae was considered a relative of

Nymphaeaceae Nymphaeaceae () is a family of flowering plants, commonly called water lilies. They live as rhizomatous aquatic herbs in temperate and tropical climates around the world. The family contains nine genera with about 70 known species. Water ...

and included in Nymphaeales in the

Cronquist system The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of Flowering Plants'' (1968; 2nd edition, 1988) ...

, but research has shown that it is not closely related to Nymphaeaceae or any other extant plant family. Some early molecular phylogenies suggested it was the

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to all other angiosperms, but more recent research suggests that it is the sister group to the

eudicots The eudicots, Eudicotidae, or eudicotyledons are a clade of flowering plants mainly characterized by having two seed leaves upon germination. The term derives from Dicotyledons. Traditionally they were called tricolpates or non-magnoliid dicot ...

. The APG III system placed the family in its own order, the Ceratophyllales.Kew World Checklist of Selected Plant Families
/ref>Angiosperm Phylogeny Web

/ref> The

APG IV system The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was published ...

accepts the phylogeny shown below:

Genera

The family contains one living genus, and several extinct genera described from the fossil record, including one of the earliest fruit bearing (in the form of an achene) plants, the Dakota formation freshwater plant Donlesia from Early Cretaceous. *''

Ceratophyllum ''Ceratophyllum'' is a cosmopolitan genus of flowering plants including four accepted living species in 2016, commonly found in ponds, marshes, and quiet streams in tropical and in temperate regions. It is the only extant genus in the family Ce ...

'' *†'' Ceratostratiotes'' *†'' Donlesia'' *?†''

Montsechia ''Montsechia'' is an extinct genus of aquatic plants containing the species ''Montsechia vidalii'', discovered in Spain. ''Montsechia vidalii'' lived about 130 million years ago, during the Barremian age, and appears to be the earliest known flo ...

References

{{Taxonbar, from=Q12012524 Freshwater plants Angiosperm families