cyanobacteria

This term describes a specific group of photosynthetic prokaryotes often referred to as blue-green algae, though they are taxonomically bacteria. In scientific discourse, the word carries a neutral biological connotation, but in environmental contexts, it frequently evokes negative imagery associated with toxic blooms and water contamination.

Grammatically, this noun is a plural form derived from the Latin and Greek roots. Because it is the plural of cyanobacterium, it is treated as a plural noun in English; it does not take an additional s to form a plural and requires plural verb agreement (e.g., cyanobacteria are, not cyanobacteria is).