blue-green alga

• POS: Noun Phrase

CIDE DICTIONARY

blue-green alga,  [from the color and resemblance to algae.].

 any of a group of photosynthetic microorganisms possessing characteristics of both bacteria and plants. When classed as bacteria, they are assigned to the Cyanobacteria; when classed as plants, they are assigned to the Cyanophyta. They are now known to be prokaryotic, and are usually called cyanobacteria in technical contexts. See cyanobacterium.  [PJC]