''Arctomia teretiuscula'' is a rare species of
squamulose
A squamulose lichen is a lichen that is composed of small, often overlapping "scales" called squamules. If they are raised from the substrate and appear leafy, the lichen may appear to be a foliose lichen, but the underside does not have a "skin ...
(scaly)
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.[Arctomiaceae
The Arctomiaceae are a family of lichenized fungi in the Ascomycota, class Baeomycetales. The family was named by Theodor Magnus Fries in 1861, with '' Arctomia'' as the type genus. Species in this family are found in arctic and subarctic habitat ...]
. It is found at high elevations in the mountains between
Tibet and
Sichuan, China.
Taxonomy
The lichen was
formally described as a new species in 2005 by Norwegian lichenologist
Per Magnus Jørgensen. The
type specimen was collected by Walter Obermayer in Haigoulou glacier and forest park (
Mount Gongga
Mount Gongga (), also known as Minya Konka (Khams Tibetan pinyin: ''Mi'nyâg Gong'ga Riwo'') and colloquially as "The King of Sichuan Mountains", is the highest mountain in Sichuan province, China. It has an elevation of above sea level. This m ...
) at an altitude between ; here it was found growing on mossy rocks and soil. Because of its small size and nondescript colour, it is readily missed in the field. Although at the time of publication the lichen was only known to occur at the
type location, Jørgensen speculates that it may have a wider distribution in similar habitats in the Himalayas.
Description
The lichen forms dark brown squamulose
rosettes up to in diameter. Its
thallus is coral-like in form and has a multilayer
cortex with a compact layer of
cyanobionts. Its
ascospores, which number 8 per
ascus
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 ...
, are spindle-shaped (fusiform) and often curved, divided by 6 to 8
septa, and measure 40–60 by 4–5
μm
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
. No
secondary chemicals were detected with the use of
thin-layer chromatography, and all of the standard
chemical spot tests are negative.
''Arctomia teretiuscula'' is similar in appearance to ''
Arctomia delicatula
''Arctomia'' is a genus of lichen-forming fungi in the family Arctomiaceae. The genus was originally circumscribed by Theodor Magnus Fries in 1861. ''Arctomia'' has a circumpolar distribution.
Species
*'' Arctomia delicatula''
*''Arctomia pa ...
''—the
type species of genus ''
Arctomia
''Arctomia'' is a genus of lichen-forming fungi in the family Arctomiaceae. The genus was originally circumscription (taxonomy), circumscribed by Theodor Magnus Fries in 1861. ''Arctomia'' has a circumpolar distribution.
Species
*''Arctomia del ...
''—found in western and northern Europe. The main visible difference between the two is the coralloid thallus of ''A. teretiuscula'' compared to the granular thallus of its European counterpart; other anatomical differences between the two become apparent when their internal microscopic structures are compared.
References
{{Taxonbar, from=Q21237271
Baeomycetales
Lichen species
Lichens described in 2003
Lichens of China
Taxa named by Per Magnus Jørgensen