''Placopsis perrugosa'' is a saxicolous (rock-dwelling), placodioid

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Trapeliaceae Trapeliaceae is a family of lichens in the order Baeomycetales. The family contains 12 genera and about 125 species. Taxonomy Trapeliaceae was originally circumscribed by French lichenologist Maurice Choisy in 1929. Hannes Hertel emended the f ...

.What is a lichen?, Australian National Botanical Garden
/ref> It was formally described as a new species in 1867 by Finnish lichenologist William Nylander, originally as a member of the genus ''

Lecanora ''Lecanora'' is a genus of lichen commonly called rim lichens.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, Lichens in the genus ''Squamarina'' are also called rim lichens. Members of the genus have roughly ci ...

''. After the retreat of the Glaciar Frías in the Patagonian Andes, Argentina, ''Placopsis perrugosa'' dominated the

pioneer Pioneer commonly refers to a settler who migrates to previously uninhabited or sparsely inhabited land. In the United States pioneer commonly refers to an American pioneer, a person in American history who migrated west to join in settling and dev ...

stage on newly exposed rock outcrops. This was followed by a mid-successional stage, in which a lichen-

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

mat was dominated by the moss ''

Racomitrium lanuginosum ''Racomitrium lanuginosum'' is a widespread species of moss found in montane and arctic tundra, the genus Racomitrium is found across the Northern and Southern hemispheres., however Racomitrium lanuginosum is only found in the Northern hemisphere ...

'', providing the foundation for a larger diversity of

vascular plant Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...

s in the final successional stage. Like other members of genus ''

Placopsis ''Placopsis'' (bullseye lichen) is a genus of lichenized fungi in the family Trapeliaceae. Species , Species Fungorum (via the Catalog of Life) accepts 29 species of ''Placopsis''. *'' Placopsis ampliata'' *'' Placopsis antarctica'' *'' Pla ...

'', ''P. perrugosa'' is a fast-growing crustose lichen; this allows them to dominate as early colonisers on snow-free

moraine A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...

s of exposed land surfaces.

References

Baeomycetales Taxa named by William Nylander (botanist) Lichens described in 1867 Lichen species Lichens of South America {{Lecanoromycetes-stub