Hydrosera

{{Short description|Genus of single-celled organisms}}

{{Use dmy dates|date=October 2023}}

{{Automatic taxobox

| image = Hydrosera Wallich, 1858.jpg

| taxon = Hydrosera

| authority = Wallich, 1858

| type_species = Hydrosera triquetra

| type_species_authority = Wallich, 1858

| subdivision = 11, see text

}}

Hydrosera is a genus of diatom described in 1858 by George Charles Wallich. Hydrosera exhibits valve margins resembling two superimposed triangles and the presence of a distinct rimoportula. Hydrosera also feature porefields at the three poles of one of the apparent triangles, which contain pseudocelli.{{Cite journal |title=Guide to Hydrosera |doi=10.1080/0269249X.2021.2006790 |journal= Diatom Research |date=2021 |author=Spaulding |volume=36 |issue=4 |pages=291–304 |pmid=35958044 |pmc=9359083 |url=https://diatoms.org/genera/hydrosera/guide|access-date=15 August 2023}} Dead Hydrosera create siliceous oozes.{{Cite web |title=Hydrosera G. C. Wallich 1858 |website= eol.org |url=https://eol.org/pages/92400|access-date=28 September 2023}}

Hydrosera grows in the streams of southern coastal areas and tropical islands.