North American Diatom Symposium1

Diatoms of North America provides analysts, academics and managers with tools for diatom taxonomy, nomenclature and ecology

North American Diatom Symposium2

Federal, tribal, state and local agencies use Diatoms of North America to monitor water quality and comply with the Clean Water Act

North American Diatom Symposium3

We aim to create a comprehensive diatom flora, accessible to everyone

North American Diatom Symposium4

Over 160 contributing taxonomists, from students-in-training to seasoned professionals, collaborate in producing an ambitious flora

Become a taxon contributor Learn more

Diatoms of North America is a collaborative work in progress, growing and changing as science advances.

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Taxon Contributors

Contributors produce comprehensive documentation on diatoms, leading to consistent and correct taxonomy.

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Taxa by Morphology

New to diatoms? Jump into diatom identification using the visual key.

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Editorial Review Board

Using diatoms in assessment? Specify the use of Diatoms of North America in contracts and task agreements.

What are Diatoms?


Diatoms are single-celled algae that live nearly everywhere there is water - streams, ponds, lakes, oceans, and even soils.

For practitioners

Identification Guide



Classification information, citations, links and species listings for 179 genera completed to date.



Identification guides, original descriptions, citations, autecological information and more for 1046 species and growing.


We encourage new contributors to submit taxon pages.

This project depends on many people to document the diverse diatom flora of streams, rivers, wetlands, lakes, springs, soils, estuaries and coastal zones.

Recent News & Projects

Diatom Web Academy 2022

Announcing the fall series... Sessions are recorded and can be accessed for later viewing. You are invited to join us, wherever you may be, from...

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Diatoms of North America has been developed in part with the generous funding and support of US EPA, USGS, the Institute of Arctic and Alpine Research at University of Colorado Boulder and other organizations.

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