Zannichellia

{{Short description|Genus of flowering plants}} {{automatic taxobox | image = Zannichellia palustris detail.jpeg | image_caption = ''Zannichellia palustris'' | taxon = Zannichellia | authority = L. | synonyms = *''Aponogeton'' J.Hill, 1756 *''Pelta'' Dulac *''Pseudalthenia'' (Graebn.) Nakai *''Vleisia'' Toml. & Posl. | synonyms_ref = <ref name=GBIF>{{GBIF|id=2652929|taxon=''Zannichellia''|access-date=2022-11-06}}</ref> }}

'''''Zannichellia''''' (common name '''horned pondweed''')<ref name=RobertsonArber>{{cite book|last=Robertson Arber|first=Agnes|title= Water Plants; A Study of Aquatic Angiosperms|year=2008|publisher=Read Books|isbn=978-1-4086-5146-9}}</ref> is a genus of submerged aquatic flowering plant,<ref name=Tiner>{{cite book|last1=Tiner|first1=Ralph W. W.|others=Abigail Rorer (Illustrator)|title= Field guide to coastal wetland plants of the southeastern United States|year=1993|publisher=University of Massachusetts Press|isbn=978-0-87023-833-8}}</ref> with threadlike leaves and tiny flowers.<ref name=Tiner /> It is fully adapted to an aquatic life cycle, including underwater pollination.<ref name=RobertsonArber />

There are perhaps five species, including ''Zannichellia palustris''.<ref>{{Cite web|url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=135257|title=Zannichellia in Flora of North America @ efloras.org|website=www.efloras.org|access-date=2017-02-01}}</ref>

The genus is named after Gian Girolamo Zannichelli (1662–1729), Italian botanist.

== Description == These slender plants grow submerged in water. The leaves are usually oppositely arranged and long and narrow. They have stipular sheaths.<ref name="SAGenera">{{Cite book |last=Phillips |first=Edwin Percy |title=The genera of South African flowering plants |publisher=Government Printer |year=1951 |publication-place=South Africa}}</ref>

The flowers are unisexual. The male flowers have a single stamen with a slender filament and anthers that are 2-4-thecous.<ref name="SAGenera" />

The female flowers have a cup-shaped membranous perianth. There are usually four carpels with a single pendulous ovule in each ovary. The stigma is shield shaped with toothed margins.<ref name="SAGenera" />

The fruit is usually made of four long, dry achenes. The seeds are pendulous with a sub-cylindric embryo. The cotyledonous end is folded on itself twice.<ref name="SAGenera" />

== Distribution == The species of this genus are widely distributed and are found growing in temperate and tropical regions around the world.<ref name="SAGenera" /><ref name="GBIF" /> They grow in brackish and salt water.<ref name="SAGenera" />

==Selected species== The following species are accepted:<ref name = "GBIF" /> *''Zannichellia andina'' Holm-Niels. & R.R.Haynes *''Zannichellia aschersoniana'' Graebn. *''Zannichellia contorta'' (Desf.) Cham. *''Zannichellia indica'' Rottler ex Royle, 1840 *''Zannichellia obtusifolia'' Talavera, García-Mur. & H.Smit *''Zannichellia palustris'' L. *''Zannichellia pedicellata'' Buch.-Ham. ex Wall. *''Zannichellia peltata'' Bertol. *''Zannichellia tuberosa'' Lour.

== References == {{refbegin}} *{{cite web|last=Guiry|first=M.D.|last2=Guiry|first2=G.M.|year=2008|title=Zannichellia|work=AlgaeBase|publisher=World-wide electronic publication, National University of Ireland, Galway|url=https://www.algaebase.org/search/genus/detail/?genus_id=44019|access-date= 2009-02-21}} <references/> {{refend}}

Category:Potamogetonaceae Category:Alismatales genera