Stereocaulon paschale explained

Stereocaulon paschale is a species of lichen belonging to the family Stereocaulaceae.^[1]

It has a cosmopolitan distribution.

In Iceland, it has the conservation status of a vulnerable species (VU).^[2]

Ecology

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.

Notes and References

1. Web site: Stereocaulon paschale (L.) Hoffm. . www.gbif.org . 12 February 2021 . en.
2. Náttúrufræðistofnun Íslands [Icelandic Institute of Natural History] (1996). Válisti 1: Plöntur. (in Icelandic) Reykjavík: Náttúrufræðistofnun Íslands.
3. Zhurbenko . Mikhail P. . 2010 . Lichenicolous fungi and lichens growing on Stereocaulon from the Holarctic, with a key to the known species . Opuscula Philolichenum . 8 . 9-39.