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Diatoms of the United States is now known as Diatoms of North America.
This site has been redesigned and updated, and will be closing soon.

Diatom identification guide & ecological resource

for water resource managers, ecologists, taxonomists, analysts, systematists, students, and the public.

VISIT us at


Diatoms of the United States has been revised and updated. This site will be closing soon.

Cymbella subturgidula


157 Completed
22 Underway
888 Completed
183 Underway
1071 TOTAL

Getting Started

About this website

What are diatoms?

Identify your taxa

Special News

26 June, 2015

Editorial Review Guidelines

25 March, 2011

Information for contributors


23 March, 2018

Standardization of taxon authorship names

13 February, 2018

Tiny fossils, huge slides

More news...


U.S. Geological Survey / Academy of Natural Sciences of Philadelphia

Diatoms from the Crown of the Continent

Atmospheric deposition of nitrogen and its effects on diatoms

More projects...