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Diatoms of North America

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We aim to provide accurate information on diatom morphology, nomenclature, ecology, and geographic distribution.

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Our content is created by over 100 contributors, from students to expert taxonomists, guided by an Editorial Review Board.

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Join our live Diatom Web Academy series, or listen to recorded presentations.

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 164 genera completed to date.



Identification guides, original descriptions, citations, autecological information and more for 990 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

WEBINAR: The genus Navicula

Description: The genus Navicula is the largest genus within the diatoms, with over 900 species reported from freshwaters of North America....

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Diatom Web Academy 2021

The Diatom Web Academy continues... Sessions are recorded and can be accessed for later viewing. You are invited to join us, wherever you may be,...

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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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