Phaestoglochin, but hybrids have been reported between C. spicata and C. otrubae, and between C. spicata and C. echinata.
Carex | Carex sylvatica | Carex nigra | 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 |