Elatine triandra

{{Short description|Species of flowering plant}}

{{Speciesbox

| image = Elatine_triandra_flower.jpg

| status = {{TNCStatus}}

| status_system = TNC

| status_ref = {{cite web |last1=NatureServe |title=Elatine triandra |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.161078/Elatine_triandra |access-date=26 March 2024 |location=Arlington, Virginia |date=2024}}

| taxon = Elatine triandra

| image_alt = Colour picture of Elatine triandra flower

| image_caption = Elatine triandra flower

| authority = Schkuhr.

}}

Elatine triandra is a species of flowering plant belonging to the family Elatinaceae.{{cite web |title=Elatine triandra Schkuhr {{!}} Plants of the World Online {{!}} Kew Science |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:89520-2 |website=Plants of the World Online |access-date=15 February 2021 |language=en}} It is known by the common name longstem waterwort.

Its native range is Temperate and Subtropical Old World to Western Malesia.

In New England, it's regarded as introduced and has been documented in both Massachusetts and Maine and it is found primarily around rivers.{{Cite web |title=Elatine triandra (Eurasian waterwort): Go Botany |url=https://gobotany.nativeplanttrust.org/species/elatine/triandra/ |access-date=2024-04-11 |website=gobotany.nativeplanttrust.org}}