Simplify the following text for a Grade 12 native English-speaking person.
Original: Though the prokaryotic cyanobacteria ( commonly referred to as blue-green algae ) were traditionally included as `` algae '' in older textbooks , many modern sources regard this as outdated as they are now considered to be bacteria .
Simplified: Though the prokaryotic Cyanobacteria ( formerly referred to as blue-green algae ) were included as `` Algae '' in older textbooks , this is outdated .