Stereocaulon ramulosum

{{Short description|Species of lichen}}

{{Speciesbox

| name = Snow lichen

| image = Lichen Stereocaulon Devils Hole.jpg

| image_caption = Barrington Tops National Park, Australia

| genus = Stereocaulon

| species = ramulosum

| synonyms =

• Lichen ramulosus Sw.

| authority = Raeusch.

}}

Stereocaulon ramulosum, commonly known as snow lichen, is a terricolous fruticose lichen belonging to the family Stereocaulaceae.{{cite web |title=Stereocaulon ramulosum |url=https://www.gbif.org/species/7247063 |website=www.gbif.org |access-date=15 February 2021 |language=en}} It has cosmopolitan distribution. In the Australasian region, it is common in eastern Australia, New Zealand and has also been recorded at Lord Howe Island and Macquarie Island.{{cite web |author= |title=Stereocaulon ramulosum |url=https://biocache.ala.org.au/occurrences/search?q=lsid%3ANZOR-6-5277&qualityProfile=ALA#tab_mapView |access-date=February 15, 2021 |publisher=Atlas of Living Australia}}

Its habitat is often cooler, moist areas with a high level of cloud cover. It may be found on rocky ground or as an epiphyte on tree branches. Stereocaulon ramulosum was the first lichen known to contain an amylose polysaccharide.{{cite journal |author=Madalena Baron, Philip A.J. Gorin, Marcello Iacomini |title=Isolation and identification of a linear (1→3)-linked β-d-glucan and other carbohydrate components of the lichen Stereocaulon ramulosum (SW.) Räusch |journal=Carbohydrate Research |url=https://www.sciencedirect.com/science/article/abs/pii/0008621588850572 |access-date=February 15, 2021 |date=1988 |volume=177 |pages=235–239 |publisher=Elsevier|doi=10.1016/0008-6215(88)85057-2 |url-access=subscription }}{{cite web |author= |title=Stereocaulon ramulosum |url=https://www.anbg.gov.au/lichen/photos-captions/stereocaulon-ramulosum-f-364.html |access-date=February 15, 2021 |work=Australian Lichens |publisher=Australian National Herbarium}}

This species is unusual, as the fungal component is associated with two different chlorophyll forming species; usually there is only one. The more significant one is a green alga which gives the lichen its characteristic colour. The second is a cyanobacteria which is found in the cephalodia, a wart-like structure. Three different kingdoms are represented in this single life form; Fungi, Protista and Eubacteria.{{cite web |title=Living on the Edge |url=http://www.wombatforestcare.org.au/newsletters/WombatForestcareNewsletter25_Sept_13.pdf|author = John Walter|publisher = Wombat Forestcare Newsletter - September 2013|access-date=February 15, 2021}}

The generic name Stereocaulon is derived from ancient Greek stereós and Latin caulis, referring to the hard stem of the central part of the lichen.{{cite web |title=Stereocaulon alpinum |work= Association Française de Lichénologie - Les champignons lichénisés de France - AFL |url=https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_S/Text_S/Stereocaulon_alpinum.htm|author = |publisher = Association Française de Lichénologie|access-date=February 17, 2021}} The specific epithet ramulosum is derived from the Latin ramulose, and means "having many small branches".{{cite web |title=Calflora - Page R |work= Botanic Names |url=http://www.calflora.net/botanicalnames/pageR.html|author = Michael L. Charters|publisher = |access-date=February 17, 2021}}