Haloragaceae (the watermilfoil
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
) is a
eudicot 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 th ...
family in the
order Saxifragales
The Saxifragales (saxifrages) are an order of flowering plants (Angiosperms). They are an extremely diverse group of plants which include trees, shrubs, perennial herbs, succulent and aquatic plants. The degree of diversity in terms of vege ...
, based on the
phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
APG system
The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved AP ...
. 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) a ...
, it was included in the order
Haloragales
Haloragales is an order of flowering plants. In the Cronquist system of classification, of 1981, it was placed in subclass Rosidae and had this circumscription:
* order Haloragales
*: family Haloragaceae (this includes water milfoil
''Myriop ...
.
Description
The Haloragaceae are very diverse in habit, including both small trees and submerged aquatics. Most members of the Haloragaceae are herbaceous, and most of those in turn are
perennial
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
s, though some species are
annual
Annual may refer to:
*Annual publication, periodical publications appearing regularly once per year
** Yearbook
** Literary annual
*Annual plant
*Annual report
*Annual giving
*Annual, Morocco, a settlement in northeastern Morocco
*Annuals (band), ...
s. In contrast however, members of the genus ''Haloragodendron'' are woody. Most species of ''Myriophyllum'' are
monoecious
Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy.
Monoecy is conne ...
while most other taxa have hermaphrodite flowers. The flowers are usually small and inconspicuous, but some genera can have more "showy" conspicuous flowers (''Haloragodendron'', ''Glischrocaryon''). Flowers are usually
radially symmetrical
Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, take the face of a human being which has a pla ...
, and unusual for
core eudicot
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 dicots ...
s,
merosity is (2-3)-4 parted. Petals are usually keeled or hooded when present. In ''Myriophyllum'' female flowers usually lack a perianth. They have (2-)4-8 stamens and an inferior ovary of (2-)4 carpels. In ''Myriophyllum'' the fruit is a schizocarp of 1-seeded 'nutlets' other genera can have nuts or drupes that can be winged or inflated.
Taxonomy
Phylogeny
Molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
studies, in particular, the
APG system
The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved AP ...
, placed the Haloragaceae within the
core eudicot
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 dicots ...
order,
Saxifragales
The Saxifragales (saxifrages) are an order of flowering plants (Angiosperms). They are an extremely diverse group of plants which include trees, shrubs, perennial herbs, succulent and aquatic plants. The degree of diversity in terms of vege ...
. Earlier versions of the APG had allowed either the broader circumscription (Haloragaceae ''
s.l.
SL may refer to:
Arts and entertainment
* SL (rapper), a rapper from London
* ''Second Life'', a multi-user 3D virtual world
* Sensei's Library, an Internet site dedicated to the game of Go
* Subdominant leittonwechselklänge
* Leica SL, a mirror ...
'') or a narrower Haloragaceae ''s.s.''.
Subdivision
History
Historically, the Haloragaceae included many disparate genera, since
segregated. A major
circumscription
Circumscription may refer to:
*Circumscribed circle
* Circumscription (logic)
*Circumscription (taxonomy)
*Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...
was carried out by
Schindler in 1905, dividing the "Halorrhagaceae" into two subfamilies (Halorrhagoideae and Gunneroideae) and the former into two tribes (Halorrhageae and Myriophylleae), with a total of seven genera. He removed some of the disparate genera and merged ''Gonocarpus'' and ''Meionectes'' into ''Haloragis''. This classification long remained the standard till Shaw (1966) removed ''
Gunnera
''Gunnera'' is the sole genus of herbaceous flowering plants in the family Gunneraceae, which contains 63 species. Some species in this genus, namely those in the subgenus ''Panke'', have extremely large leaves. Species in the genus are various ...
'' (into its own family Gunneraceae, within the order Gunnerales), the sole genus in Gunneroideae, leaving six genera. This situation remained until the monograph of Orchard (1975). Orchard restored ''Gonocarpus'' and split ''Haloragodendron'' from ''Haloragis'', leaving 8 genera.
List of genera, habitat, ''distribution'' (Number of species)
* Terrestrial
** ''
Glischrocaryon''
Endl.
Stephan Ladislaus Endlicher also known as Endlicher István László (24 June 1804, Pressburg, Bratislava (Pozsony) – 28 March 1849, Vienna) was an Austrian Empire, Austrian botanist, numismatist and Sinologist. He was a director of the Botan ...
''Australia'' (4)
** ''
Gonocarpus
:''The ''Gonocarpus'' of William Hamilton ("Ham.") is a synonym of ''Combretum.
''Gonocarpus'' (raspwort) is a genus of flowering plants in the family Haloragaceae. The species, which are native to Australia, New Zealand and Malesia, include:
* ...
''
Thunb.
Carl Peter Thunberg, also known as Karl Peter von Thunberg, Carl Pehr Thunberg, or Carl Per Thunberg (11 November 1743 – 8 August 1828), was a Swedish naturalist and an "apostle" of Carl Linnaeus. After studying under Linnaeus at Uppsala Un ...
''Australia, New Zealand, S. E. Asia'' (36)
** ''
Haloragis
''Haloragis'' is a genus of flowering plants in the family Haloragaceae. Some species are known commonly as seaberry and most are native to the southern hemisphere. They are annual or perennial herbs to small shrubs, and many are terrestrial wetl ...
''
J.R.Forst.
Johann Reinhold Forster (22 October 1729 – 9 December 1798) was a German Reformed (Calvinist) pastor and naturalist of partially Scottish descent who made contributions to the early ornithology of Europe and North America. He is best known ...
& G.Forst.
Johann George Adam Forster, also known as Georg Forster (, 27 November 1754 – 10 January 1794), was a German naturalist, ethnologist, travel writer, journalist and revolutionary. At an early age, he accompanied his father, Johann Reinhold F ...
''Australia, New Zealand, S. Pacific'' (26)
** ''Haloragodendron''
Orchard ''Australia'' (5)
* Semiaquatic
** ''Laurembergia''
P.J.Bergius ''Pantropical'' (4)
* Aquatic
** ''
Meziella''
Schindl. Anton Karl Schindler (15 August 1879 in Bremen – 1964) was a German dentist and botanist.
He studied botany at the universities of Göttingen, Strasbourg and Halle, receiving his doctorate at Erlangen in 1904. From 1905 to 1910 he conduct ...
''S. W. Australia'' (1)
** ''
Myriophyllum
''Myriophyllum'' (water milfoil) is a genus of about 69 species of freshwater aquatic plants, with a cosmopolitan distribution. The center of diversity for ''Myriophyllum'' is Australia with 43 recognized species (37 endemic).
These submersed ...
''
L. ''Cosmopolitan'' (60)
** ''
Proserpinaca
''Proserpinaca'', commonly called mermaidweed, is a genus of flowering plants in the watermilfoil family (Haloragaceae). It is a small genus, comprising only two to three Extant taxon, extant species, all of which are native to eastern North Amer ...
''
L. ''New World'' (3)
Molecular era
A molecular study resolved the infrafamilial relationships among the genera, resulting in some taxonomic revision, including redistribution of species. In addition, ''Meionectes'' was reinstated, separating two species from ''Haloragis'' and creating a new monotypic genus, ''Trihaloragis'' by segregating ''Gonocarpus hexandrus''. Consequently the number of genera is increased to ten, with the addition of:
* ''Meionectes''
R.Br. (2)
* ''Trihaloragis''
Moody & Les (1)
''Glischrocaryon''-''Haloragodendron'' is resolved as the
basal node
In phylogenetics, basal is the direction of the ''base'' (or root) of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to th ...
,
sister
A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to refer to ...
to the remaining family. While
monophyly
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...
of this group is well supported, monophyly of the two separate genera is less well supported, and suggests some
paraphyly
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...
. Thus the generic limits remain unresolved.
A subsequent, more detailed study of ''Myriophyllum'' demonstrated that the
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...
genus ''Meziella'' was embedded within it, leading to its submersion within the former as ''Myriophyllum'' subgenus ''Meziella'', thereby reducing the number of genera within the family to 9.
Species
As of 2014, the family has 138 species, distributed among the nine genera as follows:
* ''Glischrocaryon'' (4)
* ''Gonocarpus'' (36)
* ''Haloragis'' (24)
* ''Haloragodendron'' (6)
* ''Laurembergia'' (4)
* ''Myriophyllum'' (60)
* ''Proserpinaca'' (2)
* ''Meionectes'' (2)
* ''Trihaloragis'' (1)
Distribution and habitat
The distribution of the family is nearly worldwide. The center of species diversity is in
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
where all genera are found excepting ''Proserpinaca'' and ''Laurembergia''. Habitats vary from arid desert regions to freshwater lakes. The terrestrial genera (''Glischrocaryon'', ''Gonocarpus'', ''Haloragis'', ''Haloragodendron'', ''Trihaloragis'' ) are primarily limited to the
southern hemisphere. ''Meionectes'', ''Meziella'', ''Myriophyllum'' and ''Proserpinaca'' are aquatic, while ''Laurembergia'' are semiaquatic. ''Glischrocaryon'', ''Haloragodendron'', ''Meionectes'' and ''Trihaloragis'' are Australian
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
s, where about 70% of all species are found. For detailed maps of the distribution of each genus, see ''Figure 1''.
References
Bibliography
Books and theses
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** , in
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Articles
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Supplement
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Websites
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* (''see also''
Angiosperm Phylogeny Website
The Angiosperm Phylogeny Website (or APweb) is a website dedicated to research on angiosperm phylogeny and taxonomy.
The site is hosted by the Missouri Botanical Garden website and maintained by researchers, Peter F. Stevens and Hilary M. Davis ...
)
* , in
Flora of China online vol. 13
External links
*
*
{{Taxonbar, from=Q157237
Saxifragales families