Orthocladalaxa is the name of a species, part of the genus Orthoclada.
This name is an alternative combination by P.Beauv. of an original description of species by Rich. under the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN / commonly called the botany code)..
Airalaxa Rich.Airalaxa is the combination used by Rich. in the original description of the species.