The names of phyla and classes of blue-green algae (cyanobacteria, cyanophytes) and a typified name: Cyanobacteriophyta Oren, Mareš et Rippka

The naming of organisms long known as "blue-green algae" or "cyanophytes", and more recently as "cyanobacteria", is currently governed by both the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN) and the International Code of Nomenclature of Prokaryotes (ICNP) and a reciprocal principle of code coordination has been agreed so that names validated in either code are treated as valid in the other code. Under the ICN, both descriptive and typified names above the level of family are permitted, and the principle of priority does not apply but there is a recommendation that priority be applied to typified names. The current names in use, along with the typified or descriptive phylum/division names, and class names applied to cyanophytes, are discussed, and recommendations for their use are provided. We recommend adoption of the typified phylum name Cyanobacteriophyta Oren, Mare et Rippka, 2022 in papers employing the ICN and Chroococcophyceae Hollerbach, Kosinskaya et Poljansky, 1953 as a class name that includes all cyanobacteria as currently conceived but with the caveat that further class names may come into use in the future.