''Stereocaulon ramulosum'', commonly known as snow lichen, is a

terricolous A terricolous lichen is a lichen that grows on the soil as a substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is at ...

fruticose A fruticose lichen is a form of lichen fungi that is characterized by a coral-like shrubby or bushy growth structure. It is formed from a symbiotic relationship of a photobiont such as green algae or less commonly cyanobacteria and one, two or m ...

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 cosmopolitan distribution. In the Australasian region, it is common in eastern Australia,

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

and has also been recorded at

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland ...

and

Macquarie Island Macquarie Island is an island in the southwestern Pacific Ocean, about halfway between New Zealand and Antarctica. Regionally part of Oceania and politically a part of Tasmania, Australia, since 1900, it became a Tasmanian State Reserve in 19 ...

. 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 Amylose is a polysaccharide made of α-D-glucose units, bonded to each other through α(1→4) glycosidic bonds. It is one of the two components of starch, making up approximately 20–30%. Because of its tightly packed helical structure, amylose ...

polysaccharide Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with ...

. This species is unusual, as the fungal component is associated with two different

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to ...

forming species; usually there is only one. The more significant one is a

green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep in the Charophyte alg ...

which gives the lichen its characteristic colour. The second is a cyanobacteria which is found in the

cephalodia {{Short description, Morphological structure found in some lichens Cephalodia (singular cephalodium) are small gall-like structures found in some species of lichens that contain cyanobacterial symbionts. Cephalodia can occur within the tissues ...

, a wart-like structure. Three different

kingdom Kingdom commonly refers to: * A monarchy ruled by a king or queen * Kingdom (biology), a category in biological taxonomy Kingdom may also refer to: Arts and media Television * ''Kingdom'' (British TV series), a 2007 British television drama s ...

s are represented in this single life form;

Fungi A fungus (plural, : fungi or funguses) is any member of the group of Eukaryote, eukaryotic organisms that includes microorganisms such as yeasts and Mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified ...

Protista A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the e ...

and

Eubacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

. The generic name ''

Stereocaulon ''Stereocaulon'' is a genus of lichens. Members of ''Stereocaulon'' are commonly called snow lichens. Species *'' Stereocaulon alpinum'' *'' Stereocaulon apocalypticum'' *''Stereocaulon arcticum'' *''Stereocaulon arenarium'' *''Stereocaulo ...

'' is derived from

ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

''stereós'' and

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

''caulis'', referring to the hard stem of the central part of the lichen. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

ramulosum is derived from the Latin ''ramulose'', and means "having many small branches".

Phytochemistry

The characteristic

secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the no ...

of ''S. ramulosum'' is

atranorin Atranorin is a chemical substance produced by some species of lichen. It is a secondary metabolite belonging to a group of compounds known as depsides. Atranorin has analgesic, anti-inflammatory, antibacterial, antifungal, cytotoxic, antioxidant ...

, a depside. During the extraction phase, atranorin suffer an

alcoholysis In chemistry, solvolysis is a type of nucleophilic substitution (S1/S2) or elimination where the nucleophile is a solvent molecule. Characteristic of S1 reactions, solvolysis of a chiral reactant affords the racemate. Sometimes however, the ster ...

reaction, producing methyl/ethyl haemmatomate and methyl ß-orcinol

carboxylate In organic chemistry, a carboxylate is the conjugate base of a carboxylic acid, (or ). It is an ion with negative charge. Carboxylate salts are salts that have the general formula , where M is a metal and ''n'' is 1, 2,...; ''carbox ...

. Has been identified in New Zealand and in east central Africa, perlatolic acid, anziaic acid and methyl haemmatomate. Methyl haemmatomate has in-vitro antifungical activity. Huneck in Chiloe, Chile, identify atranorin, perlatolic acid and lobaric acid. Also, in Pongo, Bolivia, Vila et al. aislate the polyol galactitol and 1,3,7-trimethylguanine, an unusual alkaloid. Carbohydrates have been found.. A linear (1→3) linked ß-D-glucan, and β-GalCer-lich, a new immune stimulant carbohydrate.

References

{{Taxonbar, from=Q21321251 Lichen species Lichens described in 1797 Stereocaulaceae