Although cyanobacteria are often referred to as "blue-green algae", most authorities exclude all prokaryotes, including cyanobacteria, from the definition of algae.
ɔːlðˈoʊ sˌaɪɐnˌɑːbɐktˈɪɹiə ɑːɹ ˈɔfən ɹᵻfˈɜːd tʊ æz "blˈuːɡɹˈiːn ˈælɡiː", mˈoʊst ɐθˈɔːɹɪɾiz ɛksklˈuːd ˈɔːl pɹˈɑːkɐɹɪˌoʊts, ɪŋklˈuːdɪŋ sˌaɪɐnˌɑːbɐktˈɪɹiə, fɹʌmðə dˌɛfɪnˈɪʃən ʌv ˈælɡiː.