This is the common name for photosynthetic protists that occur in unicellular, colonial and multicellular form; many of their names are derived from the pigments that they carry in their cells.

This state is talking about Algae.

Indeed, the algae can be classified according to their pigmentation. In the broadest sense of the term, algae gather:

* Prokaryotic organisms: Cyanobacteria (formerly called "blue-green algae" or Cyanophyceae);

* Eukaryotes:

-various groups with unicellular species (Euglenophytes, Cryptophytes, Haptophytes, Glaucophytes, etc.),

-other groups with unicellular or multicellular species:

   "red algae" or Rhodophyta,

   Stramenopiles (including diatoms and "brown algae" or Phéophycées),

-and finally, plants quite close to terrestrial plants: "green algae", which include, among others, Ulvophyceae.