Planera
{{Short description|Genus of flowering plants}}
{{Automatic taxobox
|image = NAS-130y Planera aquatica.png
|image_caption = Planera aquatica
|taxon = Planera
|authority = J.F.Gmel.
|subdivision_ranks = Species
|subdivision = See text
|range_map =
|range_map_caption =
}}
Planera is a genus of flowering plants with a single living species, Planera aquatica,{{cite web |title=Search results for Planera|work=The Plant List |url=http://www.theplantlist.org/tpl1.1/search?q=Planera |accessdate=1 March 2016 }} the planertree{{PLANTS|id=PLAQ|taxon=Planera aquatica|accessdate=7 October 2015}} or water elm. The genus has an extensive fossil record dating back to the Cretaceous and spanning the northern hemisphere, with a few southern hemisphere records as well.{{cite web |url=http://ifpni.org/genus.htm?id=451A98E2-0298-493C-8B99-A37EC66EB5A1 |website=The International Fossil Plant Names Index |title=Planera |accessdate=8 Feb 2023}} The living species is found in the southeastern United States, it is a small deciduous tree {{cvt|10–15|m|in}} tall, closely related to the elms but with a softly, prickly nut {{cvt|10–15|mm|in}} diameter, instead of a winged seed. It grows, as the name suggests, on wet sites. Despite its common English name, this species is not a true elm, although it is a close relative of the elms (species of the genus Ulmus). It is also subject to Dutch elm disease, a disease which affects only members of the Ulmaceae. It is native to most of the southeast United States. It is hardy down to Zone 7.{{cite web|url=http://dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=347|title=Water Elm Ulmaceae Planera aquatica J.F. Gmel.|publisher=Virginia Tech Department of Forestry and Environmental Conservation|accessdate=December 15, 2014}}
Species
=Fossil species=
{{div col}}
- †Planera antiqua {{small|Heer, 1883}} (Santonian-Campanian; Paatuut Formation, Greenland)
- †Planera aquaticiformis {{small|Hollick, 1936}} (Paleocene/Eocene; "Berg Lake flora", Alaska)
- †Planera australis {{small|Ettingshausen, 1887}} (Late Cretaceous; Otago, New Zealand)
- †Planera chankaensis {{small|Pavlyutkin, 2005}} (Miocene; Novokachalinsk, Russia)
- †Planera crenata {{small|Newberry, 1883}} (jr homonym, replacement name P. lingualis)
- †Planera cretacea {{small|Berry, 1907}} (Cretaceous; North Carolina)
- †Planera dubia {{small|Lesquereux, 1859}} (Eocene, Chuckanut Formation, Washington)
- †Planera emarginata {{small|(Göppert) Heer, 1856}} (Tortonian, Poland)
- †Planera ezoana {{small|Ôishi & Huzioka, 1954}} (Eocene; Hokkaido, Japan)
- †Planera hebridica {{small|Simpson, 1961}} ("Cenozoic"; Isle of Mull, Scotland)
- †Planera knowltoniana {{small|Newberry, 1896}} (Cenomanian; Raritan Formation, Virginia)
- †Planera mullensis {{small|Simpson, 1961}} ("Cenozoic"; Isle of Mull, Scotland)
- †Planera myricifolia {{small|(Lesquereux) Cockerell, 1908}} (Priabonian; Florissant Formation, Colorado)
- †Planera parvula {{small|Saporta, 1888}} (Oligocene; France)
- †Planera subkeaki {{small|(Rérolle) Saporta, 1888}} (Tortonian; La Cerdagnya, France)
- †Planera thompsoniana {{small|Traverse, 1955}} (Burdigalian; Brandon lignite, Vermont)
- †Planera ulmifolia {{small|Schloemer-Jäger, 1958}} (Paleocene; Brøgger peninsula, Spitsbergen)
- †Planera variabilis {{small|Newberry, 1883}} (Ypresian; Green River Formation, Wyoming)
{{div col end}}
=Species formerly included in ''Planera''=
- †Abelicea ungeri {{small|(Kováts ex Ettingshausen) Holmboe}}
- †Cedrelospermum nervosum {{small|(Newberry) Manchester}}
- †Chaetoptelea microphylla {{small|(Newberry) Hickey}}
- †Fagopsis longifolia {{small|Lesquereux}}