''Stereocaulon paschale'' is a species of lichen belonging to the family

Stereocaulaceae The Stereocaulaceae are a family of lichen-forming fungi in the order Lecanorales. It contains five genera. Species of this family are widely distributed in temperate boreal and austral regions. Genera *'' Hertelidea'' – 6 spp. *''Lepraria ...

. It has a cosmopolitan distribution. In

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...

, it has the

conservation status The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservatio ...

of a

vulnerable species A vulnerable species is a species which has been categorized by the International Union for Conservation of Nature as being threatened with extinction unless the circumstances that are threatening its survival and reproduction improve. Vulne ...

(VU).Náttúrufræðistofnun Íslands celandic Institute of Natural History(1996).
Válisti 1: Plöntur.
' (in Icelandic) Reykjavík: Náttúrufræðistofnun Íslands.

Ecology

''Stereocaulon paschale'' is host to some

lichenicolous fungi A lichenicolous fungus is a parasitic fungus that only lives on lichen as the host. A lichenicolous fungus is not the same as the fungus that is the component of the lichen, which is known as a lichenized fungus. They are most commonly specific ...

which infect various parts of the

thallus Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or " twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms ...

. Most of these fungi have a

Holarctic distribution The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical region ...

. These fungi include: * '' Arthonia stereocaulina'', Infects the phyllocladia but rarely causes disease. * ''

Catillaria stereocaulorum ''Catillaria'' is a genus of crustose lichens in the family Catillariaceae. The genus was circumscribed by Italian lichenologist Abramo Bartolommeo Massalongo in 1852. It is the type genus of Catillariaceae, which was circumscribed by Austrian l ...

'', Mainly infects the phyllocladia, which can become swollen and dark. It is common in the Arctic. * ''

Cercidospora stereocaulorum ''Cercidospora stereocaulorum'' is a species of lichenicolous fungus in the genus ''Cercidospora'' but it has not been assigned to a family. It is known to parasitise lichens of the genus ''Stereocaulon''. Similar species Cercidospora stereoca ...

'', Infects phyllocladia and sometimes on stems, cephalodia and apothecia. * ''

Endococcus nanellus ''Endococcus nanellus'' is a species of lichenicolous fungus in the order Dothideales. It is known from Alaska, Canada, Greenland, Hawaii, Japan, Russia, South-Korea, and Kazakhstan. Host species ''Endococcus nanellus'' is known to infect numer ...

'', 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 ''Pertusaria'' is a large genus of warty crustose lichens in the Pertusariaceae family.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, The fruiting bodies are usually modified apothecia that immersed in warts ...

'' or ''

Ochrolechia ''Ochrolechia'' is a genus of crustose lichens in the family Ochrolechiaceae. Species , Species Fungorum accepts 38 species of ''Ochrolechia'': *''Ochrolechia aegaea'' *''Ochrolechia africana'' *''Ochrolechia alaskana'' *''Ochrolechia altic ...

''. * ''

Polycoccum trypethelioides ''Polycoccum'' is a genus of lichenicolous fungi in the family Polycoccaceae. It has about 60 species. Species *''Polycoccum acarosporicola'' *''Polycoccum aksoyi'' *''Polycoccum alboatrum'' *'' Polycoccum amygdalariae'' *''Polycoccum anato ...

'', Produces galls on stem which change colour with time turning cinnamon colour or brown.

References

Stereocaulaceae Lichen species Taxa named by Carl Linnaeus Lichens described in 1753 Cosmopolitan species {{Lecanorales-stub