''Cetraria laevigata'' is a species of ground-dwelling,

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 mor ...

(bushy)

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Parmeliaceae The Parmeliaceae is a large and diverse family of Lecanoromycetes. With over 2700 species in 71 genera, it is the largest family of lichen-forming fungi. The most speciose genera in the family are the well-known groups: '' Xanthoparmelia'' ( 822 ...

. It was formally described as a new species by Russian lichenologist Kseniya Aleksandrovna Rassadina in 1943. In North America, it is commonly known as the striped Iceland lichen.

Description

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 wer ...

of ''Cetraria laevigata'' is pale brown, with an even paler underside. It comprises smooth and shiny, narrow lobes measuring 1–3 mm across. It has

pseudocyphella Pseudocyphellae (singular ''pseudocyphella'') are structures in lichens that appear as tiny pores on the outer surface (the cortex of the lichen. They are caused when there is a break in the cortex of the lichen, and the medullary hyphae extend t ...

e (tiny pores for gas exchange) on its margins. The major

lichen product Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol deriva ...

s in ''Cetraria laevigata'' are fumarprotocetraric acid, protolichesterinic acid, and lichesterinic acids. The expected results of standard

lichen spot tests A spot test in lichenology is a spot analysis used to help identify lichens. It is performed by placing a drop of a chemical on different parts of the lichen and noting the colour change (or lack thereof) associated with application of the chemical ...

on the

medulla Medulla or Medullary may refer to: Science * Medulla oblongata, a part of the brain stem * Renal medulla, a part of the kidney * Adrenal medulla, a part of the adrenal gland * Medulla of ovary, a stroma in the center of the ovary * Medulla of th ...

are PD+ (red), K−, KC−, and C−.

Distribution

''Cetraria laevigata'' has an amphiberingian distribution pattern (i.e., on both sides of the Bering Strait), and is found in North America, from

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

through upper Canada, as well as in eastern

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...

. In the

Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

, the lichen has been recorded growing at elevations of up to .

Species interactions

'' Perigrapha cetrariae'' is a

lichenicolous fungus 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 to ...

that grows on ''Cetraria laevigata''. This fungus, described from specimens collected in Japan, does not visibly damage the host thallus or induce

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...

s. '' Echinodiscus kozhevnikovii'' is a lichenicolous fungus that has been recorded growing on ''Cetraria laevigata'' in the

Magadan Oblast Magadan Oblast ( rus, Магаданская область, r=Magadanskaya oblast, p=məgɐˈdanskəjə ˈobləsʲtʲ) is a federal subject (an oblast) of Russia. It is geographically located in the Far East region of the country, and is adminis ...

region of the

Russian Far East The Russian Far East (russian: Дальний Восток России, r=Dal'niy Vostok Rossii, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in Northeast Asia. It is the easternmost part of Russia and the Asian continent; and is admini ...

, while '' Lichenoconium erodens'', '' Clypeococcum cetrariae'', '' Lichenopeltella cetrariae'', and '' Katherinomyces cetrariae'' have been recorded parasitising ''C. laevigata'' from

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...

References

{{Taxonbar, from=Q21156183 Parmeliaceae Lichens described in 1943 Lichens of Japan Lichens of North America Lichens of Subarctic America Lichens of Mongolia Lichens of Siberia Lichens of the Russian Far East Lichens of the Indian subcontinent Lichen species