''Cetraria aculeata'' or the spiny Iceland lichen is a dark brown to black

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 ...

, soil Iceland lichen from the family

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 ...

. The species was first described by German naturalist Johann Christian Daniel Edler von Schreber in 1771 under the name of ''Lichen aculeatus''. Later on

Erik Acharius Erik Acharius (10 October 1757 – 14 August 1819) was a Swedish botanist who pioneered the taxonomy of lichens and is known as the "father of lichenology." Acharius was famously the last pupil of Carl Linnaeus. Life Acharius was born in ...

, the "father of lichenology" gave it a name of ''Cornicularia aculeata'', which lately has been changed to ''Coelocaulon aculeatum''. Finally the

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

revision of

Ingvar Kärnefelt Jan Eric Ingvar Kärnefelt (born 1944) is a Swedish lichenologist. Early life and education Kärnefelt was born in Gothenburg, Sweden in 1944. His initial goal in his higher-level studies at University of Cologne in 1966–1967 was to become ...

and colleagues assigned the species to the genus ''

Cetraria ''Cetraria'' is a genus of fruticose lichens that associate with green algae as photobionts. Most species are found at high latitudes, occurring on sand or heath. Species have a characteristic "strap-like" form, with spiny lobe edges. '' Cetra ...

''. The thalli of ''Cetraria aculeata'' form shrubby tufts of up to 1–5 cm height, main branches are from 1 to 4 mm wide, terminal branches up to 1 mm wide, chemical tests K - and P -. The species is found fertile, and seems to propagate mainly by thallus fragmentation. Despite the apparent lack of

ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...

s, which can be dispersed across long distances, ''C. aculeata'' has a very wide distribution. It is frequent in open polar and

boreal Boreal may refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernander sequence of northern Europe, during the Holocene epoch *Boreal climate, a climate characterized by long winters and short, cool to mild ...

environments from the maritime Antarctic to the high Arctic. At intermediate latitudes it is mostly found in high mountain ecosystems, as well as its distributional range also extends into forest gaps, woodland and

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, ...

ecosystems, or coastal and

riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...

sand deposits of the Mediterranean and

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

zones. There are several morphologically very similar and genetically closely related species that are united under the name of ''Cetraria aculeata complex''. It consists of as many as six species: ''C. muricata'', ''C. crespoae'', ''C. steppae'', ''C. odontella'', ''C. australiensis'' and not published yet ''C. panamericana''.Lutsak T, Fernández-Mendoza F, Nadyeina O, Pérez-Ortega S & Printzen C (2012) ''Cetraria steppe'': a lichen species of central Asian steppes, or part of a wider Mediterranean clade of ''C. aculeata''? In Abstracts of the 21st International Symposium ‘‘Biodiversity and Evolutionary Biology’’ of the German Botanical Society (DBG), 126. The phenomenon observed is due to existence of so-called

cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, which has been reported for many groups of organisms.

Ecology

''Cetraria aculeata'' is a known

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

to several

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 ...

species, including ''

Lichenopeltella cetrariicola ''Lichenopeltella cetrariicola'' is a species of lichenicolous fungus belonging to the class Dothideomycetes. It has been reported from Europe and Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean a ...

'', '' Acremonium lichenicola'', '' Clypeococcum cetrariae'', '' Didymocyrtis cladoniicola'', '' Didymocyrtis trassii'', '' Endococcus parmeliarum'', '' Lichenoconium eroden'', '' Eonema pyriforme'', '' Katherinomyces cetrariae'', '' Sphaerellothecium aculeatae'', and '' Taeniolella rolfii''.

References

{{Taxonbar, from=Q8344425 Parmeliaceae Lichen species Lichens of Antarctica Lichens of Europe Lichens described in 1771 Taxa named by Johann Christian Daniel von Schreber