Summary 2

Anabaena is a genus of filamentous cyanobacteria that may be found in phytoplankton assemblages or mixed with shoreline vegetation in lakes and ponds. It is known for its nitrogen fixing abilities; one species (Anabaena azollae, which was renamed Trichormus azollae) forms a symbiotic relationship with the mosquito fern (Azolla).

The taxonomy for Anabaena is currently in a state of flux and a newer genus name, Dolichospermum, is now used for most of the planktonic species, including many of the toxin-forming species. For more information on the Dolichospermum / Anabaena group please see:

About 3

This guide was prepared by Dr. Robin Matthews, the Director of the Institute for Watershed Studies ( and a professor of Environmental Sciences at Western Washington University ( In addition to this guide she has also written two ebooks (more on the way) on phytoplankton identification (see the "algae books" link on and an online key to the cyanobacteria (

Sources and Credits

  1. (c) Robin Matthews, some rights reserved (CC BY-NC-SA), uploaded by rmatth,
  2. Adapted by Bryan Milstead from a work by (c) Wikipedia, some rights reserved (CC BY-SA),
  3. (c) Bryan Milstead, some rights reserved (CC BY-NC-SA)

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