Editing Azolla (section)

{{Short description|Genus of aquatic plants}}
{{Use mdy dates|date=November 2022}}
{{Automatic taxobox
| fossil_range = {{fossil range|Maastrichtian|Recent|[[Maastrichtian]]-[[Holocene]]}}
| image = Azolla caroliniana0.jpg
| image_caption = ''Azolla caroliniana''
| taxon = Azolla
| authority = [[Jean-Baptiste Lamarck|Lam.]]<ref name=trop1>In: ''Encyclopédie Méthodique, Botanique'' 1(1): 343. 1783. {{cite web |url=http://www.tropicos.org/Name/40023609 |title=Name - ''Azolla'' Lam. |quote=Annotation: a sp. nov. reference for ''Azolla filiculoides''<br />Type Specimens [[Holotype|HT]]: ''Azolla filiculoides'' |work=Tropicos |publisher=[[Missouri Botanical Garden]] |location=[[Saint Louis, Missouri]] |access-date=February 19, 2010}}</ref>
| type_species = ''[[Azolla filiculoides]]''<ref name=trop1/>
| type_species_authority = [[Jean-Baptiste Lamarck|Lam.]]
| subdivision_ranks = Species
| subdivision = See text
| synonyms =
* ''Carpanthus'' <small>Rafinesque</small>
* ''Rhizosperma'' <small>Meyen</small>
}}

'''''Azolla''''' (common called '''mosquito fern''', '''water fern''', and '''fairy moss''') is a [[genus]] of seven species of [[aquatic plant|aquatic]] [[fern]]s in the family [[Salviniaceae]]. They are extremely reduced in form and specialized, having a significantly different appearance to other ferns and more resembling some [[moss]]es or even [[Lemnoideae|duckweeds]]. ''[[Azolla filiculoides]]'' is one of two fern species for which a reference genome has been published.<ref>{{cite journal |last1=Li |first1=Fay-Wei |last2=Brouwer |first2=Paul |last3=Carretero-Paulet |first3=Lorenzo |last4=Cheng |first4=Shifeng |last5=de Vries |first5=Jan |last6=Delaux |first6=Pierre-Marc |last7=Eily |first7=Ariana |last8=Koppers |first8=Nils |last9=Kuo |first9=Li-Yaung |date=2018-07-02 |title=Fern genomes elucidate land plant evolution and cyanobacterial symbioses |journal=Nature Plants |volume=4 |issue=7 |pages=460–472 |language=En |doi=10.1038/s41477-018-0188-8 |pmid=29967517 |pmc=6786969 |issn=2055-0278}}</ref> It is believed that this genus grew so prolifically during the [[Eocene]] (and thus absorbed such a large amount of carbon) that it triggered a global cooling event that has lasted to the present.<ref name="Speelman-2009">{{cite journal |last1=Speelman |first1=E. N. |last2=Van Kempen |first2=M. M. L. |last3=Barke |first3=J. |last4=Brinkhuis |first4=H. |last5=Reichart |first5=G. J. |last6=Smolders |first6=A. J. P. |last7=Roelofs |first7=J. G. M. |last8=Sangiorgi |first8=F. |last9=De Leeuw |first9=J. W. |last10=Lotter |first10=A. F. |last11=Sinninghe Damsté |first11=J. S. |date=March 2009 |title=The Eocene Arctic Azolla bloom: environmental conditions, productivity and carbon drawdown |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1472-4669.2009.00195.x |journal=Geobiology |language=en |volume=7 |issue=2 |pages=155–170 |doi=10.1111/j.1472-4669.2009.00195.x|pmid=19323694 |bibcode=2009Gbio....7..155S |s2cid=13206343 |url-access=subscription }}</ref>

''Azolla'' may establish as an [[invasive plant]] in areas where it is not native. In such a situation, it can alter [[aquatic ecosystem]]s and [[biodiversity]] substantially.{{Why|date=May 2025|reason=What exactly causes this?}}<ref name="Weber-2017">{{cite book |last1=Weber |first1=Ewald |title=Invasive Plant Species of the World: A Reference Guide to Environmental Weeds |date=2017 |page=65 |isbn=978-1-78064-386-1 |url=https://books.google.com/books?id=Ns_UDgAAQBAJ}}</ref>