Rhaphidorrhynchiumnigricaule is the name of a species, part of the genus Rhaphidorrhynchium.
This name is an alternative combination by Broth. of an original description of species by Brid. under the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN / commonly called the botany code)..
Hypnumnigricaule Brid.Hypnumnigricaule is the combination used by Brid. in the original description of the species.