Carex firma was first described by Nicolaus Thomas Host in 1797, in his work Synopsis Plantarum in Austria provinciisque adjacentibus sponte crescentium.
Carex | Carex sylvatica | Carex nigra | Void Terra Firma | Carex lyngbyei | Carex leporina | Carex geyeri | Carex flacca | Carex echinata | The fungus forms ectomycorrhiza-like structures with the sedge ''Carex flacca | Carex utriculata | Carex rossii | Carex pilulifera | Carex otrubae | Carex inops | Carex emoryi | ''Carex binervis'' in its typical habitat, growing among ''Calluna |