Peltigera gowardii, or western waterfan, is an aquatic lichen found only in mountain streams of Western North America. It is the largest aquatic lichen in the Pacific Northwest.

Peltigera gowardii
Thallus of P. gowardii
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Peltigerales
Family: Peltigeraceae
Genus: Peltigera
Species:
P. gowardii
Binomial name
Peltigera gowardii
Lendemer & H.E.O'Brien (2011)

P. gowardii is currently listed as a species of Special Concern in Canada, as two of five known populations have been extirpated.[1] In the United States, Montana and Alaska list this lichen as an S1 species, at high risk of extirpation,[2] while Washington and California give it a slightly more secure ranking. Rising temperatures and habitat loss are the largest threat to the survival of P. gowardii.[1]

Description edit

P. gowardii is a tripartite lichen, consisting of fungus, alga, and Nostoc cyanobacteria. It has a gelatinous consistency due to living in aquatic or semi-aquatic locations, most often mountain streams or springs above 1,200 m (3,900 ft) elevation.[1][2] It grows in small rosettes attached to rock.[1] It has a dark blue-green to black colour when above water, but becomes olive-green when submerged.[3] It can be distinguished from algae or plants by the distinctive veins along the backside of the thallus, as well as round, brown apothecia present. These apothecia are the sexually reproductive parts of the lichen, and no vegetatively reproductive parts are seen.[1]

P. gowardii is morphologically similar to P. hydrothyria. They are most easily differentiated by geography, with P. gowardii being a western species and P. hydrothyria mainly growing in the east.[4] P. gowardii also has all chemical tests return negative, while P. hydrothyria tests positive for methylgyrophorate.[4]

References edit

  1. ^ a b c d e COSEWIC. 2013. COSEWIC assessment and status report on the Western Waterfan Peltigera gowardii in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xi + 39 pp. (www.registrelep-sararegistry.gc.ca/default_e.cfm).
  2. ^ a b Webmaster, David Ratz. "Western Waterfan Lichen - Montana Field Guide". fieldguide.mt.gov. Retrieved 2021-08-03.
  3. ^ "Ways of Enlichenment - Lichens of North America". www.waysofenlichenment.net. Retrieved 2021-08-03.
  4. ^ a b Lendemer, J.C., and H. O'Brien. 2011. How do you reconcile molecular and non-molecular datasets? A case study where new molecular data prompts a revision of Peltigera hydrothyria s.l. in North America and the recognition of two species. Opuscula Philolichenum, 9: 99–110.