Editing Alismatales

{{Short description|Order of herbaceous flowering plants of marshy and aquatic habitats}}
{{Use dmy dates|date=September 2021}}
{{Automatic taxobox
|image = AlismaPlant1.jpg
|image_caption = ''[[Alisma plantago-aquatica]]''
|taxon = Alismatales
|authority = [[Robert Brown (Scottish botanist from Montrose)|R.Br.]] ''ex'' [[Friedrich von Berchtold|Bercht.]] & [[Jan Svatopluk Presl|J.Presl]]<ref name="apgiii">{{Citation |last=Angiosperm Phylogeny Group |year=2009 |title=An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III |journal=Botanical Journal of the Linnean Society |volume=161 |issue=2 |pages=105–121 |doi=10.1111/j.1095-8339.2009.00996.x |doi-access=free |hdl=10654/18083 |hdl-access=free }}</ref>
|subdivision_ranks = Families
|subdivision = ''See [[#Taxonomy|Taxonomy]]''
}}
[[File:044 Dracunculus vulgaris at Akrotiri peninsula, Crete, Greece.jpg|thumb|220px|Snake lily (''[[Dracunculus vulgaris]]'') of family [[Araceae]] in [[Crete]], [[Greece]].]]
[[File:Ottelia alismoides W IMG 0915.jpg|thumb|220px|''[[Ottelia alismoides]]'' from family [[Hydrocharitaceae]] in [[Hyderabad]], India.]]

The '''Alismatales''' ('''alismatids''') are an order of [[flowering plant]]s including about 4,500 species. Plants assigned to this order are mostly [[Tropical vegetation|tropical]] or [[Aquatic plant|aquatic]]. Some grow in [[fresh water]], some in [[marine habitats]]. Perhaps the most important food crop in the order is the [[taro]] plant, ''Colocasia esculenta''.

==Description==
The Alismatales comprise [[herbaceous]] flowering plants of often aquatic and marshy habitats, and the only monocots known to have green [[Plant embryonic development|embryo]]s other than the [[Amaryllidaceae]]. They also include the only marine angiosperms growing completely submerged, the [[seagrass]]es.<ref name=Stevens>{{cite web|last=Stevens | first=P.F. | year=2022 | version=14 | access-date= 28 October 2022 | title=Alismatales|url=http://www.mobot.org/MOBOT/Research/APweb/orders/alismatalesweb.htm#Alismatales|website=[[Angiosperm Phylogeny Website]]|publisher=[[Missouri Botanical Garden]]}}</ref> The [[flower]]s are usually arranged in [[inflorescence]]s, and the mature seeds lack [[endosperm]].

Both marine and freshwater forms include those with staminate flowers that detach from the parent plant and float to the surface. There they can pollinate carpellate flowers floating on the surface via long pedicels.<ref name=SullTitu96>{{Citation |mode=cs1 |last1=Sullivan |first1=G. |last2=Titus |first2=J.E. |date=1996 |title=Physical site characteristics limit pollination and fruit set in the dioecious hydrophilous species, ''Vallisneria americana'' |journal=Oecologia |volume=108 |issue=2 |pages=285–292 |doi=10.1007/BF00334653 |pmid=28307841 |bibcode=1996Oecol.108..285S |s2cid=13369438 |name-list-style=amp }}</ref> In others, pollination occurs underwater, where pollen may form elongated strands, increasing chance of success. Most aquatic species have a totally submerged juvenile phase, and flowers are either floating or emerge above the water's surface. Vegetation may be totally submersed, have floating leaves, or protrude from the water. Collectively, they are commonly known as "water plantain".<ref>{{Cite web |url=http://www.eeb.uconn.edu/people/les/Manuscript_Files/Encyclopedia_Life_Sciences.pdf |title=-Alismatales (Water Plantains) |access-date=27 May 2010 |archive-url=https://web.archive.org/web/20100612013757/http://www.eeb.uconn.edu/people/les/Manuscript_Files/Encyclopedia_Life_Sciences.pdf |archive-date=12 June 2010 |url-status=dead }}</ref>

==Taxonomy==
The Alismatales contain about 165 genera in 13 families, with a [[cosmopolitan distribution]]. [[Phylogenetically]], they are [[basal monocot]]s, diverging early in evolution relative to the [[lilioid]] and [[commelinid]] [[monocot]] lineages.{{sfn|Wilkin|Mayo|2013}} Together with the [[Acorales]], the Alismatales are referred to informally as the alismatid monocots.{{sfn|RBG|2010}}

===Early systems===
The [[Cronquist system]] (1981) places the Alismatales in subclass [[Alismatidae]], class [[Liliopsida]] [= monocotyledons] and includes only three families as shown:
* [[Alismataceae]]
* [[Butomaceae]]
* [[Limnocharitaceae]]
Cronquist's subclass Alismatidae conformed fairly closely to the order Alismatales as defined by APG, minus the Araceae.

The [[Dahlgren system]] places the Alismatales in the superorder [[Alismatanae]] in the subclass [[Liliidae]] [= monocotyledons] in the class [[Magnoliopsida]] [= angiosperms] with the following families included:
*  [[Alismataceae]]
*  [[Aponogetonaceae]]
*  [[Butomaceae]]
*  [[Hydrocharitaceae]]
*  [[Limnocharitaceae]]

In Tahktajan's classification (1997), the order Alismatales contains only the Alismataceae and Limnocharitaceae, making it equivalent to the Alismataceae as revised in APG-III. Other families included in the Alismatates as currently defined are here distributed among 10 additional orders, all of which are assigned, with the following exception, to the Subclass Alismatidae. Araceae in Tahktajan 1997 is assigned to the [[Arales]] and placed in the Subclass Aridae; Tofieldiaceae to the [[Melanthiales]] and placed in the [[Liliidae]].<ref>{{cite web| url = http://botany.csdl.tamu.edu/FLORA/newgate/cronang.htm| title = -Flowering Plant Gateway| access-date = 27 May 2010| archive-date = 6 October 2011| archive-url = https://web.archive.org/web/20111006041129/http://botany.csdl.tamu.edu/FLORA/newgate/cronang.htm| url-status = dead}}</ref>

===Angiosperm Phylogeny Group===
The Angiosperm Phylogeny Group system ([[APG system|APG]]) of 1998 and [[APG II system|APG II]] (2003) assigned the Alismatales to the monocots, which may be thought of as an unranked clade containing the families listed below. The biggest departure from [[list of systems of plant taxonomy|earlier systems]] (see below) is the inclusion of family Araceae. By its inclusion, the order has grown enormously in number of species. The family Araceae alone accounts for about a hundred genera, totaling over two thousand species. The rest of the families together contain only about five hundred species, many of which are in very small families.{{sfn|APG IV|2016}}

The [[APG III system]] (2009) differs only in that the [[Limnocharitaceae]] are combined with the Alismataceae; it was also suggested that the genus ''[[Maundia]]'' (of the [[Juncaginaceae]]) could be separated into a monogeneric family, the [[Maundiaceae]], but the authors noted that more study was necessary before the Maundiaceae could be recognized.<ref name="apgiii" />

* order Alismatales ''[[sensu]]'' APG III
*: family [[Alismataceae]] (''including'' [[Limnocharitaceae]])
*: family [[Aponogetonaceae]]
*: family [[Araceae]]
*: family [[Butomus|Butomaceae]] <!-- monogeneric family -->
*: family [[Cymodoceaceae]]
*: family [[Hydrocharitaceae]]
*: family [[Juncaginaceae]]
*: family [[Posidoniaceae]]
*: family [[Potamogetonaceae]]
*: family [[Ruppiaceae]]
*: family [[Scheuchzeriaceae]]
*: family [[Tofieldiaceae]]
*: family [[Zosteraceae]]

In [[APG IV]] (2016), it was decided that evidence was sufficient to elevate ''Maundia'' to family level as the [[monogeneric]] Maundiaceae.{{sfn|APG IV|2016}} The authors considered including a number of the smaller orders within the Juncaginaceae, but an online survey of botanists and other users found little support for this "[[lumping]]" approach.{{sfnp|ps=none|Christenhusz|Vorontsova|Fay|Chase|2015}} Consequently, the family structure for APG IV is:

{{cladogram
|title=Cladogram of Alismatales<ref name=Stevens />
|{{clade|style=font-size:80%;line-height:100%;width:300px;
|label1='''Alismatales'''
|1={{clade
  |1=[[Araceae]]
  |2={{clade
    |1=[[Tofieldiaceae]]
    |2={{clade
      |1={{clade
        |1=[[Alismataceae]]
        |2={{clade
          |1=[[Butomaceae]]
          |2=[[Hydrocharitaceae]]
           }}
         }}
      |2={{clade
        |1=[[Aponogetonaceae]]
        |2={{clade
          |1=[[Scheuchzeriaceae]]
          |2={{clade
            |1=[[Juncaginaceae]]
            |2={{clade
              |1=[[Maundiaceae]]
              |2={{clade
                |1={{clade
                  |1=[[Potamogetonaceae]]
                  |2=[[Zosteraceae]]
                   }}
                |2={{clade
                  |1=[[Posidoniaceae]]
                  |2={{clade
                    |1=[[Cymodoceaceae]]
                    |2=[[Ruppiaceae]]
                     }}
                   }}
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
   }}
}}
}}

*: family [[Alismataceae]] (''including'' [[Limnocharitaceae]])
*: family [[Aponogetonaceae]]
*: family [[Araceae]]
*: family [[Butomus|Butomaceae]] <!-- monogeneric family -->
*: family [[Cymodoceaceae]]
*: family [[Hydrocharitaceae]]
*: family [[Juncaginaceae]]
*: family [[Maundiaceae]]
*: family [[Posidoniaceae]]
*: family [[Potamogetonaceae]]
*: family [[Ruppiaceae]]
*: family [[Scheuchzeriaceae]]
*: family [[Tofieldiaceae]]
*: family [[Zosteraceae]]

=== Phylogeny ===
[[Cladogram]] showing the orders of monocots ([[Lilianae]] ''[[sensu]]'' Chase & Reveal){{sfn|Chase|Reveal|2009}} based on molecular phylogenetic evidence:

{{barlabel|size=12|at1=5|label1=[[Lilioid monocots]] |bar1=purple|at2=0.5|label2=Alismatid monocots|bar2=green|style=font-size:100%;line-height:125%;width:400px;|cladogram=
{{clade
|align=center
|label1= [[Lilianae]] ''sensu'' Chase & Reveal{{sfn|Chase|Reveal|2009}} 
|1={{clade
    | 1={{clade|thickness=3
      | 1=[[Acorales]]|barbegin1=green
      | 2={{clade|thickness=3
        |label1=
        | 1= '''Alismatales''' |barend1=green
        | 2={{clade
          | 1=[[Petrosaviales]] |barbegin1=purple
          |2={{clade
            |1={{clade
              |1=[[Dioscoreales]]|bar1=purple
              |2=[[Pandanales]] |bar2=purple
                }}
            | 2={{clade
              |1=[[Liliales]] |bar1=purple
              |2={{clade
                |1=[[Asparagales]] |barend1=purple
                |label2=[[commelinids]]
                |2={{clade
                  |1=[[Dasypogonaceae]]
                  |2=[[Arecales]]
                  |3=[[Poales]]
                  |4={{clade
                    |1=[[Zingiberales]]
                    |2=[[Commelinales]]
                     }}
                   }}
                 }}
               }}
             }}
           }}
         }}
       }}
     }}
}}
}}

{{clear}}

== References ==
{{Reflist|2}}

== Further reading ==
{{Refbegin|30em}}
* [[Barthélemy Charles Joseph du Mortier|B. C. J. du Mortier]] 1829. Analyse des Familles de Plantes : avec l'indication des principaux genres qui s'y rattachent. Imprimerie de J. Casterman, Tournay
* W. S. Judd, C. S. Campbell, E. A. Kellogg, P. F. Stevens, M. J. Donoghue, 2002. Plant Systematics: A Phylogenetic Approach, 2nd edition. Sinauer Associates, Sunderland, Massachusetts {{ISBN|0-87893-403-0}}.
* {{cite book|editor1-last=Wilkin|editor1-first=Paul|editor2-last=Mayo|editor2-first=Simon J|title=Early events in monocot evolution|url=https://books.google.com/books?id=sEfKwaRHQj4C|date=2013|publisher=Cambridge University Press|location=Cambridge|isbn=978-1-107-01276-9|access-date=9 December 2015}}
* {{Citation |last=Royal Botanic Gardens, Kew |author-link=Royal Botanic Gardens, Kew |title=Monocots I: General Alismatids & Lilioids |url=http://www.kew.org/science/directory/teams/MonocotsI/index.html |date=2016 |ref={{harvid|RBG|2010}} |access-date=26 January 2016 |archive-url=https://web.archive.org/web/20150914163722/http://www.kew.org/science/directory/teams/MonocotsI/index.html |archive-date=14 September 2015 |url-status=dead }}
* {{citation|last1=Chase|first1=Mark W|last2=Reveal|first2=James L|author-link1=Mark W Chase|author-link2=James L Reveal|title=A phylogenetic classification of the land plants to accompany APG III|journal=[[Botanical Journal of the Linnean Society]]|date=2009|volume=161|issue=2|pages=122–127|url=http://reflora.jbrj.gov.br/downloads/APG2.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://reflora.jbrj.gov.br/downloads/APG2.pdf |archive-date=2022-10-09 |url-status=live|doi=10.1111/j.1095-8339.2009.01002.x|doi-access=free}}
* {{cite book|last1=Les|first1=Donald H|last2=Tippery|first2=Nicholas P|title=In time and with water ... the systematics of alismatid monocotyledons|pages=118–164|url=http://hydrodictyon.eeb.uconn.edu/people/les/Manuscript_Files/Early_Events.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://hydrodictyon.eeb.uconn.edu/people/les/Manuscript_Files/Early_Events.pdf |archive-date=2022-10-09 |url-status=live}}, in {{harvtxt|Wilkin|Mayo|2013}}
* {{Cite journal |last=Angiosperm Phylogeny Group |author-link=Angiosperm Phylogeny Group|year=2016 |title=An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV |journal=[[Botanical Journal of the Linnean Society]] |volume=181 |issue=1 |pages=1–20 |doi=10.1111/boj.12385|ref={{harvid|APG IV|2016}} |doi-access=free }}
* {{citation |last1=Christenhusz|first1=Maarten J.M.|last2=Vorontsova|first2=Maria S.|author2-link=Maria Vorontsova (botanist)|last3=Fay|first3=Michael F.|last4=Chase|first4=Mark W.|author-link3=Michael Francis Fay|author-link4=Mark Chase|title=Results from an online survey of family delimitation in angiosperms and ferns: recommendations to the Angiosperm Phylogeny Group for thorny problems in plant classification|journal=[[Botanical Journal of the Linnean Society]]|date=August 2015|volume=178|issue=4|pages=501–528|doi=10.1111/boj.12285
|name-list-style=amp|doi-access=free}}
{{Refend}}

== External links ==
* {{Wikispecies-inline|Alismatales}}
* {{Commons category-inline|Alismatales}}

{{Monocotyledons}}
{{Taxonbar|from=Q27341}}
{{Authority control}}

[[Category:Alismatales| ]]
[[Category:Angiosperm orders]]