Arthonia radiata
| Arthonia radiata | |
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Arthoniomycetes |
| Order: | Arthoniales |
| Family: | Arthoniaceae |
| Genus: | Arthonia |
| Species: | A. radiata
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| Binomial name | |
| Arthonia radiata | |
| Synonyms[1] | |
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List
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Arthonia radiata, the asterisk lichen,[2] is a common and widepspread species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae.[3]
Taxonomy
[edit]Arthonia radiata is the type species of the genus Arthonia. It was first formally described by Christiaan Hendrik Persoon in 1794, who called it Opegrapha radiata.[4] Erik Acharius transferred it to the genus Arthonia in 1808.[5] It has been known by many names in its lengthy taxonomic history.[1]
The genome of Arthonia radiata has been sequenced and assembled. The draft genome is approximately 33.5 megabases in size, contains 6,931 annotated genes, and consists of 16.65% repeat sequences, predominantly LTR elements.[6]
Description
[edit]Arthonia radiata is a crustose lichen with an immersed thallus, often separated from its surroundings by a thin brown line. The thallus is typically pale, ranging from white to pale grey, sometimes with a brown or olive tinge, and often forms a mosaic-like pattern on its substrate. Its reproductive structures, called apothecia, are black and can appear in various shapes—rounded, star-like (stellate), or elongated. These apothecia can measure between 0.15 and 2.2 mm across, and are usually flat or slightly convex. They lack a frosted appearance, often referred to as being non-pruinose.[7]
Under a microscope, the apothecia have a thin epithecium (the upper layer) that is brown or olive-brown, reacting to certain chemical tests by turning pale green. The internal structure includes a clear hymenium (spore-producing layer) and a hypothecium (the layer beneath) that is also colourless to pale olive-brown. The paraphysoids (sterile filaments within the hymenium) are narrow, 1–2 μm wide, but can expand to 3 μm, and they are often capped with darker brown tips.[7]
Arthonia radiata produces spores that are cylindric-obovoid to cylindrical, with 3 internal walls (septa) dividing the spore into 4 cells. These ascospores measure between 15 and 20 μm long and 4.5 to 6 μm wide, and the uppermost cell is not enlarged. While its asexual reproductive structures, pycnidia, are rare, they are immersed in the thallus and black, with a pale green reaction in chemical tests. These structures release small, rod-like conidia (asexual spores), about 4–5 μm long.[7]
No secondary metabolites, often used to identify lichen species, have been detected in Arthonia radiata using thin-layer chromatography.[7]
Habitat and distribution
[edit]Arthonia radiata is a widespread and common species. It grows on the smooth bark of many trees and shrubs.[7]
Species interactions
[edit]Lichenicolous fungi that have been recorded growing on Arthonia radiata include Muellerella polyspora, Stigmidium arthoniae, and an undescribed species of Opegrapha.[7]
See also
[edit]References
[edit]- ^ a b "GSD Species Synonymy. Current Name: Arthonia radiata (Pers.) Ach., K. Vetensk-Acad. Nya Handl. 29: 131 (1808)". Species Fungorum. Retrieved 20 October 2024.
- ^ Brodo, Irwin M.; Sharnoff, Sylvia Duran; Sharnoff, Stephen (2001). Lichens of North America. Yale University Press. p. 165. ISBN 978-0-300-08249-4.
- ^ "Arthonia radiata (Pers.) Ach". Catalogue of Life. Species 2000: Leiden, the Netherlands. Retrieved 20 October 2024.
- ^ Persoon, C.H. (1794). "Einige Bemerkungen über die Flechten: nebst Beschreibungen einiger neuen Arten aus dieser Familie der Asermoose" [Some remarks about lichens: along with descriptions of several new species from this family of cryptogams]. Annalen der Botanik (Usteri) (in German). 7: 1–32 [29].
- ^ Acharius, E. (1808). "Förteckning på de i Sverige våxande arter af Lafvarnas Familj" [List of the species of the family of lichens growing in Sweden]. Kongliga Vetenskaps Academiens Nya Handlingar. 29: 125–132.
- ^ Armstrong, Ellie E.; Prost, Stefan; Ertz, Damien; Westberg, Martin; Frisch, Andreas; Bendiksby, Mika (2018). "Draft Genome Sequence and Annotation of the Lichen-Forming Fungus Arthonia radiata". Genome Announcements. 6 (14). doi:10.1128/genomea.00281-18. hdl:11250/2586923.
- ^ a b c d e f Cannon, P.; Ertz, D.; Frisch, A.; Aptroot, A.; Chambers, S.; Coppins, B.; Sanderson, N.; Simkin, J.; Wolselsey, P. (2020). Arthoniales: Arthoniaceae, including the genera Arthonia, Arthothelium, Briancoppinsia, Bryostigma, Coniocarpon, Diarthonis, Inoderma, Naevia, Pachnolepia, Reichlingia, Snippocia, Sporodophoron, Synarthonia and Tylophoron. Revisions of British and Irish Lichens. Vol. 1. pp. 24–25. doi:10.34885/173.