The family includes both freshwater and marine aquatics. They are found throughout the world in a wide variety of habitats, but are primarily tropical.
The species are annual or perennial, with a creeping monopodial rhizome with the leaves arranged in two vertical rows, or an erect main shoot with roots at the base and spirally arranged or whorled leaves. The leaves are simple and usually found submerged, though they may be found floating or partially emerse. As with many aquatics they can be quite variable in shape – from linear to orbicular, with or without a petiole, and with or without a sheathing base.
The flowers are arranged in a forked, spathe-like bract or between two opposite bracts. They are usually irregular, though in some case they may be slightly irregular, and either bisexual or unisexual. The perianth segments are in 1 or 2 series of 2–3 free segments; the inner series when present are usually showy and petal-like. Stamens 1–numerous, in 1 or more series; the inner ones sometimes sterile. pollen grains are globular and free but in the marine genera (Thalassia and Halophila) – the pollen grains are carried in chains, like strings of beads. The ovary is inferior with 2–15 united carpels containing a single locule with numerous ovules on parietal placentas which either protrude nearly to the centre of the ovary or are incompletely developed. Fruits are globular to linear, dry or pulpy, dehiscent or more usually indehiscent and opening by decay of the pericarp. Seeds are normally numerous with straight embryos and no endosperm.
Pollination can be extremely specialised.
The most recent phylogenetic treatment of the family recognizes four subfamilies. [3]
^ abAngiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III". Botanical Journal of the Linnean Society. 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. hdl:10654/18083.
^Christenhusz, M. J. M.; Byng, J. W. (2016). "The number of known plants species in the world and its annual increase". Phytotaxa. 261 (3). Magnolia Press: 201–217. doi:10.11646/phytotaxa.261.3.1.
^Les DH, DH; Moody, ML; Soros, CL (2006), "A reappraisal of phylogenetic relationships in the monocotyledon family Hydrocharitaceae (Alismatidae)", Aliso, 22: 211–230, doi:10.5642/aliso.20062201.18
^Tanaka, Norio; Setoguchi, Hiroaki; Murata, Jin (1997), "Phylogeny of the family Hydrocharitaceae inferred from rbcL and matK gene sequence data", Journal of Plant Research, 110 (3): 329, doi:10.1007/BF02524931, S2CID 10939773
^Les, DH; Cleland, MA; Waycott, M (1997), "Phylogenetic studies in Alismatidae, II: evolution of marine angiosperms (seagrasses) and hydrophily", Systematic Botany, 22 (3): 443, doi:10.2307/2419820, JSTOR 2419820
^Kubitzki (ed.) 1998. The families and genera of vascular plants, vol 4, Monocotyledons: Alismatanae and Commelinanae (except Gramineae). Springer-Verlag, Berlin.
hydrocharitaceae, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, december,. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Hydrocharitaceae news newspapers books scholar JSTOR December 2009 Learn how and when to remove this message Hydrocharitaceae is a flowering plant family including 16 known genera with a total of ca 135 known species Christenhusz amp Byng 2016 2 that including a number of species of aquatic plant for instance the tape grasses the well known Canadian waterweed and frogbit Hydrocharitaceae Common frogbit Hydrocharis morsus ranae Scientific classification Kingdom Plantae Clade Tracheophytes Clade Angiosperms Clade Monocots Order Alismatales Family HydrocharitaceaeJuss 1 Genera ApalantheAppertiellaBlyxaEgeriaElodeaEnhalusHalophilaHydrillaHydrocharisLagarosiphonLimnobiumMaideniaNajasNechamandraOtteliaStratiotesThalassiaVallisneria The family includes both freshwater and marine aquatics They are found throughout the world in a wide variety of habitats but are primarily tropical Contents 1 Description 2 Uses 3 Genera 4 References 5 External linksDescription editThe species are annual or perennial with a creeping monopodial rhizome with the leaves arranged in two vertical rows or an erect main shoot with roots at the base and spirally arranged or whorled leaves The leaves are simple and usually found submerged though they may be found floating or partially emerse As with many aquatics they can be quite variable in shape from linear to orbicular with or without a petiole and with or without a sheathing base The flowers are arranged in a forked spathe like bract or between two opposite bracts They are usually irregular though in some case they may be slightly irregular and either bisexual or unisexual The perianth segments are in 1 or 2 series of 2 3 free segments the inner series when present are usually showy and petal like Stamens 1 numerous in 1 or more series the inner ones sometimes sterile pollen grains are globular and free but in the marine genera Thalassia and Halophila the pollen grains are carried in chains like strings of beads The ovary is inferior with 2 15 united carpels containing a single locule with numerous ovules on parietal placentas which either protrude nearly to the centre of the ovary or are incompletely developed Fruits are globular to linear dry or pulpy dehiscent or more usually indehiscent and opening by decay of the pericarp Seeds are normally numerous with straight embryos and no endosperm Pollination can be extremely specialised The most recent phylogenetic treatment of the family recognizes four subfamilies 3 Subfamily Anacharioideae Appertiella Blyxa Egeria Elodea Lagarosiphon and Ottelia Subfamily Hydrilloideae Enhalus Halophila Hydrilla Maidenia Najas Nechamandra Thalassia and Vallisneria Subfamily Hydrocharitoideae Hydrocharis Limnobium Subfamily Stratiotoideae Stratiotes Hydrocharitaceae Hydrilloideae Enhalus Thalassia Halophila Vallisneria Nechamandra Hydrilla Najas Hydrocharitoideae Limnobium Hydrocharis Anacharioideae Elodea Egeria Appertiella Ottelia Blyxa Lagarosiphon Stratiotoideae Stratiotes nbsp Hydrilla verticillata nbsp Ottelia alismoidesUses editSome species have become established ornamental plants and subsequently serious weeds in the wild especially Egeria Elodea and Hydrilla Genera editApalanthe Appertiella Blyxa Egeria Elodea Enhalus Halophila Hydrilla Hydrocharis Lagarosiphon Limnobium Maidenia Najas 1 4 5 6 Nechamandra Ottelia Stratiotes Thalassia Vallisneria Genera crosses Hydrocharitaceae Kubitzki ed 1998 7 data kew 8 APWeb mobot org 9 Watson amp Dallwitz delta intkey 10 Hydrocharitaceae 1 Ottelia Ottelia Pers including Benedictaea Toledo Boottia Wall excludes Oligolobos Gagnep Ottelia Persoon including Benedictaea Toledo Boottia Wallich Oligolobos Gagnepain Xystrolobus Gagnepain Ottelia 2 Stratiotes Stratiotes L Stratiotes L Stratiotes 3 Hydrocharis Hydrocharis L Hydrocharis L Hydrocharis 4 Limnobium Limnobium Rich including Hydromystria G Mey Limnobium Richard including Hydromystria G Meyer Limnobium 5 Blyxa Blyxa Noronha ex Thouars excludes Enhydrias Ridl Blyxa Richard including Enhydrias Ridley Blyxa 6 Apalanthe Apalanthe Planch in Elodea Michaux Apalanthe 7 Egeria Egeria Planch Egeria Planchon Egeria 8 Elodea Elodea Michx including Anacharis Rich Udora Nutt Elodea Michaux including Anacharis Richard Apalanthe Planchon Hydora Besser Philotria Rafinesque Serpulica Pursh Udora Nuttall Elodea 9 Hydrilla Hydrilla Rich Hydrilla Richard Hydrilla 10 Appertiella Appertiella C D K Cook amp Triest Appertiella C D K Cook amp Triest Appertiella 11 Lagarosiphon Lagarosiphon Harv Lagarosiphon Harvey Lagarosiphon 12 Nechamandra Nechamandra Planch Nechamandra Planchon Nechamandra 13 Maidenia Maidenia Rendle Maidenia Rendle Maidenia 14 Vallisneria Vallisneria L Vallisneria L Vallisneria 15 Enhalus Enhalus Rich Enhalus Richard Enhalus 16 Thalassia Thalassia Banks ex C Koenig Thalassia C Koenig Thalassia 17 Halophila Halophila Thouars Halophila Thouars Halophila in Najas Najadaceae Najas L Najas L in Najas Najadaceae name not found Enhydrias Ridl in Blyxa Hydrocharitaceae name not found name not found Oligolobos Gagnep in Ottelia Hydrocharitaceae name not found Najadaceae 1 Najas in Najas Hydrocharitaceae in Najas Hydrocharitaceae NajasReferences edit a b Angiosperm Phylogeny Group 2009 An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants APG III Botanical Journal of the Linnean Society 161 2 105 121 doi 10 1111 j 1095 8339 2009 00996 x hdl 10654 18083 Christenhusz M J M Byng J W 2016 The number of known plants species in the world and its annual increase Phytotaxa 261 3 Magnolia Press 201 217 doi 10 11646 phytotaxa 261 3 1 Les DH DH Moody ML Soros CL 2006 A reappraisal of phylogenetic relationships in the monocotyledon family Hydrocharitaceae Alismatidae Aliso 22 211 230 doi 10 5642 aliso 20062201 18 Tanaka Norio Setoguchi Hiroaki Murata Jin 1997 Phylogeny of the family Hydrocharitaceae inferred from rbcL and matK gene sequence data Journal of Plant Research 110 3 329 doi 10 1007 BF02524931 S2CID 10939773 Les DH Cleland MA Waycott M 1997 Phylogenetic studies in Alismatidae II evolution of marine angiosperms seagrasses and hydrophily Systematic Botany 22 3 443 doi 10 2307 2419820 JSTOR 2419820 Genera of Hydrocharitaceae GRIN Taxonomy for Plants Kubitzki ed 1998 The families and genera of vascular plants vol 4 Monocotyledons Alismatanae and Commelinanae except Gramineae Springer Verlag Berlin Vascular Plant Families and Genera List of genera in family HYDROCHARITACEAE accessed 2016 06 02 http data kew org cgi bin vpfg1992 genlist pl HYDROCHARITACEAE VASCULAR PLANT FAMILIES and GENERA List of Genera in HYDROCHARITACEAE accessed 2016 06 02 http www mobot org mobot research apweb genera hydrocharitaceaegen html Watson amp Dallwitz Hydrocharitaceae The families of flowering plants http delta intkey com angio www hydrocha htm Archived 2009 04 08 at the Wayback MachineExternal links edit nbsp Media related to Hydrocharitaceae at Wikimedia Commons nbsp Data related to Hydrocharitaceae at Wikispecies Hydrocharideae Encyclopaedia Britannica Vol 14 11th ed 1911 p 112 Retrieved from https en wikipedia org w index php title Hydrocharitaceae amp oldid 1219234776, wikipedia, wiki, book, books, library,
