Ceratophyllaceae is a
cosmopolitan 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 ...
of
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...
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
Hornworts are a group of non-vascular Embryophytes (land plants) constituting the division Anthocerotophyta (). The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, hornworts have a ...
.
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
The Nymphaeales are an order of flowering plants, consisting of three families of aquatic plants, the Hydatellaceae, the Cabombaceae, and the Nymphaeaceae (water lilies). It is one of the three orders of basal angiosperms, an early-diverging ...
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 dic ...
. The
APG III APG is an abbreviation with several different meanings:
* Aberdeen Proving Ground, a United States Army installation in Aberdeen, Maryland, also
**Phillips Army Airfield, the airfield of the above, from its IATA airport code
* Aboriginal Provisiona ...
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 publish ...
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.
References
{{Taxonbar, from=Q12012524
Freshwater plants
Angiosperm families