Gowardia_nigricans

<i>Gowardia nigricans</i>

Gowardia nigricans

Species of lichen

Gowardia nigricans, commonly known as the gray hair lichen or gray witch's hair, is a species of fruticose lichen in the family Parmeliaceae.

Quick Facts Gowardia nigricans, Scientific classification ...

Taxonomy

The lichen was first formally described by Swedish lichenologist Erik Acharius in 1810, as Cornicularia ochroleuca var. nigricans.[2] William Nylander promoted it to distinct species status in 1862, as Alectoria nigricans.[3] A colloquial name used in North America for the lichen is "gray witch's hair".[4]

The form Alectoria nigricans f. goemerensis was proposed by Hungarian lichenologist Vilmos Kőfaragó-Gyelnik in 1932.[5] The form Alectoria nigricans f. subchalybeiformis was suggested by Veli Räsänen in 1944.[6] They are no longer considered to have independent taxonomic significance.[1]

In 2009, Finnish lichenologists Pekka Halonen, Leena Myllys, Saara Velmala and Heini Hyvärinen proposed the new genus Gowardia, segregated from Alectoria based on phylogeny, morphology, secondary chemistry, ecology and distribution. They assigned Gowardia nigricans as the type species.[7]

Description

The shrubby thallus of Gowardia nigricans grows erect or tangled on the ground. Its main branches vary in colour from pale pinkish to nearly black, but they always have black branch tips. The surface is almost always dull. Large brown apothecia are sometimes produced.[4]

The expected results of standard chemical spot tests are: cortex and medulla PD+ (yellow), K+ (yellow), KC+ (red), C+ (pink). The colour reactions in very dark specimens can be difficult to visualize.[4]

Habitat and distribution

In habitat with Thamnolia vermicularis. Ukok Pletau, East Kazakhstan region, Katon-Karagay National Park

Although Gowardia nigricans typically grows on the soil, often in tundra heath, it sometimes grows on the low branches of trees or shrubs.[4]

In Antarctica, it is found in the South Orkney Islands.[8] It has also been recorded from Greenland[9] and New Zealand.[10]

Chemistry

Gowardia nigricans contains alectorialic acid, barbatolic acid, alectorialin, and 5,7-dihydroxy-6-methylphthalide.[11] Alectorialic acid has been investigated for its antiviral properties.[12]

Ecology

A study of the growth rates of various lichens consumed by grazing reindeer in Svalbard showed that Gowardia nigricans has a mean growth rate of 2.43 milligrams per gram, corresponding to a 2.5% seasonal increase in percentage of mass over 10 weeks. This was the lowest growth rate of several lichens studies, and it confirmed the conclusion of previous studies that showed that reindeer grazing damages the lichen and its slow growth hampers subsequent reestablishment.[13]

Biomonitoring

A study has shown that Gowardia nigricans could be useful as an indicator species to monitor air pollution.[14]

References

  1. [1]
    "Synonymy:Gowardia nigricans (Ach.) Halonen, Myllys, Velmala & Hyvärinen". Species Fungorum. Retrieved 4 May 2021.
  2. [2]
    Acharius, Erik (1810). Lichenographia Universalis. Lichenographia Universalis (in Latin). Gottingen: Apud Iust. Frid. Danckwerts. p. 615.
  3. [3]
    Nylander, W. (1861). "Lichenes Scandinaviae sive prodromus lichenographiae Scandinaviae". Notiser ur Sällskapets pro Fauna et Flora Fennica Förhandlingar (in Latin). 5: 71.
  4. [4]
    Brodo, Irwin M.; Sharnoff, Sylvia Duran; Sharnoff, Stephen (2001). Lichens of North America. New Haven: Yale University Press. p. 153. ISBN 978-0-300-08249-4.
  5. [5]
    Gyelnik, V. (1932). "Alectoria Studien". Nytt Magazin for Naturvidenskapene. 70: 35–62.
  6. [6]
    Räsänen, V. (1944). "Lichenes novi I". Annales Botanici Societatis Zoologicae Botanicae Fennicae "Vanamo". 20 (3): 1–34.
  7. [7]
    Halonen, Pekka; Myllys, Leena; Velmala, Saara; Hyvärinen, Heini (2009). "Gowardia (Parmeliaceae)—a new alectorioid lichen genus with two species". The Bryologist. 112 (1): 138–146. doi:10.1639/0007-2745-112.1.138.
  8. [8]
    Mackenzie Lamb, I. (1964). Antarctic Lichens. The genera Usnea, Ramalina, Himantormia, Alectoria, Cornicularia (PDF) (Report). British Antarctic Survey. pp. 24–35.
  9. [9]
    Hawksworth, David L. (1968). "Lichens from Tugtilik, East Greenland". The Bryologist. 71 (1): 52–54. doi:10.2307/3240657.
  10. [10]
    Jørgensen, P. M.; Galloway, D. J. (1983). "Bryoria (lichenised Ascomycotina) in New Zealand". New Zealand Journal of Botany. 21 (3): 335–340. doi:10.1080/0028825X.1983.10428562.
  11. [11]
    Elix, J.A.; Jayanthi, V.K. (1987). "Synthetic confirmation of the structure of the lichen benzyl esters alectorialic and barbatolic acids". Australian Journal of Chemistry. 40 (11): 1841–1850. doi:10.1071/CH9871841.
  12. [12]
    Odimegwu, Damian C.; Ngwoke, Kenneth; Ejikeugwu, Chika; Esimone, Charles O. (2019). "Lichen secondary metabolites as possible antiviral agents". In Ranković, Branislav (ed.). Lichen Secondary Metabolites. Bioactive Properties and Pharmaceutical Potential (2nd ed.). Cham, Switzerland: Springer Nature Switzerland. pp. 199–214. ISBN 978-3-030-16814-8.
  13. [13]
    Cooper, Elisabeth J.; Wookey, Philip A. (2001). "Field measurements of the growth rates of forage lichens, and the implications of grazing by Svalbard Reindeer" (PDF). Symbiosis. 31: 173–186.
  14. [14]
    Bashkin, Vladimir N.; Barsukov, Pavel A.; Arabsky, Anatoly K. "Specific Reaction of Biota to Environmental Pollution in Tundra Ecosystems". In Bashkin, Vladimir N. (ed.). Biogeochemical Technologies for Managing Pollution in Polar Ecosystems. Environmental Pollution. Vol. 26. Springer International Publishing. pp. 73–85. ISBN 978-3-319-41805-6.
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