Planera aquatica

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids I
Ordoo: Rosales

Familia: Ulmaceae
Genus: Planera
Species: Planera aquatica
Name

Planera aquatica (Walter) J.F.Gmel., 1791
References

Systema naturae, sive regna tria naturae systematice proposita per classes... 2(1):150. 1791
USDA, ARS, Germplasm Resources Information Network. Planera aquatica in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 09-Oct-10.

Planera is a genus of flowering plants with a single species, Planera aquatica,[2] the planertree[3] or water elm. Found in the southeastern United States, it is a small deciduous tree 10–15 m tall, closely related to the elms but with a softly, prickly nut 10–15 mm 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.[4]

Leaves: alternate, 3–7 cm long, with irregularly serrated to double serrated margins. Leaf base wedge-shaped or rounded. Leaf base often equal and symmetrical, but can be asymmetrical.[5] Thin pubescent hair is often present on underside of leaf.
Bark: gray-brown, thin, some flaky loose scales. Exfoliates to reveal red-brown area under bark.[5][6]
Fruit: a drupe. Has a green shell that turns brown with age. Matures April - May.[5]

Distinguishing Characteristics

While often confused with true elms, it can be easily distinguished by noticing the fruit are drupes and not samaras. When fruit are not in season, the flaky bark is unique to water elm and not characteristic of true elms.[5]

May also be confused with Celtis (hackberries), but hackberry leaves have pronounced lower lateral veins not found on water elm.[5]
Ecology

Typically found on alluvial floodplains subjected to seasonal or temporary flooding.[5] Often found in swamps, streams, lakes, or in riparian areas. Has some wildlife value, food for bees and some bird species. Prefers sandy or gravelly, moist soils.[6]

Classified as an obligate wetland plant (OBL).[3]

References

IUCN SSC Global Tree Specialist Group.; Botanic Gardens Conservation International; et al. (BGCI) (2020). "Planera aquatica". IUCN Red List of Threatened Species. 2020: e.T152858603A152905699. doi:10.2305/IUCN.UK.2020-1.RLTS.T152858603A152905699.en. Retrieved 19 November 2021.
"Search results for Planera". The Plant List. Retrieved 1 March 2016.
USDA, NRCS (n.d.). "Planera aquatica". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 7 October 2015.
"Water Elm Ulmaceae Planera aquatica J.F. Gmel". Virginia Tech Department of Forestry and Environmental Conservation. Retrieved December 15, 2014.
Kirkman, L. Katherine. (2007). Native trees of the Southeast. Brown, Claud L., 1925-, Leopold, Donald Joseph, 1956-. Portland, Or.: Timber Press. ISBN 978-0-88192-828-0. OCLC 69792028.
"Planera aquatica (Water Elm) | North Carolina Extension Gardener Plant Toolbox". plants.ces.ncsu.edu. Retrieved 2020-11-02.