Stereocaulon paschale

Stereocaulon paschale is host to some lichenicolous fungi which infect various parts of the thallus. Most of these fungi have a Holarctic distribution. These fungi include:[3]

• Arthonia stereocaulina, Infects the phyllocladia but rarely causes disease.
• Catillaria stereocaulorum, Mainly infects the phyllocladia, which can become swollen and dark. It is common in the Arctic.
• Cercidospora stereocaulorum, Infects phyllocladia and sometimes on stems, cephalodia and apothecia.
• Endococcus nanellus, Infects phyllocladia and sometimes on stems, cephalodia and apothecia. Often found in discolored apothecia but does probably not cause the discoloration.
• Lasiosphaeriopsis stereocaulicola, Usually found at the stem base which can turn brown but no other symptoms are known.
• Lichenopeltella stereocaulorum, Most often found on stems. This species was only discovered in 2010.
• Opegrapha stereocaulicola, Infects stems which may become darker.
• Phaeosporobolus alpinus, Commensal. Most commonly found on species of Pertusaria or Ochrolechia.
• Polycoccum trypethelioides, Produces galls on stem which change colour with time turning cinnamon colour or brown.