Algae
Though the prokaryotic cyanobacteria (formerly referred to as blue-green algae) were included as "algae" in older textbooks, it is not now. The term algae is now used for eukaryotic organisms. All true algae have a nucleus within a membrane and chloroplasts inside one or more membranes. Algae are not a monophyletic group, as they do not all descend from a common algal ancestor.