Azolla rubra
{{Short description|Species of fern}}
{{Speciesbox
| image = Azolla rubra john barkla cc-by 02.jpg
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| genus = Azolla
| species = rubra
| authority = R.Br.
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Azolla rubra, known commonly as red azolla and Pacific azolla, is a species of aquatic fern native to Australia and New Zealand.{{Cite web|url=https://blog.tepapa.govt.nz/2012/11/29/help-with-floating-fern/|title=Help with floating fern|date=2012-11-29|website=Te Papa's Blog|access-date=2019-09-08}} In New Zealand, it is also known by its Māori names {{lang|mi|returetu}}, {{lang|mi|roturotu}}, {{lang|mi|kārearea}} and {{lang|mi|kārerarera}}.{{cn|date=June 2020}}
Distribution
Azolla rubra is found in Australia and New Zealand. Its range is thought to extend to Papua New Guinea, Indonesia and Japan.{{Cite web|url=http://www.nzflora.info/factsheet/taxon/Azolla-rubra.html|title=Flora of New Zealand {{!}} Taxon Profile {{!}} Azolla rubra|website=www.nzflora.info|access-date=2019-09-08}}{{Cite journal|last=Reid|first=Jill D.|last2=Plunkett|first2=Gregory M.|last3=Peters|first3=Gerald A.|date=May 2006|title=Phylogenetic Relationships in the Heterosporous Fern Genus Azolla (Azollaceae) Based on DNA Sequence Data from Three Noncoding Regions|journal=International Journal of Plant Sciences|volume=167|issue=3|pages=529–538|doi=10.1086/501071|issn=1058-5893}}
In New Zealand, it is found on the North and South Islands, and on Raoul Island in the Kermadecs.{{Cite web|url=http://www.nzpcn.org.nz/flora_details.aspx?ID=2065|title=Azolla rubra {{!}} New Zealand Plant Conservation Network|website=www.nzpcn.org.nz|access-date=2019-09-08}}
Habitat
Forms extensive red mats on slow moving bodies of water such as streams, lakes, ponds and swamps. May also occur on man-made water bodies such as farm ponds, drains, ditches, dams and cattle troughs.