| Hydrocharitaceae | |
|---|---|
 | |
| Common frogbit,Hydrocharis morsus-ranae | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Order: | Alismatales |
| Family: | Hydrocharitaceae Juss.[1] |
| Genera[2] | |
| |
| Synonyms[2] | |
NajadaceaeJuss. | |
Hydrocharitaceae is aflowering plant family which includes 14 accepted genera[2] and a total of ca 135 known species (Christenhusz & Byng 2016[3]). The family holds a number of species ofaquatic plants, includingtape-grass, the well-knownCanadian waterweed, andfrogbit.
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 areannual orperennial, with a creeping monopodialrhizome with theleaves arranged in two vertical rows, or an erect main shoot withroots at the base and spirally arranged or whorled leaves. The leaves are simple and usually found submerged, though they may be found floating or partiallyemerse. As with many aquatics they can be quite variable in shape – fromlinear toorbicular, with or without apetiole, and with or without a sheathing base.
Theflowers are arranged in a forked, spathe-likebract or between two opposite bracts. They are usually irregular, though in some case they may be slightly irregular, and either bisexual or unisexual. Theperianth 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 andHalophila) – the pollen grains are carried in chains, like strings of beads. Theovary is inferior with 2–15 unitedcarpels containing a singlelocule with numerous ovules onparietal 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 thepericarp.Seeds are normally numerous with straightembryos and noendosperm.
Pollination can be extremely specialised.
The most recent phylogenetic treatment of the family recognizes foursubfamilies.[4]
| Hydrocharitaceae | |
Some species have become establishedornamental plants, and subsequently serious weeds in the wild (especiallyEgeria,Elodea andHydrilla).
14 genera are currently accepted.[2]
| Kubitzki (ed. 1998[8]) | data.kew[9] | APWeb (mobot.org)[10] | Watson & Dallwitz (delta-intkey)[11] |
|---|---|---|---|
| Hydrocharitaceae | |||
| 1.Ottelia | Ottelia Pers. (includingBeneditaea Toledo,Boottia Wall.) (excludesOligolobos Gagnep.) | Ottelia Persoon (includingBeneditaea Toledo,Boottia Wallich,Oligolobos Gagnepain,Xystrolobos Gagnepain) | Ottelia |
| 2.Stratiotes | Stratiotes L. | Stratiotes L. | Stratiotes |
| 3.Hydrocharis | Hydrocharis L. | Hydrocharis L. | Hydrocharis |
| 4.Limnobium | Limnobium Rich. (includingHydromystria G.Mey. | Limnobium Richard (includingHydromystria G. Meyer) | Limnobium |
| 5.Blyxa | Blyxa Noronha ex Thouars (excludesEnhydrias Ridl.) | Blyxa Richard (includingEnhydrias Ridley) | Blyxa |
| 6.Apalanthe | Apalanthe Planch. | (inElodea Michaux) | Apalanthe |
| 7.Egeria | Egeria Planch. | Egeria Planchon | Egeria |
| 8.Elodea | Elodea Michx. (includingAnacharis Rich.,Udora Nutt.) | Elodea Michaux (includingAnacharis Richard,Apalanthe Planchon,Hydora Besser,Philotria Rafinesque,Serpicula Pursh,Udora Nuttall) | Elodea |
| 9.Hydrilla | Hydrilla Rich. | Hydrilla Richard | Hydrilla |
| 10.Appertiella | Appertiella C.D.K.Cook & Triest | Appertiella C. D. K. Cook & 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 |
| (inNajas, Najadaceae) | Najas L. | Najas L. | (inNajas, Najadaceae) |
| (name not found) | Enhydrias Ridl. | (inBlyxa, Hydrocharitaceae) | (name not found) |
| (name not found) | Oligolobos Gagnep. | (inOttelia, Hydrocharitaceae) | (name not found) |
| Najadaceae | |||
| 1.Najas | (inNajas, Hydrocharitaceae) | (inNajas, Hydrocharitaceae) | Najas |
Media related toHydrocharitaceae at Wikimedia Commons
Data related toHydrocharitaceae at Wikispecies| National | |
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| Other | |
